Preventing Combustible Dust Explosions and Fires

Assessing the explosive properties of ‘dust’ allows you to fully understand the hazards that are in a place of work. This safety critical information will then allow you to be fully aware of the hazards in the workplace and help to then plan to prevent a fire and explosion.

The Health & Safety Executive statistics show that dust explosions are fortunately rare occurrences, however they do have the potential to kill and action must be taken to reduce or eliminate such hazards. The Health & Safety at Work Act 1974 and the Dangerous Substances and Explosion Atmospheres Regulations (DSEAR) 2002 are in place to ensure such safety in the workplace but are you fully aware of the duties these legislations bring?

Dust explosions can be classified as being either primary or secondary in nature. Primary dust explosions can be described as occurring inside a process plant orsimilar buildings. Pressure relief that can be seen in purpose-built ducting would normally control such an incident. Secondary dust explosions are the result of dust accumulation inside the plant which when disturbed and ignited by the primary explosion, can easily result in a much more dangerous uncontrolled explosion. It is the secondary explosions that have caused fatalities over the years.

In order to assess how you can prevent such an incident, injury or fatality you need to ask the following questions:

Have you had a sample of the dust tested?

Such a test would allow a company to fully understand the hazards that the dust holds and will impact on the control measures you decide to implement to reduce / eliminate risk.

Does the company have a thorough housekeeping / cleaning regime?

Good housekeeping is key to avoid a buildup of an Explosible dust but there are certain ways in which to do this safely. Knowing the information from the test will help towards a thorough assessment of the areas and appropriate measures can then be put in place.

If you can see it – you may already have a secondary hazard.

Is any dust leaking from a pipe, conveyor or other process?

The company must ensure that there is no dust build-up at all throughout the process plant. A goodmaintenance, inspection and hazard identification process must be implemented and adhered to by allemployees on site.

Have you had a site DSEAR Risk Assessment completed?

The assessor will take the test results and site information to then classify certain areas into zones. These zones will then indicate what control measures are required. The test results will show such information as the Explosion indices (Pmax & Kst), minimum ignition temperature (MIT), the layer ignition temperature (LIT), the lower explosion limit (LEL) and the minimum ignition energy (MIE).

If you do not know about this information then you may need to seek specialist advice.

For more information contact RADCaT Ltd: 01942 824635

Total Risk Management Specialists