New research is aimed at preparing the forest and wood products industry to best respond to potential revised regulations around wood dust exposure levels.
Operations across the timber supply chain, including sanding, sawing, cross cutting and drilling, all have the potential to create wood dust. In response to research strongly associating wood dust in the workplace with health issues like cancer, occupational asthma and atopy (or a tendency to develop allergic diseases), Australian regulations exist to keep exposure to wood dust in the workplace at a safe level.
“In recent times, Safe Work Australia has made changes to similar regulations around crystalline silica dust and coal dust,” said Dr Roger Meder, Principal at Meder Consulting, which undertook the recent FWPA-commissioned research.
“It is inevitable therefore, that wood dust exposure levels will be reviewed in the near future, meaning changes to regulations may be on the way.”
One important element of the project was an extensive literature review, which focused on current regulations around the world, and how Australia compares. There is particular interest in the distinctions between regulations relating to hardwood and softwood dust.
“Traditionally, exposure to hardwood dust in the air has been considered more harmful than softwood dust,” explained Meder.
“Surprisingly, the literature review did not reflect this widely-held assumption. In fact, there is a growing body of evidence to suggest there is actually little difference between the harmful effects of hardwood and softwood dust.
“Attention should instead be paid to the particle size of the dust, regardless of whether is has originated from hardwood or softwood, as science suggests a small amount of fine dust is more harmful than a greater amount of dust containing larger particles.
“This is likely due to the potential for smaller, respirable dust particles to penetrate deeper into the lungs, and even make their ways into the bloodstream. Larger particles meanwhile, tend to get trapped in the nasal cavity, meaning they have less potential to cause long-term respiratory harm, although nasal cancers and work-related asthma may result.
“Unsurprisingly, sanding operations tend to produce both the greatest volume of dust, and also dust with the smallest sized particles. Exposure levels recorded for sander operators often exceed the regulated occupational exposure level (OEL) by several times.”
Currently in Australia the OEL for hardwood dust is 1mg per m-3 of air (time-weighted over an eight-hour shift), which represents one of the lowest regulated acceptable levels in the world. Meanwhile, the softwood regulation represents one of the highest acceptable levels in the world, at 5mg per m-3 of air.
Elsewhere, there seems to have been a reflection of the shift in thinking towards the impact of total respirable dust over wood species. Many jurisdictions around the world, including in the European Union, have much lower regulated acceptable levels for softwood dust, of 2 or 3 mg per m-3 of air. New Zealand, currently with a regulated level of 2 mg m-3 for softwood dust, is considering changes that will bring this into line with a recent revision of the hardwood limit, bringing it down to 0.5 mg m-3.
“With this in mind, we can probably expect softwood and hardwood OELs in Australia to increasingly merge in the future,” said Meder.
The second element of the research included a survey of workplaces from 13 global processors regarding the wood dust exposure mitigation steps currently in place. This work found the most common control methods to minimise worker exposure included Personal Protective Equipment (PPE), air quality testing, health screening of workers, improved or updated extraction systems, and shrouding of equipment.
“While current regulations don’t specify how often the air needs to be tested, this is something a revised set of regulations may look to address in the future,” said Meder.
In order to help prepare industry for these changes, the research collated information around the costs of mitigation practices, with most companies spending less than $100,000 on capital works. The majority of those surveyed reported installing, or upgrading, an existing extraction system to be of most benefit. Meanwhile the cost of ongoing air quality and health monitoring was found to be less than $10,000 per year.
“This knowledge could provide a valuable reference for industry to use once Safe Work Australia starts taking steps to revise regulations around wood dust, with additional information about the steps that can be taken to mitigate exposure and the associated costs clearly defined,” said Meder.
