> ## Content Index > Fetch the complete content index at: https://www.whsbrief.com/llms.txt > Use this file to discover other available public pages before exploring further. # 0.3 ppm Is Not Your Exposure Limit: What the Phosphine Statement Says About WELs - URL: https://www.whsbrief.com/0-3-ppm-is-not-your-exposure-limit-what-the-phosphine-statement-says-about-wels/ - Published: 2026-10-27T22:30:00.000Z - Updated: 2026-10-27T22:30:00.000Z - Description: The 0.3 ppm on phosphine labels is a clearance figure rather than a health-based limit, which makes it a useful test of every number your site manages to before 1 December. - Author: WHS Brief - Tags: blog On 22 October Safe Work Australia and the Australian Pesticides and Veterinary Medicines Authority issued a joint statement on phosphine. No changes are proposed to the labels of the 33 approved phosphine products ahead of the reduced workplace exposure limit. Those labels refer to 0.3 ppm as the level for clearing grain after fumigation. The agencies were careful to say that clearance figure serves a different purpose from the WEL. The WEL is a health-based limit measured in a worker's breathing zone. The current exposure standard is replaced by the lower WEL from 1 December 2026, although SA and WA have deferred the phosphine limit. On the surface this is a quiet regulatory note. Underneath it is a question every business with an airborne hazard should be asking with about five weeks to go: which number are you actually managing to? ### Two Numbers That Look the Same A label figure tells you when a space or a product is clear enough to handle. A WEL tells you how much of a substance a worker can breathe over a shift without harm. They are measured in different places for different reasons. It is very easy for a site to adopt the number printed on the product and assume it covers both jobs. Ask yourself about the substances on your site: - Is the number in your procedure a clearance level, a label figure or a health-based exposure limit? - Is your monitoring done in the breathing zone of the worker or at a fixed point in the room? - Do you know which of your substances has a lower limit from 1 December? - Do you know whether your state has deferred any of them? ### What WA Is Telling Its Mines WorkSafe WA published mining-specific guidance this month on the same transition. It names dust, silica, toxic metals, blasting gases and processing chemicals like cyanide as key exposures. It sets out five steps: identify contaminants, assess against the new WEL, apply the hierarchy of controls, document the outcomes, then review. It also notes inspectors may ask for updated health management plans, sampling schedules and fit-testing records. That last point is the one I would underline. The inspector's first question will not be "are you compliant?" It will be "show me." A health management plan that still quotes the old exposure standard on 2 December is evidence that the transition never reached your documents. WA has deferred the phosphine limit to 1 December 2029\. So a grain business operating in WA and in NSW may be working to two different phosphine figures from December. That is manageable, but only if someone has written it down. ### Carcinogens Change the Question The WA guidance also restates something worth repeating. For carcinogens with no safe exposure level, exposure must be eliminated or minimised so far as is reasonably practicable. Meeting the WEL is not the finish line for those substances. If your silica monitoring comes back under the new limit, that is good news. It does not end the duty to keep pushing exposure down. - Which of your substances are carcinogens? - For each one, is there a plan to reduce exposure further or only a plan to stay under the limit? - When did you last ask whether elimination or substitution had become practicable? ### One Thing to Do This Week Take your last round of exposure monitoring results. Put the new WEL beside each result. Highlight anything within reach of the new limit or above it. That list is your work for November. It is far better to find it now than when an inspector asks. If you were asked tomorrow which number your fumigation or dust procedure is built around, would you know where it came from?