It’s been a while between hygiene checks lately, so I thought I’d get back to basics with the dust mask, or to be technical, the “air purifying respiratory protective device“. This has to be the most common thing people associate occupational hygienists with. The “dust mask” lady is coming, I can hear it already.
Respirators, or “dust masks” can commonly be seen as an easy solution to a dust problem, but in fact, when you do all the things you are supposed to do, you quickly realise that going higher up the control hierarchy and suppressing the dust or using ventilation is going to be easier in the long run.
Here are some things to keep in mind before you run to use (or give your workers) respirators:
1. The WHS Regulations require that risks to health and safety are eliminated, and where not reasonably practicable to do so, that they are minimised so far as reasonably practicable. You need to control the risk in accordance with the hierarchy of controls by first substituting the hazard, secondly isolating the hazard, or thirdly by implementing engineering controls and document all of it. If the risk then remains, then you can use administrative controls, with the residual risk controlled by the use of PPE. You can’t jump straight to the use of respirators (or PPE) first.
2. The use of respirators as the sole control to exposure to hazardous substances relies heavily on worker compliance, worker acceptability and the uncertainties and unpredictability of worker attitudes and behaviour. A significant amount of compliance effort is involved where respirators are used. So expect to spend some time performing and documenting inspections for compliance, having discussions about why its important, and when and where to use them.
3. A comprehensive Respiratory Protective Programme must be developed before you provide respirators to the workforce. Such a programme is explained in AS/NZS 1715:2009 and includes the following items at a minimum:
- The basis for selection of the particular PPE;
- Medical screening for each employee assigned to wear the PPE;
- An employee training programme where the worker can become familiar with the PPE and includes its proper use, the nature of the hazard, and the need for protection;
- Training in the limitations of the PPE;
- Proper fitting of the PPE (fit testing);
- Regular cleaning and disinfection of the equipment (or when to dispose of it and get a new one)
- Proper storage of the equipment;
- Provision for periodic inspection and maintenance of the equipment and replacement where required; and
- Periodic evaluation to assure its continuing effectiveness
4. If you are uncertain if the Workplace Exposure Standard for the hazardous substance will be exceeded, then you need to perform air monitoring to determine the airborne concentration of the hazardous substance (eg: dust) in the air. This means you need to do personal exposure monitoring, which is different from static monitoring (ie: putting a sample pump in the work area or measuring it using a DustTrack). You also need more than one sample…but you knew this already!
These are just a few items to consider before you hand a worker a dust mask. Keep in mind that different chemicals (and dusts) have different properties and may require different types of respiratory protection (not all dust masks are created equally!).
If you have questions or need help, then you should contact your friendly occupational hygienist. The AIOH has a Consultant directory here.