WHS Regulation 2025, Part 7.1

Regulation

Uncertainty about WEL compliance

Trigger

Competent person (occupational hygienist)

Performed By

30 years minimum

Record Retention

1 December 2026

WEL Transition

Paid by the PCBU

Cost

You need air monitoring when you cannot be certain that airborne concentrations of hazardous chemicals in your workplace are below the applicable workplace exposure limit. This uncertainty arises whenever workers are exposed to airborne dusts, fumes, vapours, gases, or mists generated by work processes. Common trigger situations include cutting, grinding, or drilling materials that generate respirable dust such as concrete, stone, timber, and metals. Welding, soldering, and brazing operations that generate metal fumes. Spray painting, coating, and adhesive application that generates solvent vapours and isocyanate aerosols. Chemical mixing, blending, and handling operations that generate vapours or dust. Any process that generates airborne contaminants in an enclosed or poorly ventilated space. You also need air monitoring when a health monitoring result indicates that a worker may have been exposed above the WEL, or when a health and safety representative reasonably requests monitoring to assess exposure levels.

You do not need air monitoring when you can be certain on reasonable grounds that airborne concentrations are below the relevant WEL. This certainty can be based on previous monitoring results that demonstrate consistently low exposures under the same or similar conditions, published exposure data for equivalent processes and controls, engineering controls that demonstrably capture contaminants at the source before they enter the breathing zone, or the use of substances in quantities and conditions that cannot generate airborne concentrations approaching the WEL. The basis for your certainty must be documented and must be reviewed whenever work processes, ventilation, substance quantities, or other relevant conditions change. You do not need air monitoring for substances that do not have a WEL, although you must still manage the risk of exposure using the hierarchy of controls. Note that with the WEL reductions commencing December 2026, previous monitoring results that showed compliance under the old WES may no longer demonstrate compliance under the new WEL.

Air monitoring under the WHS Regulation 2025 must be carried out by a competent person. In practice, this means an occupational hygienist or a person with equivalent qualifications and experience in workplace exposure assessment. The competent person must select the appropriate monitoring methodology for each substance, which typically involves personal air sampling using calibrated pumps and substance-specific collection media worn in the worker's breathing zone during representative work activities. The sampling and analytical methods must comply with the relevant Australian Standard or internationally recognised method. The competent person must prepare a report that includes the monitoring methodology, the results expressed as time-weighted average concentrations, a comparison against the applicable WEL, and recommendations for control improvements where results approach or exceed the WEL. Air monitoring records must be kept for at least 30 years. The PCBU must ensure that monitoring results are communicated to affected workers and their health and safety representatives.

The transition to new workplace exposure limits on 1 December 2026 significantly expands the population of businesses that need air monitoring. Many businesses that previously operated below the old workplace exposure standards will find that their exposures approach or exceed the new WELs. Silica, welding fume, wood dust, diesel particulate, formaldehyde, isocyanates, and numerous solvents have reduced WELs that will require monitoring to verify compliance. During the transition period, best practice is to conduct baseline monitoring under current conditions and compare results against both the current WES and the incoming WEL. This dual assessment identifies which tasks and processes will be non-compliant under the new limits and allows time for engineering control upgrades. Businesses should engage occupational hygienists now to schedule baseline monitoring, as demand for monitoring services is expected to increase significantly as the December 2026 deadline approaches. Early movers will secure service availability while late movers may face delays and premium pricing.