Phosphine labels unchanged ahead of lower workplace exposure limit

Safe Work Australia’s current Workplace Exposure Standard for phosphine is due to be replaced by a reduced Workplace Exposure Limit (WEL) from 1 December 2026. Some states have advised they will delay implementation beyond December 2026, with details available through their WHS regulators.

Under the reduced WEL, persons conducting a business or undertaking—usually employers—must take appropriate measures to protect workers from phosphine exposure. Workplace exposure limits are health-based limits intended to protect workers from harmful airborne exposure.

There are currently 33 APVMA-approved products containing phosphine, including aluminium or magnesium phosphide. Their approved labels provide safe-use instructions and refer to 0.3 ppm under the heading ‘Ventilation period – on completion of the exposure period’.

That measurement applies to phosphine in an enclosure or work area and is used to clear grain after fumigation. It serves a different purpose from the WEL, which applies to concentrations in a worker’s breathing zone and is used to assess and manage worker exposure.

Following their assessment, APVMA and Safe Work Australia do not currently consider changes to phosphine product instructions necessary for users to meet their obligations under state or Commonwealth WHS laws.

APVMA is therefore leaving the labels unchanged at this stage. If new information indicates changes may be needed, it will consider regulatory action proportionate to the risk.

How Blue Safe can help: Our free WHS self-check can help you review your approach to workplace health and safety and identify areas for closer attention as exposure requirements change. Take the free WHS self-check