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In March 2020, Safe Work Australia paused the release and public consultation for the workplace exposure standards (WES) review until further notice. Public feedback resumed on 1 February 2021 with Release 15: paraffin wax to zirconium compounds. This release will be open on our consultation platform, Engage until 30 July 2021.

The public feedback process for releases 2 to 14 closes on 1 February 2021. For the latest information please continue to visit Engage.

Stay informed about the WES review by subscribing to the chemical exposure standards mailing list

Overview

Safe Work Australia is reviewing the workplace exposure standards (WES) for airborne contaminants to ensure they are based on the highest quality, contemporary evidence and supported by a rigorous scientific approach. 

The current limits are published in the Workplace exposure standards for airborne contaminants list. However, toxicological knowledge and recommendations of airborne hazardous chemicals have advanced significantly since the WES were first adopted in 1995.

The aim of this review is to develop a list of health-based recommendations for WES in Australia. This includes recommendation on the WES values, notations and the list of chemicals. Recommendations are informed by an evaluation of available information from trusted domestic and international sources. Only publicly available information is being used.

The evaluations of individual chemicals commenced in 2018 and continued into 2020. These evaluations include an independent peer review process.

Individual evaluation reports for each chemical are being published in ‘releases’ for public feedback.  For more information on the public feedback process, please refer to our Engage platform.  

All recommendations for WES resulting from this review will be considered by Safe Work Australia Members, along with the feedback provided by stakeholders.  Safe Work Australia Members will then make recommendations to Work Health and Safety Ministers as the relevant decision makers. 

Changes to the WES only become mandatory once adopted in the WHS laws in the Commonwealth, states and territories. There will be a standard three year transitional period for duty holders to comply with any amendments.  

Introduction

The limits to which workers can be exposed to hazardous airborne chemicals are published in the Workplace exposure standards for airborne contaminants (WES list).

The values published in this list are the airborne concentrations of a chemical that are not expected to cause adverse effects on the health of an exposed worker.

WES values are generally based on the adverse effect that occurs at the lowest airborne concentration of the chemical, or the ‘critical effect’.

There are three WES parameters under the model WHS laws:

  • if the critical effect is a chronic or sub-chronic effect:
    • eight-hour time-weighted average (TWA), and
  • if the critical effect is a short term or acute effect:
    • short term exposure limit (STEL), or
    • peak limitation.

Review methodology

The methodology to update the workplace exposure standards addresses selecting trusted sources of information, the composition of the WES list and how to come to a recommendation for a specific chemical.

Criteria for the selection of trusted sources

A workplace exposure standard recommendation is determined by evaluating:

  • primary sources of data that form the basis of decision-making for recommending a workplace exposure standard for a hazardous chemical, and
  • secondary sources of data used where there are significant data gaps or in a weight of evidence approach where there is uncertainty arising from primary sources.

Trusted sources

Primary sources

The following bodies met the criteria for trusted primary sources of data:

Secondary sources

The following bodies met the criteria for trusted secondary sources of data:

Sources for notation recommendations

Advisory notations accompanying the workplace exposure standards include:

  • carcinogens (Carc. 1A, Carc. 1B, Carc. 2)
  • sensitisers (Sen), and
  • chemicals where significant absorption and toxicity may occur via the dermal route (Sk).

Under the model work health and safety (WHS) laws, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is used for classifying hazardous chemicals.

The following bodies are used to inform carcinogenicity and sensitiser notations for the workplace exposure standards in this review:

Information available in the primary and secondary sources can also inform whether a classification or notation may be required.

Criteria for the selection of hazardous chemicals to be added to or removed from the WES list

Criteria for identifying chemicals to be added or removed from the WES list have been developed to ensure it is reflective of contemporary Australian workplaces.

The chemicals identified were made available for public consultation through the regulation impact analysis process and considered by Safe Work Australia Members.

The lists of chemicals that meet the agreed criteria are included in the Selection of hazardous chemicals to be considered for addition to or removal from the workplace exposure standards list

The chemicals being added to the WES list are being evaluated as part of the WES review. 

Recommending health-based workplace exposure standards and notations

Recommendations for workplace exposure standards for each chemical will be made by following a consistent process of decision-making, and evaluating the information from the primary data sources (with supporting information from secondary sources where appropriate). Recommendations will also be made for values and notations for carcinogenicity, sensitisation of the skin or respiratory tract, and a skin notation where there is a risk of the chemical being absorbed through the skin.

This process may result in a recommendation to:

  • keep the existing WES value or notation
  • amend the WES value or notation, or
  • to withdraw the existing values or notations.

In some cases, there may not be enough data available for a recommendation or there may be uncertainty about the data. In these cases, an interim WES value may be recommended, accompanied with either:

  • a recommendation for a further assessment of the data for the chemical, or
  • a recommendation for a priority evaluation of the data for the chemical in the next scheduled review of the workplace exposure standards.

Each evaluation is then peer reviewed by an independent expert.

Following completion of the evaluations and peer review process, individual chemical evaluation reports are made available for public feedback via our consulting platform, Engage

Criteria for a skin notation

 Some of the characteristics of the chemicals on the WES list pose a risk of being absorbed through the skin. The WES list assigned a ‘Sk’ notation for these chemicals to alert PCBUs to this risk.

Criteria have been developed to ensure the notation is consistently applied based on the evidence available from the trusted sources.

Non-threshold based genotoxic carcinogens

Some of the characteristics of chemicals on the WES list mean that there is no level of exposure without a risk to health.

An approach has been developed to identify these chemicals and calculate a level at which the risk is considered ‘minimal’.

Immediately Dangerous to Life or Health

An additional advisory notation, an Immediately Dangerous to Life or Health (IDLH) parameter, will be provided for some chemicals on the WES list.

This parameter was developed by the US National Institute for Occupational Safety and Health (NIOSH) to represent an airborne concentration of a chemical capable of:

  • causing death, or immediate or delayed permanent adverse health effects to a worker, or
  • impeding their escape from such an environment.

An IDLH is not considered an exposure standard; it is a concentration that may cause harm, rather than a concentration at which no adverse effects are expected.

However, an IDLH provides PCBUs and workers additional safety information for specific situations, such as working in confined spaces, industrial accidents (including chemical spills or explosions) or other uncontrolled-releases. These parameters may help guide accident prevention and emergency response planning in the workplace.

Regulation impact statement – workplace exposure standards framework

Consultation regulation impact statement

In 2018, we published a consultation regulation impact statement (consultation RIS) to determine the impact of, and best way to implement, an update to Australia’s workplace exposure standard framework.

The consultation RIS outlined and tested the current state of knowledge regarding the costs and benefits of the status quo, and presented potential options to address the problems identified with the current workplace exposure standard framework.

It explored whether the workplace exposure standards should remain mandatory under the model Work Health and Safety laws or if advisory status is more appropriate. It also explored changing the name of workplace exposure standards to workplace exposure limits. 

The consultation RIS was supported by a six week public consultation period. We received 31 submissions with valuable feedback from a range of stakeholders including, WHS regulators, government, industry and industry groups, unions, professionals and other interested or affected people.

A consultation summary and submissions received are available to read on our consultation platform, Engage.

Decision regulation impact statement

The submissions from the consultation RIS informed the Decision regulation impact statement: Workplace exposure standards framework under the model Work Health and Safety laws (decision RIS).

The decision RIS was prepared to provide a recommendation to WHS Ministers on the preferred option for implementing an update to Australia’s workplace exposure standards and the status of the workplace exposure standards under the model WHS laws.

A majority of WHS ministers agreed to the preferred option in the decision RIS. This means:

  • there is no change to the requirement to ensure exposure standards for substances and mixtures are not exceeded (Regulation 49)
  • the Workplace exposure standards for airborne contaminants will be updated using the agreed methodology, and
  • the name of workplace exposure standards will be changed to workplace exposure limits.

There will be a standard three year transitional period for duty holders to comply with amendments to the workplace exposure standards.

Educational and guidance materials will be developed to support implementation and compliance.

Safe Work Australia will work closely with the Commonwealth, state and territory WHS regulators to implement the preferred option.

Stay updated

Stay informed about the workplace exposure standards review by subscribing to the chemical exposure standards mailing list

If you have any further questions about workplace exposure standards, email WES@swa.gov.au.

Public feedback process

For more information on the public feedback process for the workplace exposure standards review, please see our consultation platform, Engage.  

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