Many manufacturing processes create dust, and dust as we all know gets everywhere, as anyone who has ever had any re-plastering done in their home. Work carried out in one part of the building will result in the appearance of a fine layer of dust in just about every other room, even in cupboards. In the industrial environment, over 80% of conventional materials used are combustible, so consequently any dust created in this situation, and liable to migrate, is classed as hazardous. In the industrial landscape dust will settle in machine rooms, hidden spaces, roof rafters and even in and around dust collection systems.
In the right conditions, free floating dust has the potential to explode causing not only damage to machinery and premises but significant injury and even death.
Hazardous Dust Created During Manufacturing Processes
It is a surprising fact however that many organisations are unaware of the extent of this threat, as dust can be produced by a small and inconsequential stage in the manufacturing process. Globally, there are numerous examples of this over the years, for instance in 1997 at a French grain store a dust explosion caused fatalities. This also happened in a rubber manufacturing plant in North Carolina, USA, in 2003, after an explosion which was the result of a hidden accumulation of plastic dust. More recently in 2014, a devastating explosion in a Chinese factory was traced back to metal dust produced by polishing steel hub caps.
In the UK and Europe, there are stringent measures in place to prevent these occurrences, making them fairly rare, yet dust related explosions remain a huge cause for concern. The regular damage and loss brought about by these explosions rising from airborne dust and subsequent fires, serves to highlight the serious nature of the problem.
What Causes a Dust Explosion?
There are certain conditions and risk factors which make it highly likely that an explosion may happen, these include:
- Combustible dust
- Dust becoming airborne
- Combustion being enabled by dust particle size
- Dust being concentrated within the materials explosion limits
- The introduction of an ignition source
- Sufficient oxygen content to support combustion
When the dust ignites, pressure rises swiftly especially in an enclosed space, the ensuing blast usually stirs up other dust deposits, allowing a secondary, more significant explosion to occur.
This type of dust explosion is common were certain materials are processed including flour, starch, animal feed, wood, paper, plastic, coal, pesticides, rubber, textiles, metal, pharmaceuticals and dyes.
Health & Safety Requirements for Control of Explosive Dust in the Atmosphere
Minimum health safety requirements were set out in the Dangerous Substances and Explosive Atmospheres Regulations 2002. Intended to protect against exposure to explosive atmospheres these regulations place an obligation on employers to take action to limit all risk of dust explosion.
It is the responsibility of employers to identify potential hazards and possible causes of dust explosion, to assess and take steps to lessen the chance of this happening and to minimise any impact should this occur. Records are required to be kept outlining preventative actions taken, which should include:
- Elimination of sparks
- Dusty operations and dust producing equipment isolation
- Placing of explosion vents
- Foreign [tramp] material elimination
- Adequate earthing of equipment and accessories
Though very rare in the UK, the risk of a dust explosion is taken very seriously by many industries, who have seen the relevant data.
Along with fire prevention and control measures such as sprinkler system installation, appropriate extinguishers and accessories, we offer professional in depth fire risk assessments, fire awareness and various training courses. We can also recommend the installation of Unimatic Dust Collection Units. These reverse pulse jet, compressed air, industrial dust collection units, feature a versatile modular design and are manufactured in the UK. Unimatic LEV, filtration units also have an incredibly fast turn around of 4-6 weeks for bespoke models, with standard units available in only 7-10 days.