Combustible dust hazards can exist anywhere in the world. The technical definitions for combustible dust vary. In Canada, the Hazardous Products Regulation (WHMIS 2015) defines combustible dust as " a mixture or substance that is in the form of finely divided solid particles that, upon ignition, is liable to catch fire or explode when dispersed in air". Another example is Alberta's Occupational Health and Safety Code which defines combustible dust as:
"A dust that can create an explosive atmosphere when it is suspended in air in ignitable concentrations."
Essentially, a combustible dust is any fine material that has the ability to catch fire and explode when mixed with air. Combustible dusts can be from:
Some of these materials are not "normally" combustible, but they can burn or explode if the particles are the right size and in the right concentration.
Therefore any activity that creates dust should be investigated to see if there is a risk of that dust being combustible. Dust can collect on surfaces such as rafters, roofs, suspended ceilings, ducts, crevices, dust collectors, and other equipment. When the dust is disturbed and under certain circumstances, there is the potential for a serious explosion to occur. The build-up of even a very small amount of dust can lead to serious damage.
Regulation of this manufacturing danger is typically done on a country-specific basis. In Canada, occupational health and safety (OHS) matters are regulated according to 14 jurisdictional authorities: 1 federal, 10 provincial, and 3 territorial. Only about 6% of the population is covered under the federal regulations — federal employees as well as those who work for certain companies that operate across provincial borders. The remaining 94% fall under provincial or territorial regulations, depending on where they work. The rules in Canada are similar to those in the United States — the Canadian Centre for Occupational Health and Safety often follows US OSHA recommendations for worker safety. But, just like in the States, there are some differences between jurisdictions.
Learn more from this Combustible Dust Fact Sheet from the Canadian Centre for Occupational Health and Safety.