Work Health and Safety (Managing Risks of Hazardous Chemicals in the Workplace) Code of Practice 2015 (Cth)
Work Health and Safety (Managing Risks of Hazardous Chemicals in the Workplace) Code of Practice 2015
made under the
Work Health and Safety Act 2011, section 274 (Approved Codes of Practice)
1 Name of instrument
This instrument is the Work Health and Safety (Managing Risks of Hazardous Chemicals in the Workplace) Code of Practice 2015.
2 Commencement
This instrument commences on the day after it is registered on the Federal Register of Legislative Instruments.
3 Code of Practice Approval
I approve the Managing Risks of Hazardous Chemicals in the Workplace Code of Practice. I am satisfied that this code of practice was developed by a process described in section 274(2) of the Work Health and Safety Act 2011.
Michaelia Cash
Minister for Employment17 December 2015
Date
MANAGING RISKS OF
HAZARDOUS CHEMICALS
IN THE WORKPLACECode of Practice
TABLE OF CONTENTS
FOREWORD...................................................................................................................................... 5
1. ... INTRODUCTION...................................................................................................................... 7
1.1 What are hazardous chemicals?................................................................................................ 7
1.2 Who has health and safety duties in relation to hazardous chemicals?..................................... 7
1.3 What is required to manage the risks associated with hazardous chemicals?.......................... 8
1.4 Prohibited and restricted hazardous chemicals........................................................................ 10
1.5 Exposure standards.................................................................................................................. 10
1.6 Preparing a register and manifest of hazardous chemicals..................................................... 10
2. ... IDENTIFYING HAZARDS..................................................................................................... 12
2.1 How to identify which chemicals are hazardous...................................................................... 12
2.2 Safety Data Sheets (SDS)....................................................................................................... 13
2.3 Labels........................................................................................................................................ 15
2.4 Other sources of information.................................................................................................... 16
3. ... ASSESSING RISKS.............................................................................................................. 17
3.1 Decide who should do the assessment.................................................................................... 17
3.2 Decide what sort of risk assessment is appropriate................................................................. 18
3.3 Things to consider in assessing health risks............................................................................. 19
3.4 How to assess physicochemical risks...................................................................................... 23
4. ... CONTROLLING RISKS........................................................................................................ 28
4.1 The hierarchy of control............................................................................................................ 28
4.2 Specific control measures........................................................................................................ 33
4.3 Maintaining control measures................................................................................................... 39
4.4 Providing information, training, instruction and supervision..................................................... 40
5. ... MONITORING AND REVIEW............................................................................................... 41
5.1 Health monitoring...................................................................................................................... 41
5.2 Reviewing control measures.................................................................................................... 42
6. ... EMERGENCY PREPAREDNESS...................................................................................... 44
6.1 Emergency plan........................................................................................................................ 44
6.2 Emergency equipment and safety equipment......................................................................... 46
6.3 Fire protection systems............................................................................................................. 47
6.4 Monitors and alarms................................................................................................................. 48
6.5 Automatic sprinkler systems..................................................................................................... 48
6.6 Water supply............................................................................................................................. 48
APPENDIX A – THE MEANING OF KEY TERMS................................................................... 49
APPENDIX B – COMPARISON OF HAZARD CLASSES AND CATEGORIES UNDER THE ADG CODE AND THE GHS...................................................................................................................... 52
APPENDIX C – PROHIBITED CARCINOGENS, RESTRICTED CARCINOGENS AND RESTRICTED HAZARDOUS CHEMICALS............................................................................................... 54
APPENDIX D – PLACARD AND MANIFEST QUANTITIES................................................. 57
APPENDIX E – REQUIREMENTS FOR HEALTH MONITORING....................................... 61
APPENDIX F – OVERVIEW OF A RISK ASSESSMENT PROCESS.................................. 63
APPENDIX G – RISK ASSESSMENT CHECKLIST............................................................... 64
APPENDIX H – EXAMPLES OF COMMON FUEL AND OXYGEN SOURCES................. 66
APPENDIX I – FIRE AND EXPLOSION RISKS....................................................................... 67
APPENDIX J – PRACTICAL EXAMPLES OF CONTROL MEASURES............................. 70
APPENDIX K – CASE STUDIES................................................................................................ 76
FOREWORDThis Code of Practice on how to manage the risks associated with hazardous chemicals in the workplace is an approved code of practice under section 274 of the Work Health and Safety Act (the WHS Act).
An approved code of practice is a practical guide to achieving the standards of health, safety
and welfare required under the WHS Act and the Work Health and Safety Regulations (the WHS Regulations).A code of practice applies to anyone who has a duty of care in the circumstances described in
the code. In most cases, following an approved code of practice would achieve compliance with the health and safety duties in the WHS Act, in relation to the subject matter of the code.
Like regulations, codes of practice deal with particular issues and do not cover all hazards or risks that may arise. The health and safety duties require duty holders to consider all risks associated with work, not only those for which regulations and codes of practice exist.Codes of practice are admissible in court proceedings under the WHS Act and Regulations.
Courts may regard a code of practice as evidence of what is known about a hazard, risk or control and may rely on the code in determining what is reasonably practicable in the circumstances to which the code relates.Compliance with the WHS Act and Regulations may be achieved by following another method, such as a technical or an industry standard, if it provides an equivalent or higher standard of work health and safety than the code.
An inspector may refer to an approved code of practice when issuing an improvement or prohibition notice.
This Code of Practice has been developed by Safe Work Australia as a model code of practice under the Council of Australian Governments’ Inter-Governmental Agreement for Regulatory and Operational Reform in Occupational Health and Safety for adoption by the Commonwealth, state and territory governments.
Scope and application
This Code provides practical guidance on how to manage health and safety risks associated with hazardous chemicals for persons conducting a business or undertaking who use chemicals in their workplace.
A person conducting a business or undertaking can be a manufacturer, importer or supplier of hazardous chemicals, or a business owner who uses, handles, generates or stores hazardous chemicals at their workplace.
This Code applies to:
· substances, mixtures and articles used, handled, generated or stored at the workplace which are defined as hazardous chemicals under the WHS Regulations
· the generation of hazardous chemicals from work processes, for example toxic fumes released during welding.
This Code does not apply to the transportation of dangerous goods, which is subject to State
and Territory laws based on the requirements under the Australian Code for the Transport of Dangerous goods by Road and Rail (ADG Code).Manufacturers, importers or suppliers of hazardous chemicals that are used, or are likely to be used, in workplaces should refer to the following Codes of Practice:
· Preparation of Safety Data Sheets for Hazardous Chemicals
· Labelling of Workplace Hazardous Chemicals
If you use, handle or store hazardous chemicals listed in Schedule 14 of the WHS Regulations you should also refer to the Health Monitoring Guide. Where these types of hazardous chemicals are used, handled or stored at or above the prescribed threshold quantities, the guidance material for Major Hazard Facilities should be referred to.
Guidance for work involving asbestos or asbestos containing materials is available in the following Codes of Practice:
· How to Manage and Control Asbestos in the Workplace
· How to Safely Remove Asbestos.
Implementation of the Globally Harmonised System of Classification and Labelling
of Chemicals (GHS)The WHS Regulations implement a system of chemical hazard classification, labelling and safety data sheets (SDS) requirements based on the GHS. Transition to the GHS will occur over a 5 year period from 1 January 2012 until 31 December 2016.
This Code refers to hazard classes and categories under the GHS, however, it also applies to workplace hazardous substances and dangerous goods classified under the NOHSC Approved Criteria and the ADG Code, respectively. Most substances and mixtures that are dangerous goods under the ADG Code are also hazardous chemicals. Any person conducting a business of undertaking has a responsibility under WHS laws to manage the risks from all hazardous chemicals, including those that are dangerous goods.
How to use this code of practice
In providing guidance, the word ‘should’ is used in this Code to indicate a recommended course
of action, while ‘may’ is used to indicate an optional course of action.This Code also includes various references to provisions of the WHS Act and Regulations which set out the legal requirements. These references are not exhaustive. The words ‘must’, ‘requires’ or ‘mandatory’ indicate that a legal requirement exists and must be complied with.
1. INTRODUCTION
1.1 What are hazardous chemicals?
Under the WHS Regulations, a hazardous chemical is any substance, mixture or article that satisfies the criteria of one or more Globally Harmonised System of Classification and Labelling of Chemicals (GHS) hazard classes, including a classification in Schedule 6 of the WHS Regulations.
However, some hazard classes and categories of the GHS are excluded by the WHS Regulations. See Appendix A for the definition of ‘hazardous chemical’ and other terms used in this Code.
Most substances and mixtures that are dangerous goods under the ADG Code are hazardous chemicals, except those that have only radioactive hazards (class 7 dangerous goods), infectious substances (division 6.2) and most class 9 (miscellaneous) dangerous goods.
A comparison of dangerous goods classifications under the ADG code with those under the GHS
is provided in Appendix B.In relation to chemicals, a hazard is a set of inherent properties of the substance, mixture, article
or process that may cause adverse effects to organisms or the environment. There are two broad types of hazards associated with hazardous chemicals which may present an immediate or long term injury or illness to people. These are:· Health hazards – These are properties of a chemical that have the potential to cause adverse health effects. Exposure usually occurs through inhalation, skin contact or ingestion. Adverse health effects can be acute (short term) or chronic (long term). Typical acute health effects include headaches, nausea or vomiting and skin corrosion, while chronic health effects include asthma, dermatitis, nerve damage or cancer.
· Physicochemical hazards – These are physical or chemical properties of the substance, mixture or article that pose risks to workers other than health risks, as they do not occur as
a consequence of the biological interaction of the chemical with people. They arise through inappropriate handling or use and can often result in injury to people and/or damage to property as a result of the intrinsic physical hazard. Examples of physicochemical hazards include flammable, corrosive, explosive, chemically reactive and oxidising chemicals.Many chemicals have both health and physicochemical hazards.
1.2 Who has health and safety duties in relation to hazardous chemicals?
Under the WHS Act, a person conducting a business or undertaking has the primary duty to ensure, so far as is reasonably practicable, that the health and safety of workers and other persons are not put at risk from work carried out as part of the conduct of the business or undertaking.
This includes ensuring the safe use, handling and storage of substances.The WHS Regulations include specific duties for a person conducting a business or undertaking
to manage the risks to health and safety associated with using, handling, generating and storing hazardous chemicals at a workplace. The duties include:· correct labelling of containers and pipework, using warning placards and outer warning placards and displaying of safety signs
· maintaining a register and manifest (where relevant) of hazardous chemicals and providing notification to the regulator of manifest quantities if required
· identifying risk of physical or chemical reaction of hazardous chemicals and ensuring the stability of hazardous chemicals
· ensuring that exposure standards are not exceeded
· provision of health monitoring to workers
· provision of information, training, instruction and supervision to workers
· provision of spill containment system for hazardous chemicals if necessary
· obtaining the current Safety Data Sheet (SDS) from the manufacturer, importer or supplier
of the chemical· controlling ignition sources and accumulation of flammable and combustible substances
· provision and availability of fire protection, fire fighting equipment and emergency and safety equipment
· preparing an emergency plan if the quantity of a class of hazardous chemical at
a workplace exceeds the manifest quantity for that hazardous chemical· stability and support of containers for bulk hazardous chemicals including pipework and attachments
· decommissioning of underground storage and handling systems
· notifying the regulator as soon as practicable of abandoned tanks in certain circumstances
The WHS Regulations contain prohibitions or restrictions on certain hazardous chemicals (e.g. certain carcinogens) except in specified circumstances and a restriction on the age of a person who can supply hazardous chemicals.
There are also duties relating to the building, operation and management of pipelines used for the transfer of hazardous chemicals.
Designers, manufacturers, importers and suppliers of substances must also ensure, so far as is reasonably practicable, that the substance they design, manufacture, import or supply is without risks to health and safety. Under the WHS Regulations, manufacturers and importers must correctly classify hazardous chemicals.
The WHS Regulations also impose duties on importers, manufacturers and suppliers relating to the preparation of safety data sheets (SDS), the disclosure of ingredients, packing, labelling and supply of hazardous chemicals.
Officers, such as company directors, have a duty to exercise due diligence to ensure that the business or undertaking complies with the WHS Act and Regulations. This includes taking reasonable steps to ensure that the business or undertaking has and uses appropriate resources and processes to eliminate or minimise risks that arise from hazardous chemicals at the workplace.
Workers have a duty to take reasonable care for their own health and safety and must not adversely affect the health and safety of other persons. Workers must comply with any reasonable instruction and cooperate with any reasonable policy or procedure relating to the use, handling and storage of hazardous chemicals at the workplace.
1.3 What is required to manage the risks associated with hazardous chemicals?
Regulation 351: A person conducting a business or undertaking must manage risks associated with using, handling, generating or storing of hazardous chemicals at a workplace.
Regulation 32-38: In order to manage risk under the WHS Regulations, a duty holder must:
a) identify reasonably foreseeable hazards that could give rise to the risk
b) eliminate the risk so far as is reasonably practicable
c) if it is not reasonably practicable to eliminate the risk – minimise the risk so far as is reasonably practicable by implementing control measures in accordance with the hierarchy of risk control
d) maintain the implemented control measure so that it remains effective
e) review, and if necessary revise all risk control measures so as to maintain, so far as is reasonably practicable, a work environment that is without risks to health and safety.
This Code provides guidance on how to manage the risks associated with hazardous chemicals in the workplace by following a systematic process that involves:
· identifying hazards
· if necessary, assessing the risks associated with these hazards
· eliminating or minimising the risks by implementing and maintaining control measures
· reviewing control measures to ensure they are effective.
When managing the risks, regard must be had to the following factors:
· the hazardous properties of the hazardous chemical
· any potentially hazardous reaction (chemical or physical) between the hazardous chemical and another substance or mixture, including a substance that may be generated by the reaction
· the nature of the work to be carried out with the hazardous chemical
· any structure, plant or system of work that:
o is used in the use, handling, generation or storage of the hazardous chemical
o could interact with the hazardous chemical at the workplace.
Guidance on the general risk management process is available in the Code of Practice: How to Manage Work Health and Safety Risks.
Consulting your workers
Section 47: The WHS Act requires that you consult, so far as is reasonably practicable, with workers who carry out work for you who are (or are likely to be) directly affected by a work health and safety matter.
Section 48: If the workers are represented by a health and safety representative, the consultation must involve that representative.
Consultation with workers and their health and safety representatives is a critical step of managing work health and safety risks. Consulting with and involving workers in the risk management process can assist in ensuring that safety instructions and safe work practices are complied with.
Health and safety representatives must have access to relevant information on matters that can affect the health and safety of workers, for example, hazardous chemicals register and data from monitoring airborne contaminants.
Consulting, co-operating and co-ordinating activities with other duty holders
Section 46: The WHS Act requires that you consult, co-operate and co-ordinate activities with all other persons who have a work health or safety duty in relation to the same matter, so far as is reasonably practicable.
Sometimes you may share responsibility for a health and safety matter with other business operators who are involved in the same activities or who share the same workplace. In these situations, you should exchange information to find out who is doing what and work together in
a co-operative and co-ordinated way so that all risks are eliminated or minimised as far as reasonably practicable.For example, if you engage a contractor to carry out cleaning at your workplace that involves
the use of chemicals, you should find out what is being used, whether there are any hazards associated with the chemicals and how the risks will be controlled. This might, for example,
include jointly preparing a risk assessment for the chemicals being used, how they will be handled and measures that should be taken to eliminate or minimise exposure. After the risk assessment has been prepared, it is important for all duty holders to co-operate and co-ordinate activities with each other to implement the control measures.Further guidance on consultation is available in the Code of Practice: Work Health and Safety Consultation, Co-operation and Co-ordination.
1.4 Prohibited and restricted hazardous chemicals
The WHS Regulations prohibit or restrict the use, storage or handling of certain hazardous chemicals in certain situations. For example, substances containing arsenic must not be used in spray painting or abrasive blasting, while a number of carcinogens such as 4-nitrodiphenyls are prohibited from all uses except for genuine research or analysis authorised by the regulator. Certain chemicals can be used, handled or stored in the workplace after receiving approval from the regulator. Schedule 10 of the WHS Regulations provides further information on the hazardous chemicals that are restricted or prohibited for use (see Appendix C of this Code).
1.5 Exposure standards
Regulation 49: A person conducting a business or undertaking must ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the relevant exposure standard for the substance or mixture.
Exposure standards represent the airborne concentration of a particular substance or mixture that must not be exceeded. There are three types of exposure standard:
· 8-hour time-weighted average
· peak limitation
· short term exposure limit.
Exposure standards are based on the airborne concentrations of individual substances that, according to current knowledge, should neither impair the health of, nor cause undue discomfort to, nearly all workers. They do not represent a fine dividing line between a healthy and unhealthy work environment.
Chemicals with workplace exposure standards are listed in the Workplace Exposure Standards
for Airborne Contaminants. These exposure standards are also available from the Hazardous Substances Information System (HSIS) on the Safe Work Australia website. The HSIS database contains additional information and guidance for many substances. Although exposure standards may also be listed in Section 8 of the SDS, you should always check the Workplace Exposure Standards for Airborne Contaminants or HSIS to be certain.Guidance on interpreting exposure standards is available in the Guidance on the Interpretation
of Workplace Exposure Standards for Airborne Contaminants.To comply with the WHS Regulations, monitoring of workplace contaminant levels for chemicals with exposure standards may need to be carried out.
1.6 Preparing a register and manifest of hazardous chemicals
Register of hazardous chemicals
Regulation 346: A person conducting a business or undertaking must ensure that a register of hazardous chemicals at the workplace is prepared and kept up-to-date. The register must be readily accessible to workers involved in using, handling or storing hazardous chemicals and to anyone else who is likely to be affected by a hazardous chemical at the workplace.
The register is a list of the product names of all hazardous chemicals used, handled or stored at the workplace accompanied by the current SDS (one that is not more than five years old) for each hazardous chemical listed. It must be updated as new hazardous chemicals are introduced to the workplace or when the use of a particular hazardous chemical is discontinued.
Manifest of Schedule 11 hazardous chemicals
Regulation 347: A person conducting a business or undertaking at a workplace must prepare a manifest of Schedule 11 hazardous chemicals at the workplace.
A manifest is different from a register. A manifest is a written summary of specific types of hazardous chemicals with physicochemical hazards and acute toxicity that are used, handled
or stored at a workplace. A manifest is only required where the quantities of those hazardous chemicals exceed prescribed threshold amounts. It contains more detailed information than
a register of hazardous chemicals as its primary purpose is to provide the emergency services organisations with information on the quantity, classification and location of hazardous chemicals at the workplace. It also contains information such as site plans and emergency contact details.The manifest must comply with the requirements of Schedule 12 of the WHS Regulations and
it must be updated as soon as practicable after any change to the amount or types of chemicals being used, stored, handled or generated at the workplace.A manifest quantity is the quantity referred to in Schedule 11 of the WHS Regulations, table 11.1, column 5 for that hazardous chemical (reproduced in Appendix D of this Code).
2. IDENTIFYING HAZARDS
2.1 How to identify which chemicals are hazardous
The first step in managing risks involves identifying all the chemicals that are used, handled, stored or generated at your workplace in consultation with workers. The identity of chemicals in the workplace can usually be determined by looking at the label and the SDS, and reading what ingredients are in each chemical or product. In some cases, a chemical may not have a label or an SDS, for example where fumes are generated in the workplace from an activity such as welding.
A manufacturer or importer must determine the hazards of a chemical against specified criteria. This process is known as classification, and it is the hazard classification of a chemical that determines what information must be included on labels and SDS, including the type of label elements, hazard statements and pictograms. Manufacturers and importers are required to provide labels and SDS, and must review the information on them at least once every five years or whenever necessary to ensure the information contained in the SDS is correct, for example, new information on a chemical may lead to a change in its hazard classification. Specific guidance on what a manufacturer or importer must include in an SDS and label can be found in:
· Code of Practice: Preparation of Safety Data Sheets for Hazardous Chemicals.
· Code of Practice: Labelling of Workplace Hazardous Chemicals.
You should always read the label in conjunction with the SDS to make sure all chemical hazards are identified. In other cases, product specification sheets may provide information of the types of hazardous chemicals generated during a process, or by researching other sources such as codes of practice or guidance documents on the process.
The manufacturer, importer or supplier may also provide further information about the hazardous chemical. Information on chemicals can also be found in the Hazardous Substances Information System (HSIS) database.
Hazardous chemicals that are contained in plant forming part of a manufacturing process, such as a piping system, must also be identified. This to ensure controls can be implemented in the event of an accidental rupture or spill or when maintenance or cleaning is required.
Hazardous chemicals generated or manufactured in the workplace
Some processes will produce hazardous chemicals as by-products or waste. These hazards may not be easily identified when generated at the workplace, for example hydrogen sulphide in a sewer or diesel exhaust fume from truck engines. Information on by-products may be available from a SDS, but not always. You should find out what hazardous chemicals may be produced from work activities, for example: use of welding rods may liberate toxic fumes and vapours, grinding metals release toxic metal dust or fumes, off-gassing of solvent vapours from glues used to manufacture timber products such as Medium Density Fibre (MDF), and dusts released from machining timbers are hazardous to health or can present a dust explosion risk.
If you produce or generate hazardous chemicals in the workplace, you must manage the risks associated with those chemicals
Once you have identified which chemicals are hazardous, you must prepare, maintain and keep
a register of hazardous chemicals at the workplace, and a manifest if any Schedule 11 hazardous chemicals are above the prescribed limits (see Section 1.6 of this Code)2.2 Safety Data Sheets (SDS)
Regulation 330: The manufacturer or importer must prepare a safety data sheet for the hazardous chemical before first manufacturing or importing the hazardous chemical or as soon as practicable after the first manufacturing or importing and before first supplying it to a workplace.
The manufacturer or importer of the hazardous chemical must provide the current safety data sheet for the hazardous chemical to any person, if the person:
· is likely to be affected by the hazardous chemical, and
· asks for the safety data sheet.
Regulation 339: The supplier must provide the current safety data sheet for the hazardous chemical when the chemical is first supplied to the workplace and if the SDS is amended, when the hazardous chemical is first supplied to the workplace after the SDS is amended
Regulation 344: A person conducting a business or undertaking must obtain the safety data sheet (and any amended version) for a hazardous chemical from the manufacturer, importer or supplier no later than when the chemical is first supplied at the workplace or as soon as practicable after it is first supplied but before it is used at the workplace.
The SDS contains information on the identity of the product and any hazardous ingredients, potential health effects, toxicological properties, physical hazards, safe use, handling and storage, emergency procedures, and disposal requirements specific to the chemical.
If the SDS for a hazardous chemical is not supplied, you must contact either the manufacturer, importer or supplier to obtain one before the chemical is used at the workplace.
Important hazard information to note from the SDS includes:
Hazard classification
This information will be present on the SDS in the form of hazard statements, for example “may cause cancer” or “flammable liquid”.
The route of entry
This information is important as it lets you assess the health risks to your workers. Routes of entry can include inhalation (breathing it in), skin contact, ingestion (swallowing it), eye contact and injection through high pressure equipment.
Depending on the substance, the severity of the harm could range
from minor to major, for example, from minor skin irritation to chronic respiratory disease. Some chemicals may not be hazardous by all routes of entry. For example, silica is hazardous only by inhalation
so the risk assessment needs to consider how inhalation could occur
in the workplace.Advice or warnings for at-risk workers
The SDS may also include summaries of toxicological data, or advice
or warnings for people that might be at risk, such as· people who are sensitised to particular chemicals
· warnings for pregnant women
· people with existing medical conditions such as asthma.
Instructions on storage
This may include advice on not to store with certain incompatible materials, or advice on potential hazardous degradation products.
Examples include – storage of acids and bases, or storage instructions to avoid formation of explosive peroxides in ether during extended storage
Physicochemical properties
Physicochemical properties can have a significant effect on the hazard. Some key properties to note include:
· physical state: is it solid, liquid or gas?
- if solid – what is the potential for dust explosion?
- if liquid – is it mobile/viscous/volatile/miscible?
- if gas (and vapours) – is it lighter/heavier than air?
· flashpoint, fire point and explosive limits
· viscosity
· density
· particle size
· vapour pressure
· solubility and pH
· reactivity
· boiling and/or freezing point or range
· electrical and/or heat conductivity
· the nature and concentration of combustion products.
Use situations that may generate hazardous chemicals
Examples may include:
· use of welding rods which may liberate hazardous fumes and vapours
· directions for use of chlorine bleach, warning that harmful levels of chlorine gas may be generated if the substance is mixed with incompatible chemicals
· warnings that some metals, including alkali metals, in contact with water or acids, liberate flammable gas
· information on by-products or breakdown products like formation of explosive peroxides in ether
Environmental hazards
The SDS should contain information on environmental hazards and risks. An awareness of this information will assist you to meet any environmental laws in your state or territory.
Chemicals which are generally for domestic use and considered safe in the home may present greater risks in the workplace depending on the manner and quantities in which they are used. This is particularly relevant, for example, where domestic cleaning chemicals are purchased from
a supermarket and used in a workplace environment. You should always follow label directions. However, if you are using a domestic chemical in a manner different to normal household use, you should also obtain the SDS in order to determine the level of risks to workers and the appropriate controls. The SDS should contain more detailed information on hazards and risks, for example on incompatibilities with other chemicals and risks from use in enclosed areas.Providing access to SDS in the workplace
Regulation 344: A person conducting a business or undertaking must ensure the current SDS is readily accessible to workers who use the hazardous chemical at the workplace and an emergency service worker, or anyone else, who is likely to be exposed to the hazardous chemical
The SDS should be kept in a location near the work area where the substance is used. You must ensure that all workers likely to be exposed to the hazardous chemical know how to find the SDS. In some cases it may be practicable to provide workers with access to SDS via an electronic database, for example in universities where potentially thousands of chemicals may be used, stored or handled at the site. However, the electronic database should be readily available to workers, workers should know how to use it, and a backup means of providing the SDS should also be provided, for example as hard copies in a filing system.
2.3 Labels
Regulation 335: The manufacturer and importer of a hazardous chemical must ensure it is correctly labelled as soon as practicable after manufacturing or importing the hazardous chemical.
Regulation 338: The supplier of a hazardous chemical must not supply the chemical to another workplace if they know or ought reasonably to know that the hazardous chemical is not correctly labelled.
Regulation 341-343: A person conducting a business or undertaking at a workplace must ensure that the hazardous chemical, the container of a hazardous chemical or a hazardous chemical in pipe work is correctly labelled.
Hazard information will also be available from the label. Some product labels do not contain all hazard information, for example, some consumer product labels, some agricultural and veterinary chemical products where the label is too small to fit all relevant hazard information, or when hazardous chemicals that are dangerous goods are labelled to meet transport requirements.
The SDS should be referred to when reading a label to ensure all chemical hazards are identified.Table 1 below shows examples of elements on a label that indicates the type of hazard and the severity of the hazard.
Table 1 Examples of hazard information on a label
Label element
Examples
Signal words – these provide an immediate warning to the reader
Danger or Warning
Hazard statements – these describe the nature and severity of the chemical hazard based on a chemical’s classification
May cause cancer
Fatal if inhaled
Flammable liquid and vapour
Causes severe skin burns and eye damage
May cause respiratory irritation
Pictograms – these provide a pictorial representation of the type of hazard that can be easily recognised at a glance
Flammable Acute toxicity Warning
Human health Corrosive
Incorrectly labelled or unlabelled containers
If you find a container that does not have a label or is incorrectly labelled, action must be taken to correctly label the container. Containers that have had chemicals transferred into them (decanted) in the workplace, and containers of chemical wastes need to be labelled correctly.
If the contents of the container are not known, this should be clearly marked on the container,
for example, 'Caution - do not use: unknown substance'. Such a container should be stored in isolation until its contents can be identified and, if it is then found to be hazardous, the container
is appropriately labelled. If the contents cannot be identified, they should be disposed of in accordance with relevant local waste management requirements.2.4 Other sources of information
Additional information regarding hazards and risks associated with the use, handling, generation and storage of hazardous chemicals can be obtained from the following sources:
· incident records
· previous risk assessments
· Australian Code for the Transport of Dangerous Goods by Road and Rail
· European Chemical Substances Information System (ESIS)
· The Standard for the Uniform Scheduling of Medicines and Poisons (SUSMP)
· National Industrial Chemical Notification and Assessment Scheme (NICNAS)
· regulatory authorities
· trade unions and employer associations
· work health and safety consultants
· internet searches of authoritative websites, such as those of international work health
and safety agencies like the US Occupational Safety and Health Administration, or the European Commission Joint Research Centre’s Institute for Health and Consumer Protection.3. ASSESSING RISKS
A risk assessment is not mandatory for hazardous chemicals under the WHS Regulations, though it is required for specific situations, for example when working with asbestos. However, in many circumstances it will be the best way to determine the measures that should be implemented to control risks. It will help to:
· identify which workers are at risk of exposure
· determine what sources and processes are causing that risk
· identify if and what kind of control measures should be implemented
· check the effectiveness of existing control measures.
Where the hazards and associated risks are well-known and have well established and accepted control measures, it may not be necessary to undertake a risk assessment, for example, where there are a small number of chemicals in a workplace and the hazards and risks are well understood.
Your risk assessment should also consider foreseeable failures of plant and equipment, as well as any control measures, for example:
· A power failure may impact on the operation of a mechanical ventilation system at the workplace.
· Accidental spills have the potential to corrode or impact on nearby plant or equipment.
Documenting risk assessments is not mandatory, but may help when reviewing where improvements can be made and risks controlled more effectively.
Appendix F and Appendix G provide an overview and checklist of the risk assessment process.
3.1 Decide who should do the assessment
Assessments are based on a thorough understanding of what happens, or might happen, in the workplace and should be carried out by a person or persons who have:
· a practical understanding of the WHS Regulations, codes of practice and relevant guidance materials
· an understanding of the work processes involved at the workplace
· enough resources to gather information, consult the appropriate people, review existing records and examine the workplace.
The person or persons should also have abilities to:
· interpret the information on the label and SDS of the hazardous chemical
· observe the conditions of work and to foresee potential problems
· communicate effectively and consult with workers, contract workers, managers and technical specialists
· draw all the information together in a systematic way to form valid conclusions about exposures and risks
· accurately report the findings to all parties concerned.
A single person such as a supervisor may be suitably competent to perform simple assessments. In more complex cases, several persons representing a variety of skills may need to be involved in collecting and assessing the information. This may also include workers and their health and safety representatives.
Seeking external assistance
In some cases, it may be necessary to seek external professional assistance to assist or undertake risk assessments. External assistance may be required to:
· design an air monitoring strategy
· collect and analyse samples
· interpret monitoring and testing results.
External professional assistance may also be required in the design, installation and maintenance of control measures, such as ventilation systems or fire protection systems.
3.2 Decide what sort of risk assessment is appropriate
The type of risk assessment that should be conducted will depend on the nature of the work being performed.
a) A basic assessment consists of:
· reviewing the label and the SDS of the hazardous chemicals and assessing the risks involved in their use
· deciding whether the hazardous chemicals in the workplace are already controlled with existing control measures, as recommended in the SDS or other reliable sources, or whether further control measures are needed.
For example, the SDS and label report that a cleaning agent may have potential skin irritation effects and may liberate a toxic gas when in contact with certain other chemicals, while in itself it is non-volatile. The assessment indicates that workers who handle this chemical will require control measures, including the use of protective clothing and gloves and that the chemical must be kept away from incompatible materials. Without such an assessment, skin irritation
or intoxication by toxic gas when handling the cleaning agent could have occurred.b) In a generic assessment, an assessment is made of a particular workplace, area, job or task and the assessment is then applied to similar work activities that involve the use of the chemical being assessed.
For example, a business or industry association might do a generic assessment for a number of workplaces that use, handle, generate or store identical chemicals (such as service stations or dry cleaners). When conducting a generic assessment, it is important that the workplace, tasks and hazardous chemicals being assessed are identical in characteristics, properties, potential hazards and risks. Generic assessments are not appropriate for very high risk chemicals such as carcinogens.
c) A detailed assessment may be needed when there is a significant risk to health and for very high risk chemicals such as carcinogens, mutagens, reproductive toxicants or sensitisation agents in the case of health hazards. Information on the label and SDS will allow you to determine whether the chemical has these hazards. Schedule 10 of the WHS Regulations provides further information on the hazardous chemicals that are restricted or prohibited for use (see Appendix C of this Code). A more detailed assessment may also be required when there is uncertainty as to the risk of exposure or health.
In order to complete a detailed assessment, further information may be sought and decisions taken to:
· eliminate the uncertainty of any risks
· select appropriate control measures
· ensure that control measures are properly used and maintained, and
· determine if air monitoring or health monitoring are required.
It may be necessary to engage external professional assistance to undertake a more detailed assessment.
Structuring risk assessments
Risk assessments can be simplified by evaluating the nature of the work in smaller, more manageable parts. You do not need to do a risk assessment covering each work activity in the whole workplace. Instead, evaluate the nature of the work by:
· Dividing up the workplace - If it is not practicable for the workplace to be assessed as a whole, divide it into smaller units (locations/areas or processes) to make risk assessment more manageable. Walking through the workplace and looking at floor plans or process plans will help you decide how to divide up the workplace.
· Grouping similar work - Workers performing similar work or using similar substances
may be grouped together if it has been established that their exposures are representative
of their group. These are referred to as similarly exposed groups. In this way, you can avoid having to repeat exposure assessments for each and every worker.If the work involves a large number of different hazardous chemicals, they may be grouped on the basis of their form, properties and the way they are used or handled. This kind of grouping may be appropriate for example, where:
oa range of solvent-based paints containing a number of different solvents and additives are used in the same or similar way (for example, sprayed, brushed or applied with a roller)
osolvent-based liquid pesticides are used in the same or similar way (for example, decanted, mixed or sprayed)
· Examining work practices and conditions - Once you have divided the workplace into manageable units, you should observe and consult with workers to find out how the job
is actually done. Workers may sometimes not adhere strictly to standard operating procedures for certain tasks. This could be because they have devised a more efficient and/or safer method for performing that task, or because the control measures or PPE provided make
it cumbersome and difficult. Workers should be encouraged to share their views and concerns on working practices and be involved in discussions on how to improve working methods.
Also, it is good practice to find out what changes in workplace activities occur during cleaning, maintenance, breakdowns and during staff absences or shortages.You should take account of any information about incidents, fires, spills, illnesses or diseases that may be related to the use of the hazardous chemical. Check your accident/incident records. Ask those doing the work if they have experienced symptoms listed on the SDS.
This information will help you to determine if exposure has been significant.Considering both health and physicochemical risks
Hazardous chemicals may present an immediate or long term risk to human health through their toxicological properties, or a risk to safety of persons and property as a result of their physicochemical hazards. In some cases, chemicals may present both health and physicochemical hazards, for example solvents such as benzene, toluene and xylene.
There are many common elements to assessing risks from health and physicochemical hazards, but also several key differences in the way these risks are assessed. As a consequence, the assessment of health and physicochemical risks are discussed separately in this chapter.
3.3 Things to consider in assessing health risks
The assessment of health risks from hazardous chemicals involves gaining an understanding of the situations where people can be exposed to, or come into contact with the chemicals, including the extent of exposure and how often this can occur. Health risk depends on hazard severity and level of exposure, and thus depends on both the type of chemical and also the nature of the work itself.
As with all risk assessments, the assessment involving chemical hazards needs to consider all workers potentially at risk, including those not directly involved in a work activity, as well as other people such as visitors to the workplace.
The routes of entry by which the chemical can affect your health
The type of hazard (for example, hazard classifications of carcinogenicity, sensitisation, acute toxicity) and relevant routes of exposure (for example, inhalation, ingestion, skin contact) should be known from the hazard identification step. These are needed in the risk assessment to understand the level of risk from likely or potential exposure scenarios in your workplace.
For particulates in air, the primary health concern is effects on the lungs due to inhalation exposure. For example, crystalline silica is considered hazardous principally because of the long term, irreversible lung effects (such as silicosis), that may arise from prolonged or repeated exposure to excessive concentrations. Its hazardous properties are associated with inhalation,
so the evaluation of risk should be based on the potential for breathing in the crystalline silica
dust rather than other routes of exposure (for example, contact with the skin). In the case of crystalline silica, it is the respirable fraction of the dust that presents the greatest risk to workers
as this fraction contains the smallest particles which can reach further into the lungs causing the most damage.In contrast, even brief exposures to high concentrations of sodium hydroxide may lead to immediate effects which include irritation and burning of the skin, eyes and respiratory tract
and blindness. Its hazardous properties relate to exposure via skin or eye contact and inhalation. Evaluation of risks to health for sodium hydroxide (caustic soda) should therefore consider the potential exposure through all of these routes.Some chemicals may exhibit ototoxic effects. That is, they may cause hearing loss or exacerbate the effects of noise. Evaluating the use of these chemicals should be carried out in conjunction with the Code of Practice: Managing Noise and Preventing Hearing Loss at Work.
The physical form and concentration
Some substances may be virtually harmless in some forms (such as a block of metal, a piece
of wood or granulated solid chemicals) but may be very hazardous in another form (such as fine dust particles or fume that can be readily inhaled or solutions that may be splashed and readily absorbed through skin). This is also an important consideration in assessing risks from physicochemical hazards.The concentration of hazardous ingredients is also an important factor in the overall risk. Concentrates or pure substances may be extremely hazardous, while dilute solutions of the same chemical may not be hazardous at all.
The chemical and physical properties of the substance
Gases or liquids with low boiling points or high vapour pressures can give rise to high airborne concentrations in most circumstances, whereas high boiling point liquids such as oils are only likely to create a hazardous airborne concentration if they are heated or sprayed. Chemicals with a very low or high pH (for instance, acids and caustics respectively) are corrosive to the skin and eyes.
Some substances give off distinctive odours which can alert workers to the presence of a hazardous chemical. For example, hydrogen cyanide has a smell of bitter almonds. However, not everyone can smell hydrogen cyanide and higher concentrations of hydrogen cyanide can also overload nasal receptors resulting in workers being unable to detect it. Hazardous chemicals can also have no odour. Thus, odour should not be relied on as a means of detecting the presence
of hazardous chemical.The chemical and physical properties are also important in assessing risks from physicochemical hazards, described later in this chapter.
Determining who could be exposed, and when this could occur
Workers can come in contact with a hazardous chemical and any waste, intermediate or product generated from the use of the substance if they:
· work with it directly
· are in the vicinity of where it is used or likely to be generated
· enter an enclosed space where it might be present
· disturb deposits of the substance on surfaces (for example, during cleaning) and make them airborne
· come into contact with contaminated surfaces.
You should consider all people at the workplace, including those who may not be directly involved in using, handling, storing or generating a hazardous chemical, such as:
· ancillary or support/services workers (be aware that cleaners, maintenance and laboratory staff are often exposed to both the hazardous chemicals they use in the course of their work, such as cleaning products, and the hazardous chemicals used in the workplace by other workers)
· contractors
· visitors
· supervisors and managers.
You should consider:
· how specific tasks or processes are actually carried out in the workplace (for example, decanting, spraying, heating). By observing and consulting workers you can find out if they are not adhering strictly to standard procedures or if procedures are not adequately providing protection to workers.
· the quantity of the chemicals being used. Use of larger quantities could result in greater potential for exposure
· the risk controls in place and their effectiveness. For example, a ventilation system may
be in use but when poorly designed, installed or maintained it may not achieve the correct level of protection (such as if filters are not regularly cleaned),· whether each worker’s work technique has a significant bearing on their level of exposure – poor techniques can lead to greater exposure
· workers who may be working alone with hazardous chemicals and if any additional precautions or checks may be necessary in case they become incapacitated.
How often is exposure likely to occur and for how long?
The total dose (amount) of a hazardous chemical a worker is likely to receive increases with an increase in the duration or frequency of exposure. Estimations of the duration and frequency of exposure can be based on observation, knowledge and experience of the work. Seek information from your workers and their health and safety representatives to find out:
· Which work activities involve routine and frequent exposure to hazardous chemicals
(for example, daily exposure, including during end of shift cleaning) and who are the people performing these activities?· What happens when non-routine work, production of one-off items or isolated batches, trials, maintenance or repair operations are performed?
· What happens when there are changes to work practices in events such as cleaning, breakdowns, changes in volume of production, adverse weather conditions?
· Are there differences between workers within a group? Anyone whose work habits or personal hygiene (for example, washing before eating, drinking or smoking) are significantly different should be considered separately.
What is the estimated exposure to hazardous chemical?
Once you have investigated the hazardous chemicals, the quantities used, the frequency and duration of exposure, the effectiveness of the controls already in place, and whether workers
are working directly with the substance this information should then be used to estimate the level
of exposure.Inhalation exposure can be determined by personal sampling. Information on the level of airborne concentrations of chemicals can also be obtained from static area sampling, however this method is not acceptable for determining compliance with exposure standards.
Air monitoring should be carried out by a person such as an occupational hygienist with skills
to carry out the monitoring according to the appropriate standard and to interpret the results. Results from air monitoring indicate how effective your workplace controls are, for example whether ventilation systems are operating as intended. Records of air monitoring for airborne contaminants with exposure standards must be kept for a minimum of 30 years, and must be available to workers who are exposed.An estimation of the amount of exposure to hazardous chemicals can sometimes be obtained by observation. For example, you might look for evidence of fine deposits on people and surfaces,
or the presence of dusts, mists or fumes visible in the air (for example, in light beams) or the presence of odours.An indication of the airborne concentrations of hazardous chemicals can often be obtained by simple tests, such as indicator tubes or dust lamps. However, in most cases the amount of exposure may vary throughout the day, so such tests may not establish workers’ exposure with confidence and it will be necessary to undertake detailed air monitoring. For chemicals that present a very high hazard, such as carcinogens, mutagens and reproductive toxicants, you
should consider undertaking air monitoring to determine the level of exposure.Complying with exposure standards
As described in Section 1.5 of this Code, you must ensure that no person at the workplace
is exposed to a substance or mixture in an airborne concentration that exceeds the exposure standard for the substance or mixture. Air monitoring may be necessary to ensure that workers
are not exposed to airborne concentrations above the chemical’s exposure standard.Some chemicals with exposure standards can also be absorbed through the skin – these are given a notation of ‘Sk’ in the publication Workplace Exposure Standards for Airborne Contaminants.
Biological monitoring may be a helpful means of assessing a workers’ overall exposure to a hazardous chemical that can be absorbed through the skin as well as inhaled.
Where results of monitoring show concentrations of airborne contaminants approaching or exceeding the exposure standard, you should review your control measures. Even if monitoring indicates that exposure is below an exposure standard, sensitive workers may still be at risk. Exposure standards do not represent a ‘no-effect’ level which makes exposure at that level safe
for all workers, therefore you should ensure that exposure to any hazardous chemical is kept as low reasonably practicable. This includes exposure to hazardous chemicals that do not have exposure standards.Some chemicals, such as isocyanates, are known to be sensitisers and can induce an adverse reaction in workers at levels well below the exposure standard once sensitisation has occurred.
If a worker becomes sensitised to a chemical, the exposure standard for that chemical is no longer relevant and control measures such as improving engineering controls or job rotation to remove the affected worker from potential exposure to the chemical should be implemented.For more information on how to interpret exposure standards and comply with the WHS Regulations, refer to Safe Work Australia’s Workplace Exposure Standards for Airborne Contaminants and Guidance on the Interpretation of Workplace Exposure Standards for
Airborne Contaminants.
3.4 How to assess physicochemical risks
The assessment of physicochemical risks in the workplace is different in many respects from that needed when assessing health risks. Whereas health risks arise from interaction of people with the chemical, physicochemical risks arise mainly from hazardous chemicals where they come into contact with other things such as ignition sources.
Fire and explosion
Regulation 51-52: A person conducting a business or undertaking must manage the risk to health and safety associated with a hazardous atmosphere or an ignition source in a hazardous atmosphere at the workplace.
Fire and explosion can result in catastrophic consequences, causing serious injuries or death of workers, as well as significant damage to property. They occur when the following three primary elements come together (commonly referred to as the fire triangle – see Figure 1):
· a source of fuel (a flammable or combustible substance)
· a source of oxygen (usually in the air)
· an ignition source (a source of energy sufficient to cause ignition).
Figure 1 Fire triangle
When identifying hazards you should have identified all of the sources of fuel in your workplace that could contribute to fire and explosion risks. Fuels that present the highest risk are those hazardous chemicals that are flammable (for example, flammable solids, liquids or gases, including their vapours and fumes), other fire risk substances in other hazard classes (for example, pyrophoric liquids and solids that ignite spontaneously in contact with air, substances that react with water to emit flammable gasses) and other materials that are not hazardous chemicals, like wood, paper and leaves, and other combustible materials that contribute to the fire load.
You should also identify sources of oxygen, such as oxygen gas and compressed air in cylinders, chemical oxidisers and peroxides. Oxygen is always present in the air. A list of common fuel and oxygen sources are listed in Appendix H.
Note: Chemical reactions and other processes which generate gases can also cause explosions through an increase in the pressure in the container in which the chemical is stored if the gas cannot escape, even if that gas does not itself ignite.
Identifying ignition sources
Ignition sources can be any energy source that has the potential to ignite a fuel. They can be categorised into three broad types: flames, sparks and heat. Some common examples of ignition sources are provided in Table 2.
Table 2 Common examples of ignition sources
Type of ignition
source
Examples
Flames
· Welding flames, gas heaters, pilot lights
Sparks
· Welding arcs, starters for fluorescent lighting, electric motors, electrical equipment like power points, cigarette lighters, switches and telephones
· Static electricity including from friction sources
· Lightning
· Friction from drilling, grinding, scraping of metal on concrete
Heat
· Hot surfaces including light bulbs, ovens, radiators or heaters, flue pipes, vehicle engines and exhaust systems, pumps and generators
· Exothermic chemical reactions (those which generate heat)
Some electrical equipment may also be a source of ignition. However, not all electrical equipment is an ignition source if it is specifically designed so that it does not create sparks. This type of equipment is referred to as “intrinsically safe”
You must identify any ignition source in your workplace that has the potential to ignite a flammable or combustible material. You should also consider sources of ignition that are adjacent to your workplace or may periodically come into your workplace, for example vehicles (with hot engine
and exhaust systems) making deliveries, visitors or other portable items like cordless power tools, radios and fans.Other factors affecting fire and explosion risks
The following physical and chemical characteristics of materials can influence the level of risk
of a fire or explosion occurring.Form and physical state
The form or physical state of chemicals, substances or other materials can have a significant influence on the level of risk of a fire or explosion. The physical state of a material is generally considered as either solid, liquid or gas, however materials can be further categorised as aerosolised droplets, vapours, fumes, mists, powders, dusts or fibres.
Bulk materials in solid, liquid and gas forms behave differently and present different risks. Liquids spread readily compared to solids and have a greater risk of coming into contact with an ignition source if spilled. Gases present a greater risk as concentrations in air are generally higher than
for liquids (and their vapours) and can spread more rapidly. Depending on the vapour density, some gases can flow across surfaces in a similar way to liquids, rather than dissipating quickly.
For example, vapours which have a density greater than air can move along the floor and spread to adjacent work areas where ignition sources may be present, thereby creating a significant risk
in those areas.Temperature and pressure
Changes in temperature and pressure can affect the properties of a chemical.
The explosive range of a chemical (for instance, its lower and upper explosive limits) can change with temperature. At higher temperatures, the lower explosive limit is usually lower, meaning that the substance is more likely to ignite at lower concentrations in air. Heating solid or liquid combustible substances can also increase the vapour pressure (for instance, the concentration
of vapours emitted) of the substance making it more likely to ignite.Handling chemicals under pressure increases the risk in several ways. Any loss of containment will occur more rapidly than under normal atmospheric pressure so that more hazardous chemicals are released. Increasing pressure generally increases temperature of the material, and some chemicals also become unstable at higher temperatures and pressures causing an uncontrolled decomposition or reaction.
Confinement
The effects of an explosion can be exacerbated where the fuel and air mixture is contained, for example in a tank, duct or pipework, as well as in larger structures like silos, rooms or buildings. Explosions can be more violent than when unconfined, and flying debris (such as from the container or building) can cause serious injuries or death.
Fire risks involving chemical oxidisers
Chemical oxidisers can react violently and unexpectedly with many chemicals such as organic material (for example, wood, paper, cellulose products), hydrocarbon solvents (for example, mineral turpentine, petrol, diesel) and other organic (carbon based) chemicals (for example, ethanol, mineral oils).
You should assess any situation where an oxidiser could come into contact with these types of materials. This includes any containers and other equipment used in handling or transferring the chemicals. Oxidisers should be handled in compatible containers and with compatible equipment to avoid a dangerous reaction occurring.
It is important to note that, since oxidisers provide oxygen through the chemical reaction, rather than air being the oxygen source, a risk of fire or explosion can still exist even if these materials are handled under an inert atmosphere like nitrogen.
Fire risks from other chemical reactions
Fires and explosions can occur as a result of chemical reactions. Many chemical reactions are exothermic – that is they give off heat during the reaction. This heat can act as an ignition source igniting any fuels present, pressure can build up in enclosed systems (for example, containers, flasks, pressure vessels) causing the container to rupture or even explode.
You should assess any situation where incompatible chemicals could interact and cause a dangerous or uncontrolled violent reaction.
Dust explosion risks
Dust explosions present a significant risk in some workplaces, however they are often overlooked. Dust explosions usually occur where combustible dusts (or fibres, for example from paper, grain, finely divided organic compounds and metals) have accumulated and are then disturbed and released into the air, coming into contact with an ignition source. Common ways in which dusts can be disturbed include from wind when opening doors or windows, during cleaning or sweeping up of waste or using compressed air to blow out material accumulated in crevices, gaps or in machinery.
Dusts may also be generated transferring materials, such as filling the hold of a ship or a silo with grain (liberating grain dust).
When the dust cloud comes into contact with an ignition source such as a flame, hot surface or spark, ignition can occur causing an explosion. Dust-air mixtures can be classified as hazardous atmospheres in the same way as other flammable materials like vapours from flammable liquids and gases.
Dust clouds can be generated by pressure from an explosion in another area, causing damage and propagation much greater than the original explosion.
Effect of particle size on dust explosion risk
The size of particles in dust can have a significant impact on the explosion risk. Smaller particles have a greater surface to mass ratio and present a greater risk, for example a block of metal such as a metal ingot may be practically inert but could be extremely reactive when in the form of filings or shavings, dust or powder. Similarly, the risk from an aerosol (for instance, fine droplets in air) form of flammable liquid is much greater than for the bulk liquid. Processes that generate fine particles, like grinding and milling of flour and nanomaterials can present significant risks. Special control measures may be needed for handling such materials.
The classification of dust hazardous atmospheres is complex and depends on many factors, including the rate of dust dispersion and sedimentation characteristics, and particle size. Further information is contained in the following Australian Standards:
· AS/NZS 4745: Code of practice for handling combustible dusts
· AS/NZS 60079.10.2: Explosive atmospheres – Classification of areas – Combustible dust atmospheres
Common examples of the types of industries and processes that have a potential for presenting
a fire, explosion or implosion risk are listed in Appendix I.Off-site risks
Some activities, systems of work, structures and equipment that are not directly involved with the use, storage and handling of hazardous chemicals in the workplace may create a hazard that you need to be aware of when undertaking your risk assessment. These include:
· Hazardous chemicals on adjacent or nearby premises that could be ignited by activities at your workplace, and other substances and materials that are not hazardous chemicals but that could add to the overall fire load, such as wooden pallets, paper, combustible liquids
or other combustible materials.· Activities and installations on adjacent premises, such as the operation of plant, equipment and vehicles, deliveries of hazardous chemicals, personnel movements in normal and emergency situations, visitor access and the trial of site emergency procedures.
· The proximity of sensitive facilities which may be put at risk by the presence of hazardous chemicals and during an emergency, such as schools, hospitals, child and aged care facilities, theatres, shopping centres and residences. These may require special consideration when planning for emergencies.
· The presence of incompatible materials, either other chemicals or the materials that plant, equipment, storage and handling systems are made of which could react with the chemicals being stored or handled.
· Foreseeable failures of plant, equipment, storage systems, as well as natural disasters
or extreme weather events such as temperature extremes, wind, lightning or rainfall, including the potential for flooding.· Other failures which could occur and events which may give rise to new hazards or greater risk. Any examination should be systematic, and include consideration of the possibility
of human error in the system’s operation.Risks from corrosive substances
Hazardous chemicals that are corrosive to metals can cause damage to plant and equipment, such as containers, pipes, fixtures and fittings. Corrosion can lead to leaks or complete failure and loss of containment of the chemical, resulting in serious damage to property, exposure of workers to the hazardous chemicals and potential injury and death.
Compressed gases
Compressed and liquefied gases are used as fuel, a source of oxygen or as shielding gases in certain types of welding. The hazards associated with compressed and liquefied gases include fire, explosion, toxicity, asphyxiation, oxidation and uncontrolled release of pressure. Gas leakage is one of the greatest hazards.
Cylinders contain large volumes of gas under high pressure and precautions need to be taken when storing, handling and using cylinders.
Asphyxiation hazards
Asphyxia is a condition that occurs where there is lack of oxygen. This can occur either through:
· consumption of oxygen in the air (burning of fuel, or oxidation process such as microbial activity or rusting)
· an accumulation of gases displacing oxygen in air
· inhalation of the chemical affecting the ability of the body to use oxygen (for example, hydrogen cyanide can asphyxiate a person by binding to haemoglobin in the blood following inhalation).
All gases, including fuel gases (for example, hydrogen, acetylene and liquid petroleum gas)
and inert gases (for example, argon, helium and nitrogen) are an asphyxiation hazard in high concentrations.Too little oxygen in the air that we breathe can cause fatigue and in extreme cases death. Using compressed and liquefied gases can result in dangerously low levels of oxygen. For example, gases that are heavier than air can accumulate in low lying areas such as pits, wells and cellars and gases that are lighter than air can accumulate in high areas such as roof spaces and lofts. Working in an enclosed or confined space with inadequate ventilation, where hazardous vapours can accumulate, is a potential asphyxiation hazard.
You should identify possible causes of asphyxiation in your workplace. In welding and allied processes, asphyxiation can occur from gas slowly leaking in a work area.
Compressed air
Compressed air can be hazardous and should be handled carefully by workers. For example, the sudden release of gas can cause hearing damage or even rupture an eardrum. Compressed air can also deeply penetrate the skin resulting in an air bubble in the blood stream known as an embolism. Even a small quantity of air or other gas in the blood can be fatal.
Ensuring workers are trained to handle compressed air properly can eliminate many of the associated risks. Training and work procedures should emphasise the safe use of air tools and safeguard against the deliberate misuse of compressed air. Also, maintaining air receivers properly prevents the potential for an explosive rupture.
4. CONTROLLING RISKS
4.1 The hierarchy of control
There are a number of ways to control the risks associated with hazardous chemicals. Some control measures are more effective than others. Control measures can be ranked from the highest level of protection and reliability to the lowest. This ranking is known as the hierarchy of control.
You must always aim to eliminate a hazard and associated risk first. If this is not reasonably practicable, the risk must be minimised by using one or more of the following approaches:
· Substitution
· Isolation
· Implementing engineering controls.
If a risk then remains, it must be minimised by implementing administrative controls, so far as is reasonably practicable. Any remaining risk must be minimised with suitable personal protective equipment (PPE).
Administrative control measures and PPE rely on human behaviour and supervision and when used on their own, tend to be the least effective ways of minimising risks.
Eliminating the hazard
This means removing the hazard or hazardous work practice from the workplace. This is the most effective control measure and must always be considered before other control measures.
For example, not using a hazardous chemical or eliminating exposure by:· using nails instead of using chemical based adhesives
· eliminating a handling activity and potential worker exposure by purchasing pre-mixed
or diluted chemicals instead of manually mixing or diluting chemicals at the workplace.Substitution
Substitution is the replacement of a hazardous chemical with a chemical that is less hazardous
and presents lower risks, for example:· substituting a less volatile material to control a vapour hazard may cost less than the installation and maintenance of a mechanical ventilation system
· substituting a highly flammable liquid with one that is less flammable or combustible
· using hazardous chemicals with a single hazard class rather than those with multiple hazards
· substituting high hazard chemicals like carcinogens, mutagen, reproductive toxicants
and sensitisers, with less hazardous chemicals· using diluted acids and alkalis rather than concentrates
· using a product in either paste or pellet form rather than as dust or powder.
Isolation
Isolation involves separating people from the chemicals or hazards by distance or barriers to prevent or minimise exposure. Examples of isolation include:
· Isolate workers from chemicals
ouse of closed systems such as those used during the processing and transfer of flammable liquids in petroleum refineries, or the use of glove boxes or glove bags
oplacing a process, or a part of it, within an enclosure which may also be fitted with exhaust extraction to remove contaminants
oisolating operations in one room with access restricted to properly protected personnel
oplacing operators in a positive pressure cabin that prevents airborne contaminants entering
odistancing workers from hazardous chemicals and any potential hazards generated by their use.
· Isolate chemicals from other chemicals
Hazardous chemicals should be physically separated from any chemicals or other things that may be incompatible. This is achieved by distance, barriers, or a combination of both barriers and distance.
Isolation as a control measure is usually used to control physicochemical risks (for hazardous chemicals that are dangerous goods) because of the greater consequences when incompatible materials interact. However it is also important to consider isolation for other hazardous chemicals. The choice of isolation measure used will depend on a range of factors, including:
othe quantity of hazardous chemicals stored and handled in the work area
othe types of installation involved and the processes applied to the hazardous chemicals in the work area and their associated hazards
oall other activities in the work area which may increase the risks
oany other control measures in place that will minimise the risks.
If possible, separation distances should be applied in a way that would not require additional control measures. If this is not possible, barriers may be required.
When choosing to use a barrier, you should consider:
othe effect that climatic elements may have on a barrier and its effectiveness
othe level of fire resistance provided by the barrier
othe structural capability which may be required to withstand weather, and overpressure resulting from internal or external incidents.
When storing chemicals on shelving or other storage systems, hazardous chemicals should not be stored above or below other chemicals or other things which may be incompatible, potentially interact or contaminate. Hazardous chemicals should never be stored where they could contaminate food, food packaging and other items like personal use products, cosmetics, cigarettes, medication and toiletries.
Unintended dangerous reactions of oxidising agents can be avoided by observing the following precautions:
· keep away from combustible or readily oxidisable materials, including fuel containers, sulfur and powdered metal and any other incompatible materials. Stores of oxidisers should be a reasonable distance away (for example, at least 5 m)
· place packages and containers on clean pallets, racks or shelving to allow easier detection of leaks and to prevent contact with other substances. Some oxidising chemicals can ignite on contact with timber, therefore, old and weathered pallets should not be used
· Eliminate sources of heat if practicable. If this is not practicable, ensure that heat sources do not allow the oxidising agents to be heated to within about 15°C of their decomposition temperature
· keep packages closed when not in use to avoid spillage
· do not park or drive any vehicles (e.g. forklifts) nearby because heat from the engine or fuel or oil leaks may cause a dangerous occurrence
· do not store any liquids above oxidizing agents in case leaks cause incompatible materials to spill onto the oxidising substance
· do not allow accumulation of dust and keep surfaces clean in areas where oxidising substances are handled in the workplace
· clean up spillages immediately and dispose of waste in accordance with your local regulations. Do not mix substances in the waste bin because they might react or cause a fire.
Solid (dry) pool chlorine
If your workplace keeps large quantities of solid (dry) pool chlorine on the premises, avoid dangerous reactions by observing the precautions listed above. You should also ensure that the pool chlorine is kept a safe distance away (e.g. at least 10 m) from any ammonium salt like ammonium sulfate, or be separated from it by suitable bunding.
ORGANIC PEROXIDES (Class 5.2 dangerous goods)
Organic peroxides are capable of self-reaction and stabilizers are usually necessary. Some are classified as “Goods too dangerous to be transported” and extreme caution is needed when storing or handling these materials.
Like oxidising agents, organic peroxides can be highly reactive with incompatible materials and precautions are necessary to avoid unintended reactions occurring. Risks can be eliminated or minimised by observing the following precautions:
· keep packages in a specifically designated and designed cabinet, room or external storage building containing explosion vents and/or doors to limit the effects in the event of an explosion
· keep a suitable safety zone (e.g. 5 m) opposite the cabinet or storeroom doors and blow out panels
· use cabinet doors with friction or magnetic catches to allow any pressure build up
to escape more easily· keep nothing else in the organic peroxides store. If this is not practicable, then measures should be taken to ensure that incompatible materials cannot come into contact with the organic peroxides
· keep the storage area free of waste, dirt, dust or metal filings (these could react with spillages) or any combustible materials
· eliminate ignition sources inside, or outside within a suitable exclusion zone (e.g. 3m) of the storage area or entrance to the store
· keep packages on sealed or laminated hardwood or coated metal shelves free from rust or corrosion to avoid a harmful reaction in the event of a spill
· keep a space of at least 100 mm between the packages and the floor, ceiling, or walls.
Fitting a guarding system or raised shelving can assist with this· keep suitable spill containment equipment close to the store which can be accessed quickly and used in the event of a spillage
· if opening packages, take them at least 3 m clear of the store. Reseal all packages before returning them to the store.
Temperature controls can be important in the safe handling and storage of organic peroxides.
To avoid harmful reactions or decomposition of the organic peroxides due to temperature:· determine any critical temperatures including any recommended maximum temperature.
The label and SDS may provide this information. Otherwise, other sources should be consulted. Keep the store within the recommended temperature range for the different types of organic peroxides present and keep organic peroxides out of direct sunlight· do not permit heating to be installed in the storage area.
If cooling or refrigeration is required to maintain the desired temperature in the storage area, expert advice should be obtained because air conditioners and unmodified refrigerators are potential ignition sources.
Further information on storage and handling of organic peroxides can be obtained from AS 2714: The storage and handling of organic peroxides.
CORROSIVES (Class 8 dangerous goods)
Corrosive substances and mixtures [class 8 dangerous goods] can be either alkaline or acidic and these two categories are incompatible. Acids should never be stored with alkaline chemicals due
to the potential for harmful reactions. Some reactions of acids and alkaline chemicals can be highly exothermic and rapidly generate large amounts of gas, causing an explosion risk.Risks associated with storage and handling of corrosive substances and mixtures can be eliminated or minimised by observing the guidance in the following Australian Standards:
· AS 3780: The storage and handling of corrosive substances
· AS 1940: The storage and handling of flammable and combustible liquids (where the corrosive substance or mixture is also a flammable liquid or has a dangerous goods Subsidiary Risk of Class 3 (flammable liquid)
· AS/NZS 3833: The storage and handling of mixed classes of dangerous goods,
in packages and intermediate bulk containers.Eyewash and safety showers should be readily accessible where corrosives are handled
or transferred.APPENDIX K – CASE STUDIES
A number of examples illustrating the process of risk assessment and control are presented
in this section. They do not cover all the possible hazards, risks and control options for the particular situations described. Their purpose is to demonstrate the different ways in which the process can be carried out, and the steps involved in making decisions – particularly about the
risk and the controls to be put in place. As these case studies show, the complexity of the process depends on the substance(s) used and the nature of the work.Case study 1: Motor vehicle finishing workshop
A spray-painting shop uses isocyanate spray paints and organic solvents for equipment cleaning and paint thinning.
One of the spray-painters reported symptoms of skin rash and light-headedness, which often occur at the end of his shift. The reported symptoms are consistent with exposure to isocyanates. It was decided to assess the processes undertaken at the shop to see if any measures could be taken
to reduce exposure to the chemicals being used.The team at the spray-painting shop were not experienced in carrying out risk assessments
so engaged the services of a professional occupational hygienist.The team assessed the working environment and found significant risk of exposure to isocyanates and organic solvents in the four main tasks carried out at the premises.
· Mixing: This manual operation is performed in a segregated area with no mechanical ventilation. According to the SDS, most of the isocyanate present in the paint hardener (HDI) was present in a relatively non-volatile pre-reacted form (a “pre-polymer”) and the concentration of the more volatile non-polymerised form was less than 0.4 %. Given the nature of the task, inhalation exposure to HDI vapour or aerosol during mixing was low. However, there remained a significant risk to health due to potential skin exposure because gloves are not generally worn. The mixing takes around 15 minutes to complete and is performed as required.
· Colour matching: This is carried out in the same area as the mixing and involves spraying
a test panel until the required colour is achieved. It was concluded that there is a significant risk of short-term inhalation exposure to isocyanate-containing aerosol and vapour because respiratory equipment is not routinely worn for this task and there is no ventilation. There
is also a risk to health through skin exposure to isocyanates because suitable PPE is not generally worn. The colour matching takes approximately five minutes and is undertaken
no more than twice in any given day.· Spray painting: A brand-name two pack paint system is used for spray painting vehicles. This is carried out in a ventilated down-flow booth that complied with AS/NZS 4114: Spray painting booths – Design, construction and testing but had not been maintained properly
for some years. The spray painter wears a half-face combined particulate/vapour respirator while performing this task and no other protective equipment other than standard cotton overalls. It was concluded that there was significant inhalation risk to the spray painter
as the respiratory equipment was not suitable for the task. There was also a risk of skin contact because suitable PPE, such as gloves was not worn. The spray painter spends
up to six hours per day spraying.· Cleaning: This task is also carried out in the same area as the mixing and colour matching operations. Used equipment is soaked in an open vessel containing organic solvent. Solvent-soaked rags used for cleaning were placed in an open bin beside the mixing table for disposal. According to the SDS, the solvent is flammable. Equipment cleaning takes around 30 minutes and is performed at the end of the day. The solvent is stored in a flame-proof, lockable cabinet when not in use.
The assessment also considered the potential for a fire or explosion resulting from the use of the flammable solvent. The assessment indicated that the use of solvents was not extensive and only small quantities were kept on the premises at any one time. Solvents are stored in a lockable, flame-proof cabinet. Paints were thinned and mixed when required in a dedicated work area and no ignition sources were present in that area. When used for cleaning of equipment, this was in the same area and had electrical equipment that was rated as intrinsically safe in accordance with the relevant Australian Standards.
The following main actions from the assessment are recommended:
· regular maintenance and testing of ventilation rates and the clearance time of the
spray booth· regular replacement/cleaning of filters in the spray booth
· provision of suitable personal protective equipment including respiratory protection against solvent vapours during spray painting and airborne isocyanates
· regular air monitoring of solvent vapours and isocyanates
· health monitoring (including biological monitoring) for determining isocyanate exposure
be considered· appropriate training of workers.
| TASK | ROUTE OF EXPOSURE | CONTROLS ALREADY IN PLACE? | RISK TO HEALTH? Yes/No/Not Sure | ACTIONS TO BE TAKEN | |
| MIXING | Skin | No specific controls are used | Yes | SDS states that isocyanate and thinning solvent exposure can cause skin irritation. The risk of exposure is high because protective clothing is generally not worn. | Gloves and overalls should be worn as stipulated on SDS |
| Inhalation | No; the area used for this task is not mechanically ventilated | Yes | SDS of pre-polymer indicates only 0.4% content of volatile HDI. Given the nature and duration of the task, the risk of exposure from inhalation is not considered significant. There is risk to health from inhalation from solvents used for thinning paints. | Air monitoring should be considered to assess levels of solvents used for thinning paints. Due to low levels of volatile HDI in paint, the risk is low, however, it may still be worth considering air monitoring for isocyanates too. | |
| Ingestion | No eating, drinking or smoking permitted. | No | Procedures are followed. | N/A | |
| COLOUR MATCHING | Skin | No specific controls are used | Yes | The risk of skin exposure is high because gloves and suitable overalls are not worn for this task. Isocyanates are skin irritants and sensitisers | Gloves and overalls should be worn as per SDS to prevent skin contact. |
| Inhalation | No specific controls are used | Yes | Short-term inhalation exposure of isocyanate aerosol and vapour is high during spraying because no respiratory protection is worn. Exposure standard may be exceeded during this task. Isocyanates are respiratory irritants and sensitisers | This task should be performed wearing an air-fed, full-face respirator to prevent inhalation. Perform task in down flow spray booth. Immediately service down flow booth to ensure it is working as designed and installed. Air monitoring for isocyanates is recommended unless process moved to ventilated area. | |
| Ingestion | No eating, drinking or smoking is permitted | No | Procedures are followed | N/A | |
| SPRAY PAINTING | Skin | No specific controls are used | Yes | The risk of skin contact is high because isocyanate-based paint is sprayed without protective clothing being worn. The respirator only covers half the face of operator so skin on face and head at risk of exposure | Protective gloves and overalls should be worn as per SDS to prevent skin contact. Air-fed, full face respirator should be worn. |
| SPRAY PAINTING (cont.) | Inhalation | A combination particulate/vapour respirator is used. This respirator only covers half of the face. | Yes | This task is performed in a down-flow booth which has not been maintained properly for some years. Furthermore, the respiratory equipment is inadequate; particulate/vapour respirators are not particularly suitable for spray painting. Health effects from inhalation of isocyanates are serious and can be irreversible. The task is long in duration and the exposure standard is very low. This is a high risk activity. | Downflow booth should be immediately serviced and tested to ensure it is working effectively. A regular maintenance program needs to be put into place. Spray painting should be undertaken using a full-face, air-fed respirator. Health monitoring should be considered to ensure controls are adequate. |
| Ingestion | No eating, drinking or smoking is permitted | No | Procedures are followed | N/A | |
| CLEANING | Skin | No specific controls are used | Yes | Gloves and overalls are generally not worn. Although the task is relatively short, the solvent is highly flammable and a skin irritant. The risk of skin exposure is high due to no gloves being used. SDS states that prolonged skin contact with the solvent may lead to dermatitis. | Consider automated spray-gun washing up unit Use gloves and overalls are per SDS |
| Inhalation | No specific controls are used | Yes | The solvent is volatile and represents an inhalation risk. Cleaning is performed in an open vessel and soiled rags stored in an open bin with low ventilation in the room, which can allow solvent vapour to build up. | Install wash-up units fitted with LEV Use respirator fitted with organic vapour cartridge Use a closed vessel to minimise evaporation and perform cleaning in area with better ventilation. Store solvent-soiled rags in a suitable, sealed container prior to disposal. | |
| Ingestion | No eating, drinking or smoking is permitted | No | Procedures are followed | N/A | |
| ARE THERE ANY REPORTED HEALTH EFFECTS?: A spray painter has reported skin irritation and light-headedness after spray painting. These symptoms are consistent with exposure to isocyanates. Immediate action is necessary. |
| PHYSICOCHEMICAL EFFECTS: Flammable solvents are used in the workshop however quantities are small. The solvent being used is highly flammable. It is stored overnight, along with any generated waste, in a lockable, flame-proof cabinet prior to disposal by a local waste company. There have been no reported spillages in the past 12 months and no fires have occurred. Smoking is prohibited and the procedure strictly adhered to and there are no other sources of ignition close to the storage or mixing areas. The equipment in the spraying work area is rated as intrinsically safe. |
| OTHER COMMENTS: The workshop has strong chemical odours. The filters servicing the spray booth should be cleaned and/or replaced at the end of each working day to prevent the build up Spray booth has not been serviced for some time and air flow does not meet AS requirements. It is recommended all spray painters undergo regular health monitoring checks to ensure the integrity of controls in place. A detailed report* is attached (*report not provided for the purpose of this example) |
| ACTIONS ARISING: See above assessment matrix for action in light of the assessed processes. Particular attention should also be paid to the following to ensure that controls maintain their integrity and protect employees · Scheduled testing of the downflow ventilation system · Regular replacement/cleaning of filters in the spray booth · Regular assessment of PPE to check for any signs of wear and tear (refer to manufacturer’s instructions) · Supervision and training of personnel in the use of PPE and other controls · Filters for air supply to be cleaned or changed at regular intervals and according to the manufacturer’s instructions · Regular air monitoring should be considered for operations where employees are exposed to solvent vapour or isocyanates. |
| ASSESSMENT RESULT AND RECOMMENDATIONS BY (person responsible): Occupational Hygiene Consultant Pty Ltd. ACTIONS DUE BY AND RE-INSPECTION DATE: 1 March 2012 |
| APPROVED BY/NAME: General Manager SIGNATURE: DATE: 2/1/2012 ASSESSOR’S SIGNATURE: Occupational Hygiene Consultant Pty Ltd SIGNATURE: DATE: 2/1/2012 |
Case study 2: Vapour Degreasing Operation
Job description
Small metal components are produced on an automated press that uses oil as a lubricant for the cutting tool. The components are collected in a metal basket and then manually transferred into
the solvent vapour-degreasing unit to remove the oil. Trichloroethylene is used as the degreasing solvent. One operator runs the press and the degreasing unit.Information about the chemical classification:
Manufacturer’s SDS and label indicate that trichloroethylene (a volatile solvent) is a hazardous chemical. The oil is not classified as a hazardous chemical.
Health effects for the different routes of exposure:
The SDS indicates that exposure through inhalation can affect the central nervous system and organs such as the liver, lungs and kidneys. Skin and eye irritation can also occur on contact.
Physicochemical hazards of the chemical
Stable at normal conditions, and stable under recommended storage conditions.
Flammability – substance is not flammable. However, it decomposes in a fire giving off toxic fumes: hydrogen chloride gas
Conditions to avoid: Keep away from open flames, hot surfaces and sources of ignition.
Materials to avoid: Incompatible with strong bases and oxidizing agents, alkaline metals / alkaline earth metals.
Exposure standard:
The exposure standard for trichloroethylene is 10 ppm (parts per million) in air averaged over
an 8-hour period. Trichloroethylene also has a short-term exposure limit (STEL) of 40 ppm averaged over a 15 minute period.Controls already in place
Task: normal operation
The degreaser is fitted with a cooling coil to prevent escape of the hot vapour. The baskets are lowered into, and raised out of the degreaser at a pre-set controlled rate (slow speed) using a winch to minimise vapours being dragged out of the unit.
Task: cleaning out the sludge
Before the operator enters the degreaser to clean out the sludge, the solvent is drained out of the unit. A half-face respirator and gloves are worn. This task is carried out approximately three times a year.
Task: storage areas
The chemical is stored away from incompatible materials.
Routes of exposure
Considering the nature of the hazardous chemical and the task during normal operation, the main route of exposure is inhalation. There is very little potential for skin and eye contact during normal operation because of the way the components are handled and the solvent readily evaporates. This would also apply to ingestion.
When cleaning out the sludge at the bottom of the degreaser, there is the potential for significant skin and eye exposure in addition to inhalation.
Evaluation of risk to health
It was determined that there is a risk to health for the following reasons:
· The degreaser is quite old and poorly maintained.
· A very strong solvent odour can be detected in the vicinity of the degreaser, particularly when lifting the basket out. This is because the components trap the condensing solvent vapour. In this case, stacking the components in the basket in a different way would not overcome this problem.
· The operator has reported symptoms of eye irritation and light-headedness.
· The operator would be exposed to a very high level of trichloroethylene vapour whenever the build-up of sludge is cleaned from the bottom of the degreaser. Although this task is only performed occasionally, it requires the operator to get into the degreaser and as such is a ‘confined space entry’ which comes under the WHS (Confined Spaces) Regulations. Exposure to the substance in this confined space poses a serious risk to health (possibly death) particularly through inhalation of trichloroethylene vapour. The personal protective equipment used provides inadequate protection.
Evaluation of risks from physicochemical hazards
Since the chemical is stored away from incompatible materials, the risk of hazardous reactions occurring during storage is minimal.
Controls to be put in place
The sole purpose of the vapour degreasing operation is to remove the fine coating of oil and supply the client with a clean product. Discussion with the client indicated they prefer the components to be coated with oil as it protects against corrosion whilst the components are stored on their premises. Therefore it was decided that the use of trichloroethylene be eliminated.
Case study 3: Cleaning offices
Risk Assessment Report Date: 20 June 2011
Assessor(s):
Management and health and safety representative
Job description:
Products used by cleaners of several office blocks include a disinfectant, a toilet cleaner and a glass cleaner. The toilet and glass cleaners are used as supplied. The disinfectant is diluted with two parts of water and sprayed and wiped onto surfaces. Dilution (mixing) of the disinfectant (Zap) takes place in a central storeroom.
Hazardous chemical:
The SDS for Zap indicated that the product is classified as hazardous. Manufacturers of the other products confirmed that their products were not hazardous according to the WHS Regulations.
Form:
Water based concentrate
Active ingredient:
Sodium hypochlorite (15%)
Health effects:
Skin, eye and respiratory irritant; prolonged
skin contact may cause dermatitis
Routes of exposure:
Skin, eyes and inhalation (particularly spray mist). Exposure through ingestion is not considered to present a risk to health because of the nature of the tasks and the controls in place (see below).
Physicochemical hazards
May decompose above 40°C, in sunlight or in contact with acids. Also reacts with oxidisable materials, heavy metals (which act as catalysts), reducing agents, ammonia solutions, ether, and many organic and inorganic chemicals such as paint, kerosene, paint thinners, shellac, grease and oils. May liberate chlorine gas on decomposition.
Who is exposed:
All cleaners are involved in the mixing and application of Zap.
Frequency and duration of exposure:
Mixing (dilution) is done once at the start of each shift. It takes approximately a minute to perform this task. Workers use the working strength solution for 4 hours a day, 5 days a week.
Controls already in place:
· Cleaners are provided with training on the hazards of using the chemicals, including correct storage locations.
· Cleaners are provided with rubber gloves.
· There is good general ventilation in the storeroom.
· Eating, smoking and drinking is prohibited in the storeroom. Signs to this effect are displayed.
· Washing facilities are available in the storeroom and in the areas where Zap is used.
· Only non-metallic plastic containers are used for mixing and it is stored indoors away from direct sunlight.
Risk Assessment Worksheet
Task
Routes of exposure
Risk to health? (Yes/No/Not sure)
Mixing
Skin/eyes
YES:
• Handling of the concentrate presents the greater risk –particularly to skin and eyes.
• Splashes to the skin and face have occurred occasionally
when decanting concentrate.• Gloves provided are not always worn.
• Goggles or a face shield are not provided.
Inhalation
NO:
• Exposure through inhalation does not present a risk to health due to the short duration of the task.
• Adequate general ventilation.
• Potential for generating fine spray mist during this task is negligible.
Spray and wipe
Skin
YES:
• Gloves provided are not worn very often.
• SDS indicates that prolonged contact even with the diluted substance may cause skin irritation and possibly dermatitis.
Inhalation
YES:
• When working in confined, poorly ventilated areas.
• Fine spray mist generated by spray applicator.
Risk control actions:
· Purchase the concentrate in containers fitted with a dispenser (tap) to minimise the potential
for spills and splashes during decanting. Hang a small plastic container under the tap dispenser to contain any drips. Alternatively, an automatic dilution and dispensing system may be installed to avoid contact with the concentrate.· Use a more dilute working strength solution. The directions for use on the label recommend a concentration of 1-2% for this type of application. Cleaners have been using a more hazardous 5% working strength solution. The reason for this is not known.
· Use a coarse spray applicator to reduce the potential for exposure through inhalation.
· Make further enquiries about alternative products by contacting manufacturers. Consider purchasing a ready-to-use (1-2%) solution of the product to eliminate mixing, or consider
a less hazardous product.· Rubber gloves must still be worn during application of the dilute solution, in order to avoid prolonged contact. Information and training is to be provided on the nature of the hazards,
risks and the need to wear the gloves.Case study 4: Pesticide spraying
Assessor(s): Manager; health and safety representative; spray operator
Hazardous chemical:
Product name: Chlorpyrifos 500 EC
Form: Solvent based concentrate containing 500 grams per litre of Chlorpyrifos in a hydrocarbon solvent
Active ingredient: Chlorpyrifos (an organophosphorus insecticide)
Health effects: Nervous system (cholinesterase inhibition)
Major routes of exposure: Inhalation (spray mist and solvent) and skin absorption (Chlorpyrifos is readily absorbed through intact skin). Chlorpyrifos is an insecticide used on vineyards. Sometimes other liquid organophosphates are also used, following the same mixing and spraying techniques. Therefore this assessment would also cover their use.
500ml of the concentrate is poured (decanted) from a 20 litre drum, into a plastic jug. Before pouring this into the spray tank of a tractor-drawn air blast sprayer, water is added to the tank to dilute the concentrate to a concentration of 0.25 grams per litre (i.e. 2000 times dilution).
The tractor-drawn air blast sprayer can generate a large quantity of fine spray mist.
Chlorpyrifos is sprayed two to three times a week on several vineyards from about October to February.
One operator, who has completed the Farm Chemical Users Course (FCUC), does all the mixing, spraying and the cleaning up of the equipment used.
Others who may be exposed to some Chlorpyrifos are those involved in thinning, pruning or repairing spray equipment. They are not considered to be at risk (refer to report).
Physicochemical hazards: chemical is a flammable liquid category 4 (flash point 68°C).
Job description:
Task
Routes
Controls already in place
Risk to health? Yes/No/Not sure
Action
Mixing
Skin
Gauntlet rubber gloves, PVC apron, gumboots and face shield worn. Measuring jug is rinsed immediately after use. Tap available for washing.
Yes
Spills and splashes have occurred. Chlorpyrifos is very toxic. It is handled in concentrated form. The SDS indicates it is easily absorbed through skin. If protective equipment is not worn or properly maintained there would be a serious risk to health.
Consider ways of eliminating or reducing the use of the pesticide. Consider using a less hazardous pesticide.
Investigate the use of suitable dispensers to minimise spills. A dispenser would mean that less personal protective equipment would be required.
Inhalation
Mixed in well-ventilated area.
No
The SDS indicates that Chlorpyrifos is not very volatile. The solvent is volatile but mixing only takes a few minutes and is done in a well-ventilated area.
Ingestion
No eating, drinking or smoking when handling the pesticide. Washing facilities are provided.
No
Procedures followed. Operator has attended training course. Supervision provided.
Spraying
Skin
No specific controls besides a cotton hat, long sleeve cotton overalls and leather work boots are worn.
Yes
The operator may be exposed to spray drift although the pesticide is not as concentrated as when it is mixed. The airblast sprayer can generate a large quantity of fine spray mist.
Consider the use of a tractor cabin to control the risk.
If the use of a tractor cabin is not practicable, consider application techniques that reduce spray drift.
Inhalation
As above.
Yes
As above.
Ingestion
No eating, drinking or smoking when handling the pesticide. Washing facilities provided.
No
Procedures followed.
Thinning
Pruning
Picking
Skin, Inhalation, Ingestion
Recommended re-entry periods are observed. People doing these jobs also know when the vineyard was sprayed and the pesticide used. Jobs on the vineyard are coordinated so that people not involved in spraying are kept well away from the areas where Chlorpyrifos 500 EC is sprayed. These people are told when spraying is being done and where.
No
Refer to “CONTROLS ALREADY IN PLACE”. Note: where re-entry periods are not given, operators doing these jobs do not enter the orchard for at least 24 hours so that the spray mist has settled.
None. Current controls are adequate. Ensure existing controls are maintained.
Cleaning, service and repair of equipment
Skin, Inhalation, Ingestion
After spraying, the empty tank is rinsed and the nozzles flushed. Where the tank is not empty the remaining contents are disposed of in accordance with label instructions, including use of appropriate PPE.
The spray equipment, including the tractor, is also hosed down. This process is repeated for the tank and the nozzles if the equipment is to be repaired or serviced externally.
No
Yes
Where the spray tank is empty following spraying, the pesticide is further diluted during cleaning and the task is such that there is no likelihood of skin contact with the diluted pesticide/rinsing water.
Where the tank is not empty after spraying, skin contact and inhalation may occur during emptying. Risks are minimised by following label directions and wearing appropriate PPE.
None
Storage and mixing
Fire risks
Storage and mixing operations involving the flammable concentrate are a dedicated work area away from ignition sources and incompatible materials like oxidisers (hypochlorite bleach).
Recommendations in AS 1940: Storage and handling of flammable and combustible liquids have been followed.
Workers are provided with training and advised of the
fire risks.No
Procedures in place and followed including not smoking in storage and mixing areas or while mixing.
None
Notes
1. Organophosphate pesticides such as Chlorpyrifos, are hazardous chemicals for which health monitoring may be required. In this case, health monitoring is likely to be required for workers spraying and mixing the chemical if adequate controls are not used. However if adequate controls are in place and there is no risk to health, health monitoring may not be required. Workers not applying the insecticide, such as thinners, pruners and pickers, would not need health monitoring provided recommended re-entry periods are observed and spraying is not carried out near them when they are working.
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