GPA QUESTIONS SCIENTIFIC BASIS OF NEW GRAIN DUST LIMITS AHEAD OF HARVEST

Grain Producers Australia (GPA) has identified massive concerns with the use of a single Dutch study in the evaluation process the Federal Government have used to justify a huge drop in safe work exposure limits for grain dust.

The study used data that is over 40 years old on the wrong grain types, to set new regulations that could make grain production almost impossible.

GPA have reviewed the outdated evidence used by SafeWork Australia (SWA) to evaluate the current grain dust standard and recommend the new heavily reduced limit which is set to come into effect in 35 days.

SWA commenced a review of approximately 700 airborne contaminants, including grain dust, in 2018 which they claimed would “assess evidence related to the human-health impacts of airborne contaminants” and “recommended changes to the exposure standards to ensure they are based on the highest quality, contemporary evidence and supported by a rigorous scientific approach.”

Considering grain growers are anticipating this new exposure level will be extremely hard for them to comply with the evidence used to set the new grain dust exposure level appears to also create an unjustifiable and unreasonable regulatory burden for them.

Outdated evidence

In reviewing the standard for grain dust, SWA took 40-year-old data to set new limits that could bring the grain industry to its knees.

The formal SWA Workplace Exposure Standard (WES) Evaluation Report for Grain Dust (oats, wheat, barley) referenced only two research papers and recommended a finding from the single Dutch paper from 2011, with its finding deduced from two North American studies conducted in 1982 and 1983.

While this evidence seems far from “high quality, contemporary evidence”, it also fails to compare apples with apples when it comes to Australia safe work standards.

Wrong grain types

The Australian workplace threshold for grain dust is explicitly specified by SWA as “Grain dust (oats, wheat, barley)”.

While the Dutch study clearly states it was undertaken with a grain dust definition of “fine particulate matter originating from several grains, such as wheat, oats, barley, rye, sorghum, and including maize, rice, pulses – such as soybeans and peas – and various oil seeds”.

Also concerning is that this new limit seems inconsistent with how SWA defines exposure limits.

Incorrect threshold

SWA guidance states that the new exposure limits to be enforced - “are the maximum level of an airborne contaminant that most (but not all) people can be exposed to without harm to their health”. 

Despite this, the evaluation recommended a new threshold where there are no adverse effects observed, despite the summary of the Dutch study stating that "in most studies, clear effects on the respiratory system are reported at grain dust levels exceeding 4-5 mg/m³" - which happens to be the current Australian standard.

Adopted by government

The new workplace limits are a result of the SWA airborne contaminant review and were accepted by all WHS ministers, who also agreed to a “harmonised transition to adopt” them on 1 December 2026.

This means the new limits that are set by SWA are to be adopted and enforced by all state and territory, accept where jurisdictions are starting to reassess and break ranks.   

Quotes attributable to Matthew Madden, GPA Chair

“I'm really concerned that Australian grain growers are supposed to comply with grain dust regulatory standards that are based on evidence that is over 40 years old, from Dutch research that is not consistent with the types of grain dust specified by the national regulator.

“GPA have become aware that this new grain dust threshold is likely to be extremely difficult for grain growers to comply with, but to now see the science being used to justify the change raises huge questions.

“It is quite confronting to see the impact this national evaluation process could have and may still have on our growers in an industry that is worth billions of dollars to the Australian economy.

“GPA are extremely grateful to the Victorian and South Australian Governments for delaying the implementation of this threshold in their states, but we don’t understand how this was ever recommended by SafeWork Australia.

“GPA have been working extremely hard with our members to survey them, develop online resources, and help them adjust to this change in good faith, and now we’re not sure who we can trust.

“GPA have taken the approach of working with governments and regulators to help them understand the needs of growers and negotiate outcomes that balance workplace safety and practicalities, but how can we say we represent our members and stay silent about this information?

“GPA will continue to work with governments on behalf of grain growers, but SafeWork Australia, all other regulators and governments need to hold up their end of the relationship too."