The Australian Pesticides and Veterinary Medicines Authority (APVMA) and Safe Work Australia (SWA) have collaborated to assess whether changes to APVMA approved labels are required to facilitate the transition to a reduced phosphine workplace exposure limit (WEL) under work health and safety (WHS) laws.
Safe Work Australia’s current Workplace Exposure Standard (WES) for phosphine will be replaced by a reduced Workplace Exposure Limit (WEL) from 1 December 2026. Some states have advised that they will delay implementation of the WEL for phosphine beyond December 2026. Details can be found via state WHS regulator websites.
From 1 December 2026, persons conducting a business or undertaking (usually employers) must comply with this reduced WEL by taking appropriate measures to protect workers from exposure to phosphine. Workplace exposure limits are health-based limits used to protect workers from harmful airborne exposure. More information is available on Safe Work Australia's airborne contaminants hub.
Currently, 33 APVMA approved products contain phosphine (including aluminium or magnesium phosphide). The approved product labels contain instructions for the safe use of phosphine and include reference to 0.3 ppm under the heading ‘Ventilation period – on completion of the exposure period’. Measuring phosphine in the enclosure or work area to this value is used to clear grain following fumigation and serves a different purpose to the WEL. The WEL is a health-based limit for concentrations in a worker's breathing zone and is used to assess and manage worker exposure.
The APVMA and SWA do not currently consider that changes to the instructions for use of phosphine products are necessary to enable users of those products to comply with their obligations under state or Commonwealth WHS laws.
The APVMA is therefore not proposing changes to phosphine product labels at this time. However, if new information becomes available that may indicate that label changes are required, the APVMA will consider regulatory actions as appropriate proportionate to the risk.