This blog is a quick guide to the workplace exposure standards for airborne contaminants. It will help you understand your duties under the WHS Act and Regulations to ensure that no-one at your workplace is exposed to an airborne concentration of chemicals that exceeds the Standards. Use this article to support your risk management plan and compliance efforts.
What are chemical exposure standards?
The Workplace Exposure Standards For Airborne Contaminants is an official government document which identifies the maximum levels of airborne exposure of more than 700 hazardous substances and mixtures. In simple terms they define how much of a chemical (eg, vapours, dust) in the air can be breathed by a worker.
Of course there are many thousands of other chemicals that can be hazardous when inhaled which do not have an established exposure standard, so it’s essential to apply a tested risk management methodology when calculating the chemical exposure levels at your workplace.
REMEMBER: Exposure standards do not create a dividing line between safe and unsafe working conditions. You still need to factor individual susceptibilities (eg, allergies, age, fitness, BMI) when assessing chemical exposure risks to your workers and other personnel.
Apply a risk assessment methodology to chemical hazards
The first step in complying with the chemical exposure standards in Australia is to conduct a risk assessment on the chemical hazards at the workplace. Your risk assessment will include identifying each of the chemicals at the worksite; reviewing their Safety Data Sheets (SDSs) to verify any known health hazards; and determining the different ways your workers could be exposed to the chemicals. If any of the chemicals are listed in the exposure standard you will need keep airborne concentration levels inside the limits of the standard.
Looking at the bigger picture, you have a legal obligation under the WHS Regulations to make sure that workers and other people are not exposed to health and safety risks arising from the business, so you need to decide on the best way of eliminating (ideally) or minimising exposure to those chemical hazards. Applying a tested risk management methodology which uses the Hierarchy of Control to determine the most suitable risk control measures is essential to complying with the law.
Even though the Australian workplace exposure standards are a hazard control measure identified in the WHS Regulations, if you use a chemical listed in the exposure standard you should work through the Hierarchy of Control (eliminate, substitute, isolate, engineer, administrate, PPE) before testing chemical exposure levels and introducing any changes into the workplace.
The Hierarchy of Control might identify:
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A way to completely eliminate the chemical from the workplace.
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A less harmful chemical (with no exposure standard) that could be substituted for the chemical currently being used.
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A way of completely isolating the chemical so workers are not exposed.
Your risk management process incorporates the entire organisation and identifies other operating hazards and Dangerous Goods that may increase or decrease the impact of a chemical hazard. It will give you a clearer picture of the way a chemical is being used, workers who are more vulnerable to chemical exposure, other chemical mixtures in the air which may vary exposure levels.
IMPORTANT: Keeping staff within the limits of chemical exposure standards does not automatically guarantee their safety or replace the need to use PPE and wear protective clothing.
Identifying and monitoring chemical exposure levels
Once you have identified the chemicals at the workplace which have an exposure standard and require monitoring there are a number of steps required to achieve compliance:
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Identify acceptable exposure limits - review the exposure standards to determine the: TWA (exposure levels for staff working an average 40 hour week (5 x 8 hour shifts) ; STEL (short term exposure levels (4 x 15 minute blocks each working day); and Peak Limits (exposure levels (up to 15 minutes) that must never be exceeded).
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Measure the existing chemical exposure levels - you may need the assistance of an external consultant (ie, toxicologist, occupational hygienist) who will help you work out an air monitoring strategy that includes the workers and job areas that need surveying (and over what period of time).
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Introduce exposure control measures - these might include: using wet methods to reduce dust; job rotation; diluting substances; wearing respiratory protection.
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Monitoring chemical levels - periodically monitor and test chemical exposure levels to ensure they remain within the standards.
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Monitoring the health of staff - Having staff undergo regular health checks to identify any changes to their health status because of exposure to the chemicals.
IMPORTANT: The Standard (and WHS legislation) has specific requirements for airborne asbestos. Safe Work Australia has a dedicated Code of Practice — How to Safely Remove Asbestos.
Next Steps
Now you have a better understanding of your duty to control chemical exposure at the workplace, why not download our free eBook How to manage the risk of Hazardous Chemicals in the workplace. You’ll learn how to implement a risk management methodology and select the most suitable control measures (including mandatory controls) for each of the chemical hazards identified at your worksite. Download and read it today by clicking on the image below:
