Ever heard this before? This is normally followed by the blank stare with mouth wide open as some poor soul stands there while I try to explain why ‘no it’s not!’
There are many common misconceptions on how to determine if the workplace air is ‘safe‘, but today I’m going to focus on just one….why one sample isn’t enough..or as we call it…why you need to perform personal exposure monitoring to assess occupational exposure to airborne contaminants!
Under the Work Health and Safety Regulations (I’ll assume we live in a perfect world where we are harmonized for simplicity), you need to do air monitoring to determine the concentration of substances in air where an exposure standard applies (there are over 700 exposure standards in Australia)…if a) you can’t prove that the concentration exceeds the exposure standard, or b) it’s necessary to determine if there is a risk to health (I’m paraphrasing).
In an all too common scenario, some will assume that ‘monitoring’ simply involves setting up a gas detector, or some ‘dust pumps’ in the work area…run them…and then compare the results to the respective exposure standard to conclude if you are safe or not and then bam you’re done. Unfortunately this isn’t the case. What can then follow is the Occupational Hygienist using all their powers of persuasion to convince someone that this isn’t enough to be in compliance with the Regulations.
In their defence…it’s also not that simple to figure out that you actually need to do this. So, I thought today I’d list out the standard blurb I use to show people that this is required.
2. Still on the WHS Regulations…the definition of ‘exposure standard’ refers you to the ‘Workplace Exposure Standard for Airborne Contaminants’
3. Look up that document and you find that a few interesting things:
a. Firstly, exposure standards, “Do not represent a fine dividing line between a healthy and unhealthy work environment. Natural biological variation and the range of individual susceptibilities mean that a small number of people might experience adverse health effects below the exposure standard”. Therefore they don’t protect ‘all’ workers. It is a brave (read: foolish) person who tells you that the workplace is ‘safe’ if there is known concentration of a hazardous chemical around and they have 1 sample to prove it.
b. It also reminds you that exposure to substances in the workplace “must be kept as low as reasonably practicable” and refers you back to the WHS Act.
c. …and it also has this statement, “Where monitoring of airborne contaminants is used to estimate a person’s exposure, the monitoring must be undertaken in the breathing zone of the person”. So therefore ‘static’ or ‘para-occupational’ samples where they are taken in the workplace, rather than from a worker’s breathing zone, aren’t going to be enough to determine if there is a risk to health…or to be in compliance with the WHS Regulations.
That document then refers to the Guidance Note on the interpretation of workplace exposure standards for airborne contaminants.
4. In that document, it’s quick to point out that, “Exposure measurements should be made from unbiased and representative samples of actual worker exposure. Such a sampling strategy usually encompasses selection of workers for personal monitoring as well as the timing of sampling. The monitoring strategy should also address issues such as the nature and duration of a process, sampling and analysis errors, statistical analysis of exposure data and the determination of the need for regular exposure measurement. Detailed routine monitoring strategies for airborne contaminants are a complex subject and a complete discussion of the theory and characteristics is beyond the scope of this Guide”.
Yes…health is complex – that is why it can take so long to actually become an Occupational Hygienist! Around Page 7 that Guidance document refers you to ‘seek expert assistance’, and this is where your friendly Occupational Hygienist comes in.
The above 4 points would have to be one of the most common document trails I rattle off when trying to explain why putting a dust pump on a stake in the middle of the work area isn’t going to cut it. Yet the look of disbelief is still a common occurrence.
What about you reading this now…is this new to you? Do you have any suggestions on how to better communicate the responsibilities of Companies on this issue?