Understanding how dust explosions happen
The HSE explains a dust explosion as the rapid combustion of dust particles that releases energy and usually generates gaseous reaction products.
A dust explosion requires only three things: air, combustible dust and a source of ignition. Dust explosions can vary in size but in extreme circumstances can result in death or serious injury to employees and the destruction of buildings. In some cases a fireball can form, as well as secondary explosions and widespread fire.
Many everyday materials produce dusts that are flammable and in the form of a cloud can explode, if they’re ignited. These include things like sugar, wood, coal, grain, some metals and a range of synthetic organic chemicals.
Dust explosions can be commonplace and occur in a wide range of manufacturing industries including pharmaceutical, food and paper.
Reducing the chances and impacts of a dust explosion
The Dangerous Substances and Explosive Atmospheres Regulations require employers to make an assessment of the health and safety risks arising from dangerous substances, and this specifically includes dusts which can explode.
There are four main ways you can reduce the risk of dust explosions:
- By altering the process so that dust particulates are coarser and less explosive
- By adding screens or walls to limit the spread of dust or the spread of an explosion
- By identifying and reducing possible sources of ignition
- By reducing the accumulation of dust
When dust accumulates in the air and on surfaces it increases the risk of a dust explosion happening. When a dust explosion does occur, it can stir up dust that has settled on surfaces throughout the facility, causing a new cloud and subsequent secondary explosion. By keeping dust to a minimum it can reduce this risk. Manufacturers should also aim to keep dust in the air to a minimum as not only does it reduce the risk of dust explosions, but also protects workers’ health by increasing the air quality.
Segregating the facility with dust partitions, either temporarily or permanently, can help businesses overcome short or long-term dust control requirements. These partitions can stop the spread of dust from one area to another making it easier to maintain standards.
For example, Flexiwall is permanent partition wall manufactured from fire rated PVC fabric materials, which is suspended and tensioned to form a permanent but reconfigurable, relocatable or removable partition wall. It offers an over 99% dust tight seal making it a highly effective solution for dust containment. Additionally, should a dust explosion occur, having adequate segregation within your facility can contain the impact of the explosion to a limited area.
Additionally, Flexicurtain is a retractable curtain that can also contain dust in one particular area. Whilst not as dust-tight as Flexiwall, it provides temporary segregation and can be put away when not needed for complete flexibility.