New National Guidance Tightens Controls on Airborne Contaminants

Safe Work Australia has issued three new guidance documents to support workplaces in managing exposure to airborne contaminants and in getting ready for the transition to the national workplace exposure limits (WEL) list. These resources provide practical, targeted advice for persons conducting a business or undertaking (PCBUs), employers, occupational hygienists, technical specialists and workers in industries where airborne contaminants, including diesel engine emissions, may be present.

Australia is moving to the workplace exposure limits for airborne contaminants (WEL) list, with full implementation due on 1 December 2026. From that date, PCBUs must ensure that no person at the workplace is exposed to an airborne contaminant at a concentration above the exposure limit specified in the WEL list. Integrating these requirements into existing WHS management systems, policies and Safe Work Method Statements (SWMS) will be critical for compliance and risk control.

Under work health and safety (WHS) laws, PCBUs have a duty to protect workers and others from risks associated with airborne contaminants. The primary obligation is to eliminate risks so far as is reasonably practicable. Where elimination is not possible, risks must be minimised as far as is reasonably practicable through effective control measures, supported by appropriate WHS policies, procedures and monitoring regimes.

The first new resource is a practical guide for PCBUs on air monitoring and workplace exposure limits for airborne contaminants. It clarifies WHS duties in relation to the WEL and sets out how employers can protect workers from unsafe exposure. The guide explains when air monitoring may be required, how to engage a competent person to carry out monitoring, how to interpret and respond to monitoring results, and provides answers to common questions about air monitoring and workplace exposure limits. PCBUs are encouraged to embed these processes into their WHS management systems and to review relevant SWMS in light of the new information. For support with formalising procedures, businesses may consider structured WHS documentation such as those outlined at WHS management systems.

The second resource is a technical guide aimed at occupational hygienists and other technical professionals responsible for assessing exposure to airborne contaminants and determining compliance with workplace exposure limits. This guide offers detailed, practical advice on assessing exposure, planning and conducting air monitoring, interpreting monitoring data, and reporting findings to PCBUs along with appropriate recommendations. It is intended to promote consistent, high-quality air monitoring, data interpretation and decision-making across Australian workplaces.

The third guide focuses on exposure to diesel engine emissions. A new workplace exposure limit of 0.01 mg/m³ for diesel particulate matter will apply from 1 December 2026. Diesel particulate matter is used as an indicator of exposure to diesel engine emissions, which are associated with serious health outcomes, including lung disease and cancer. The guide emphasises the importance of understanding the health risks, identifying all potential sources of exposure and implementing suitable control measures to safeguard workers.

This diesel emissions guidance is relevant to anyone working in environments where diesel engine emissions may be present, including mining, quarrying, tunnelling, construction, agriculture, transport and logistics, oil and gas operations, and vehicle maintenance. The guide explains how to identify and manage exposure risks, plan and conduct air and health monitoring, and prepare for compliance with the new workplace exposure limit. PCBUs are encouraged to update their WHS management systems, SWMS and internal policies to reflect these requirements, ensuring that controls, monitoring and worker training are clearly documented and implemented in practice.

Together, these three new guidance documents are designed to help Australian workplaces strengthen their approach to managing airborne contaminants, align with upcoming workplace exposure limits and meet their WHS obligations by systematically identifying hazards, assessing risks, implementing controls and verifying that exposure remains below the prescribed limits.