What types of dust are explosive?
What are examples of materials that can be a combustible dust hazard?
- agricultural products such as egg whites, powdered milk, cornstarch, sugar, flour, grain, potato, rice, etc.
- metals such as aluminum, bronze, magnesium, zinc, etc.
- chemical dusts such as coal, sulphur, etc.
- pharmaceuticals.
- pesticides.
- rubber.
- wood.
What causes a dust explosion?
Dust explosions are the result of high concentrations of combustible dust particles rapidly combusting inside an enclosed space. When mixed with oxygen, these fine particles can be ignited when coming into contact with a spark, metal ember, cigarette butt, or other ignition source.
What NFPA 652?
The National Fire Protection Association (NFPA) 652, Standard on the Fundamentals of Combustible Dusts, provides general requirements for the management of combustible dust fire and explosion hazards and directs the user to appropriate NFPA industry or commodity-specific standards.
Where do dust explosions occur?
Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere or other oxidizing gaseous medium, such as pure oxygen. In cases when fuel plays the role of a combustible material, the explosion is known as a fuel-air explosion.
Is dust flammable or combustible?
Any combustible material can burn rapidly when in a finely divided form. If such a dust is suspended in air in the right concentration, under certain conditions, it can become explosible.
How strong is a dust explosion?
They vary from 10 grams per cubic metre to about 500 grams per cubic metre. For most practical purposes it may be assumed that 30 grams per cubic metre is the lower explosive limit for most flammable dusts.
How can dust explosion be prevented?
To prevent a dust explosion, OSHA recommends employers: Implement a hazardous dust inspection, testing, housekeeping and control program. Regularly inspect for dust residues in open and hidden areas. If ignition sources are present, use cleaning methods that do not generate dust clouds.
What are the 5 requirements for an explosion?
THE FIVE ELEMENTS OF COMBUSTIBLE DUST EXPLOSIONS
- Combustible Dust.
- Distribution Of Dust Particles.
- Confined Dust Cloud.
- Oxygen.
- Ignition Source.
What is a secondary dust explosion?
Secondary explosions occur when there is a rapid combustion of fine combustible dust particles suspended in the air. Secondary dust explosions can occur where any combustible material in dust form is suspended in the atmosphere in a high enough concentration that allows combustion with a source of ignition.