Dust is a constant and enormous health risk in all lines of industrial work, including the school workshop. You may not be able to see it, but microscopic particles of silica, wood, asbestos and other nasties can travel deep into your lungs, leading to potential long-term diseases.
Therefore, knowing how to handle hazardous dust in the workshop is extremely important.
But what exactly is hazardous dust? What health risks does it pose, and how can we protect against it?
To prevent dust from causing any long-term health problems, you need to extract it at the source.
Dust extraction helps to remove harmful dust from the atmosphere. When implemented correctly the harmful dust is captured so that it can be disposed of safely at a later date.
The best tools and extraction equipment will ensure dust is kept from transferring into the air around you.
For instance, Festool power tools are designed to maximise dust extraction. Their equipment is designed with health and safety as a major concern, and are built as systems that easily click together to funnel extracted dust away.
The Main Dust Classes
There are three main classes of industrial dust you should be aware of.
These classes are ranked based on the particle size, and the risk they can pose to your health. The smaller the particles, the more chance you have of breathing them in, which is where there is greater risk of dangerous particles settling in your lungs and causing damage.
The main dust classes:
Dust Class L (Low risk, largest particles)
L-Class dust is considered some of the least harmful and can be commonly found in the home. Everyday house and soil dust, for example, would fall under ‘L’. Therefore, there is a smaller long-term risk in you breathing this in, though you must still take precautions.
Class L extractors operate at 99% efficiency and therefore work to an occupational exposure limit of 1mg per metre cubed.
Dust Class M (Medium risk, small particles)
M-Class dust is considered medium risk. While this type may not pose the same long-term health risks of class H, it is still highly recommended that you protect against it. Dust class M is common in most industrial workspaces.
Wood and quartz-based materials are likely to be the most common cause of the spread of M-class dust. You may create this dust class while working with any of the following:
- Cement (standard or tile)
- Repair compound
- Paint (oil and latex)
Festool M class extractors come fitted with a flow sensor and alarm that advises the user when a dust bag or system is full, or if attention is required. As this dust class is considered more hazardous, it is vital that hardware is kept running at an optimal level at all times.
Class M extractors and filters operate at 99.9% efficiency. That means there is an occupational exposure limit of 0.1mg per meter cubed.
Dust Class H (High risk, microscopic particles)
H-Class dust is regarded as the most dangerous. This type of dust can travel the furthest into your lungs, and therefore may be considered carcinogenic, or at greatest risk of causing cell necrosis.
Materials likely to create H-class dust and respirable silica may include:
- Mould spores
- Mineral and artificial fibre
Class H filtration and extraction systems operate to 99.995% efficiency and occupational exposure of 0.1mg per metre squared.
Festool dust extractors are compatible with various types of filters and bags. Failure to use a bag during extraction may result in dust re-entering the atmosphere. What's more, you would also need to clean your hardware regularly.
Filter bags are ideal for use with all dust classes. Long life bags help with class L in particular, though self-cleaning bags are ideal for all-round support.
If you are working with harmful dust on a regular basis, consider auditing your current equipment and tools. Are they doing enough to keep the air clear of dust, whether Class L, M or H?
Vacuum filters are one of the most important feature of your extractor. They come in many shapes and sizes as well as an array of functions. Some filters protect the motor from dust and debris, working to extend the life of the vacuum. Others filter expelling air before it leaves the vacuum so as not to redeposit debris back into the area you are cleaning. Some filters are HEPA, which is ideal for homes and workplaces battling asthma, allergy or virus concerns.
I personally find this time of year the perfect time to change filters and bags, because as the cold winds of winter start blowing, the workshop doors start closing. Without that gust of fresh air, up to date and perfectly efficient filters are essential.
Disclaimer: This information is not endorsed by any Work Health and Safety governing body and shouldn't be interpreted as any form of legal or health advice. All regulatory and compliance enquiries must go to the relevant Worksafe organisation responsible for each region of Australia.