Combustible dust is a potentially hazardous by-product of certain manufacturing processes involving certain raw materials. Also known as explosive dust, it can be almost invisible to the naked eye. However, it can create a highly dangerous dust hazard in the workplace if the appropriate safety measures are not in place.
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Under certain conditions, this type of dust can become explosive, potentially leading to serious injuries and even fatalities. As well as the risks to employees health and safety, combustible dust can also destroy machinery, or even entire business premises.
How is dust flammable?
Dust explosions can occur when there is a high concentration of combustible dust particles within an enclosed place.
When mixed with oxygen, fine dust particles can ignite if they come into contact with any ignition source. This can be anything from a spark or metal ember to a carelessly discarded cigarette end.
The dust can begin combusting rapidly within an enclosed space, resulting in a dangerous high-pressure airwave forming.
If the airwave explodes out of the enclosed space, it can stir up or dislodge combustible dust elsewhere in the premises.
As more dust mixes with oxygen in the air, the explosion can be even bigger. This can potentially cause further dust explosions as the fire spreads.
The risks to employees are overwhelming and there is a real likelihood that industrial equipment will be destroyed in these scenarios.
Which types of dust are the most flammable?
This is a common issue affecting a wide range of work environments and industries.
The most flammable materials include wood, several kinds of chemicals and light metals often found in industrial manufacturing plants. They also include some agricultural products such as spices, grains and tobacco.
Various industrial processes can typically create combustible dust including crushing, blasting, cutting, grinding, sawing, milling and polishing. In addition, 3D-printing when using powder can also lead to combustible dust forming.
As the dust is so minute, it can gather in plain sight, but it may not be immediately visible. It can also collect in places where it might not be easily detected.
How can companies reduce the risks?
Effective dust control strategies are essential to mitigate the risk of explosions. Companies must take action to maintain employee safety and protect the premises.
Appropriate safety procedures must be put in place: reliable dust extraction solutions will not only help to keep your workforce safe, but they will also ensure you comply with COSHH regulations (the Control of Substances Hazardous to Health).
Our AirBench downdraught benches are self-contained workbenches with built-in dust and fume extractor systems. They will draw dust down through the bench’s surface into the internal filters, returning clean air to the room. No installation is required: simply plug them in, switch them on and start work.
Wet filtration systems
Some types of combustible dust, such as titanium and magnesium, are too reactive to be safely captured using dry filtration systems.
Titanium is commonly used in aerospace applications and is extremely hazardous. During certain manufacturing processes, it can produce sparks. As the dust produced is flammable, titanium processing is considered extremely high risk.
Mixed dusts can also be potentially hazardous such as mixing steel and aluminium dusts, for example. This can generate a thermite reaction, meaning the dusts can self-ignite. For these applications, we recommend using wet filtration systems.
Wet filters combine water with a self-induced scrubbing action to remove dust from the airstreams. The dust is removed as a sludge from the filtration unit and can then be disposed of through your business’s regular dust disposal supplier.
We can provide extraction solutions to specific dust, fume and mist problems.
Dangerous dust incidents
A study entitled ‘Lessons Learned from Incidents’ revealed almost 1,000 dangerous incidents involving dusts and powders in the workplace were reported to the UK Health and Safety Executive over a 30-year period. Almost half involved dust explosions. This led to a total of 39 fatalities and 1,357 injuries.
A second report, compiled by risk management specialists HFL Risk Services, suggested many companies and employees simply didn’t realise just how hazardous dusts could be in confined workspaces.
The report concluded proper dust collection equipment and dangerous dust safety training for employees were the key to preventing potentially deadly accidents from occurring.