Workplace Exposure Standards

Within Australia, Safe Work Australia is the governing body who researches and assigns exposure standards for various substances used throughout workplaces. These can include, but not limited to, crystalline silica, welding fumes, lead and other chemicals. These exposure standards are called workplace exposure standards (WES) and is defined as the concentration of a particular substance that a worker cannot be exposed above within their breathing zone for an 8 hour day. If an employee works over an 8 hour day (or 38 hour week), WES are usually reduced to compensate for the longer working hours.

Depending upon the hazardous substance, most chemicals are inhaled and impact the lungs, while others include being absorbed through the skin, eyes, or ingested with food or similar. Some chemicals can have a variety of health effects including but not limited to, carcinogenic, ototoxicity (affecting hearing), dermal (skin) rashes (called dermal sensitisers) along with affecting lungs including lung sensitisers. Within the Occupational Health and Safety Regulations 2017, Regulation 165 states that “An employer must ensure that an employee is not exposed to an atmospheric concentration of a hazardous substance supplied to or generated at the workplace above the exposure standard (if any) for the substance or any of its ingredients.” This means that workers who are within environments where there are concentrations of the hazardous substances need to have exposures below the set WES.

Even though there are concentrations set for WES for various hazardous substances, due to factors including but not limited to, physical health, age, previous illnesses or similar, some employees may be affected more so by some hazardous substances even if they are below the WES. Therefore, it is always best practice to keep employees' exposures as low as reasonably practicable using the hierarchy of controls. Depending upon hazardous substance, some chemicals used including lead, cadmium and crystalline silica will also require health monitoring. These can be found within Schedule 9 of the Occupational Health and Safety Regulations 2017.

In order to comply with the above regulation, atmospheric monitoring is conducted by a company who specialises within occupational hygiene monitoring. Atmospheric monitoring is needed, as specified within regulation 166 of the Occupational Health and Safety Regulations 2017 when, “there is uncertainty (based on reasonable grounds) as to whether the exposure standard is being exceeded; or atmospheric monitoring is necessary to determine whether there is a risk to health.” Some of these chemicals where it is necessary include crystalline silica, where atmospheric monitoring is used to help form the basis of crystalline silica hazard control statements. Depending upon the hazardous substance, along with the type of workplace, various control measures can be employed using the hierarchy of controls to best protect employees. Organisations who undertake this work along with recommending control measures can include organisations who specialise in occupational hygiene monitoring, including HAZCON. Usually, a comprehensive list of these organisations or individuals can be found on the Australian Institute of Occupational Hygienist (AIOH) website.

While the Workplace Exposure Standards have been in place for several years, a transition period has been set by Safe Work Australia to transition all of the WES to workplace exposure limits (WELs). This is to align with other international organisations, but to also reinforce to employers the need for exposures for employees to remain under the WELs. Up to the 1st of December 2026, the current WES list of contaminants is to be adhered to by employers, however after 1^st December 2026, the new WELs list will be enforced. Up to the date of transition, the current WES list for the contaminants is being reviewed to ensure the current list has reflected WES which may need to be lowered from any current trends or research.

The current list of WES can be found on Safe Work Australia’s website on the link below. Safe Work Australia WES list. Within the current list, it is also noteworthy to mention that noise is not covered. This is outlined within the WorkSafe compliance code for Noise.

Our HAZCON consultants have undertaken several occupational hygiene monitoring programmes across a wide range of industries and are able to provide assistance or information in relation to occupational hygiene monitoring. Please feel free to inquire on our website on the following link HAZCON .