The revised workplace exposure limits, which SWA says are based on current scientific evidence and independent expert advice, were agreed by work health and safety ministers and published in April 2024. They are scheduled to take effect on December 1, 2026, following a public consultation process conducted between 2019 and 2021.
West Australian Grain Group chair Alastair Falconer said farmers were alarmed by an 80 per cent reduction in the accepted exposure limit for phosphine, a fumigant relied upon by the grain industry to keep insects out of stored and exported grain. “It's concerning, and I'm not sure if there's equipment that can measure such [new] low levels,” he said, adding that the new rule “almost renders phosphine unusable”.
Mr Falconer noted that many importing countries reject entire shipments if insects are found due to biosecurity laws, making phosphine critical to Australia's $33 billion grain export industry. He also said exposure limits for grain dust — including oats, wheat and barley — had been more than halved, and the industry was scrambling to understand how to measure exposure and comply.
“When we're blowing down harvesters, we're cleaning out our own silos, what exposure is that giving us, how do you measure exposure when you're blowing down a harvester, and what's the correct PPE to use to make sure you don't go over this new limit,” Mr Falconer said. He called for a three-year delay in implementation to allow industry to research whether the levels are appropriate and how to manage them.
In a statement, Safe Work Australia said it recognised questions about how limits for phosphine and other airborne contaminants are applied in practice and is working with industry stakeholders and other government agencies — including the Australian Pesticides and Veterinary Medicines Authority and the Department of Agriculture, Fisheries and Forestry — to support a consistent understanding of the requirements. SWA said the revised limits reflect current scientific evidence and independent expert advice. Farming groups are calling on the government to intervene.