Fire Risk Assessment - Manufacturing and Industrial (Combustible Dust)

Manufacturing and Industrial Processes Involving Combustible Dust

Dust Containing Systems - Fire Risk Assessment

While many of the areas which house dust containing systems will be subject to the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) they will also require Fire Risk Assessments to be carried out in accordance with the Regulatory Reform (Fire Safety) Order 2005 (RRFSO). There are a huge range of materials that fall into this category – See list of Combustible Dusts.

The effects of a Combustible Dust fire can be catastrophic due to the fact that the initial combustion can trigger explosions that in turn throw more dust into the air and cause secondary explosions. The after effects of a combustible dust fire can appear not unlike a war zone – total devastation!

Oakleaf have considerable experience in conducting fire risk assessments in high dust environments. These can be any facilities which transport, handle, process or store Agricultural Products, Agricultural Dusts, Carbonaceous Dusts, Chemical Dusts, Metal Dusts or Plastic Dusts. The product lists are extensive but irrespective of the actual material they all have the potential for a Combustible Dust deflagration or explosion.

Definition:

‘A Combustible Dust is a particulate solid that presents a fire or deflagration hazard when suspended in air or some oxidising medium over a range of concentration, regardless of the particle size.’

If as little of 5% of the floor area is covered by dust to a depth of only 0.8mm thickness then this can produce a combustible dust cloud. If this amount of dust is agitated so that it is thrown into the air (either by an explosion elsewhere or a violent impact) then this would be enough to produce a cloud with a Minimum Explosive Concentration (MEC) of up to 6 feet deep! Dust of this quantity can often accumulate in high level recesses on building structures or above suspended ceilings, so even though everywhere at normal working level may appear to clean and safe there can still be enough accumulated dust to trigger a catastrophic event.

As a guide if you can see a foot print in the surface of the dust or can write your name in it then there is already too much dust accumulated and there is the potential for a combustible dust cloud.

dust-depthdust-footprint

Left: Footprints visible in dust - depth already too great. Right: Dust depth identified at 38mm - a catastrophe waiting to happen!

Combustible Dust hazards exist in a variety of industries including: Agriculture, Chemicals, Food (sugar, spice, starch, flour, cereals, feed), Grain, Fertiliser, Tobacco, Plastics, Wood, Paper, Pulp, Furniture, Textiles, Pesticides, Pharmaceuticals, Tyre and Rubber manufacture, Dyes, Coal, certain metal Processing, Recycling, Fossil Fuel and Bio-Mass power generation.

Our fire risk assessment includes detailed analysis of dust accumulation and structure design, housekeeping methods and frequency, cleaning equipment, work permits, prevention measures, explosion/deflagration venting, suppression systems as well as usual reviews conducted as part of the RRFSO.