Wood Dust and Flash Fire Risks: Safety Insights and Legal Warnings from McCarron Coates

Think flash fires is the message for some manufacturers from commercial insurance broker, McCarron Coates, as it highlights the fire risk wood dust can pose within manufacturing.

Flash fires are not as frequently discussed as flash floods but can be equally devastating.  They occur when highly combustible wood dust, comprising fine wood particles, are suspended in the air in sufficient concentration and become an easily ignited cloud, potentially set alight by a nearby ignition source. In the worst cases, an explosion can occur.

The ignition source could be a naked flame, an unintentional spark, the build-up of surface heat, static or a number of other causes.  With little or no warning, the resulting fire can shoot through a building, potentially even causing a second explosion, as it stirs up more wood dust whilst travelling through.

Within certain environments, the chances of suffering a flash fire are way higher than those of a flash flood.  It is not only wood dust clouds that are latent dangers issue but also stacks of contained wood dust, within which pressure can build.  Even a small layer of wood dust left laying on a surface can be a fire hazard.

The finer the dust, the higher the explosion risk.  Particles under 200 microns are usually explosive, as is a mixture in which as little as 10% of the dust measures under 80 microns.  Verifying whether dust is a danger can be achieved through a dust explosion test.

Controlling wood dust is absolutely essential, not just because a fire could lead to loss of life but because the law expects employers to be on top of this.

The UK legal framework is headed by the Health and Safety at Work Act of 1974, which places a duty of care on the employer.  They must take all practicable measures to ensure the health and safety of employees.

Then, there are the COSHH (Control of Substances Hazardous to Health) Regulations of 2002.  Employers must control substances, including wood dust, known to have negative health impacts.  Wood dust is a respiratory hazard known for causing asthma and lung diseases like COPD.  In the USA, it is classed as a Group 1 carcinogen.  It can contain bacteria and fungal and moss spores, all of which can trigger respiratory health problems.

It also falls under Dangerous Substances and Explosive Atmospheres Regulations (DSEAR), 2002.  Under this legislation, any manufacturer generating wood dust in their workplace should have procedures in place to assess the risk of explosion and prevent and mitigate it.

Controlling ignition sources is another consideration, with measures to do this including maintaining equipment - as expected by the PUWER (Provision and Use of Work Equipment Regulations) of 1998.

Employers must ensure they also remain within the required Workplace Exposure Limits governing wood dust generated by hardwoods, softwoods or a mixture of both. They continually need to stay on top of wood dust and comply with all regulations. 

To do this, McCarron Coates suggests manufacturers refer to the Hierarchy of Controls, of which the very minimum control is protecting workers through use of PPE equipment.  

Luigi Maggio, Director at McCarron Coates, says: “Whilst the use of RPE is nowhere near as efficient as eliminating wood dust at source, it will offer some protection.  The proviso to this is that protection is dependent on having the right particulate filters within disposable masks, ensuring correct face-fitting of disposable and half masks, and using only special RPE equipment for those with facial hair, for whom certain RPE is not suitable.”

Above this minimum level of protection in the Hierarchy of Controls lies administrative controls, which means changing the way people act around wood dust.  For instance, wood dust should not be vacuumed using a standard vacuum, as that could prompt an explosion. Instead, it needs to be picked up by ATEX industrial safety vacuums, with the selection of the right equipment for the individual workplace being a key part of the risk management.  

Wet cleaning of layered dust is a way to prevent dust rising. Dry sweeping will cause more dust to circulate and should not occur.  Special attention should be paid to high shelving or other places where wood dust could lurk undetected.

Removing wood dust at source is essential. It is advisable to use LEV systems to capture and extract wood dust-ladened air. Such equipment can operate around processes such as cutting, sanding and shaping wood – all of which generate significant amounts of wood dust. Catching wood dust before it has a chance to circulate and then taking it away to be treated and filtered in the optimal way is the preferred option.

“The LEV equipment again needs to be fit for the facility in which it will operate, with correct product selection being part of the risk management process.  Under COSHH regulations, it also needs to be inspected and tested every 14 months,” says Luigi Maggio.

Higher up the Hierarchy of Controls is ‘replacement of the hazard’. Whilst it may not be possible to replace wood completely, McCarron Coates highlights how some woods are more hazardous to health than others.  If a swap is possible, it could be advantageous.

At the very top comes ‘elimination’.  If wood-related cutting, sanding and shaping processes are not essential to the product being manufactured, it may be advisable to remove them.

“Training staff in all aspects of wood dust control is vital for employee health and also for the mitigation of the flash fire risk,” says Luigi Maggio. “Employees need to understand the correct cleaning methods to use, how to wear RPE correctly and the emergency evacuation procedures, should a fire break out.  Fire drills should be held regularly and staff should be encouraged to report hazards or possible sources of ignition.  Hot work needs to be strictly controlled and good machine maintenance needs to be practised, so as to prevent equipment from overheating, sparking, or experiencing static build-up.

A flash fire can occur out of seemingly nowhere and take hold rapidly. Manufacturers must ensure they do all they can to prevent this and abide by the various regulations relevant to wood dust. Over and above that, they should keep a keen eye on their sums insured and work with an expert broker, like McCarron Coates, who understands their sector, to make sure that, should the worst occur and a fire break out, they are not exposed to financial loss by being underinsured.”

For more help with managing risks like wood dust, call McCarron Coates on 0113 298 3489 or visit www.mccarroncoates.com