Our safety culture has changed significantly over the years regarding dust hazards and dust collection systems. This can be attributed to tragic events such as explosions and fires that have prompted education and a better understanding of the hazards posed by combustible dust. This has led to changes in regulatory safety codes, a questioning attitude among employees, and closer examination and enforcement by fire prevention officers and other code enforcement authorities.
Dust collection systems are essentially safety systems, as they should remove fine, volatile dust from operations and help prevent hazardous dust accumulations in buildings. Although they provide a safety function, collecting combustible dust is hazardous, and protection measures are needed to safeguard workers and operations.
When dealing with dust collection systems, the National Fire Code of Canada and other provincial Fire Codes require protection for your dust collector. The National and Provincial Fire Codes may provide different levels of protection. The National Fire Code of Canada and other provincial Fire Codes also specify a vent area of 0.1 m2 for each cubic meter of dust collector enclosure volume. This does not align with the standard on explosion protection by deflagration venting (NFPA 68), which these codes also reference. Venting will protect the equipment but will not necessarily prevent deflagrations from spreading back into the building or to connected equipment. As you can see, determining the required protection for dust collectors can be difficult and may not be adequate if you rely solely on local codes.
If your facility has a Dust Collector, protection measures are needed to protect workers and the operations.
At PLC, a Jensen Hughes Company, we focus not only on local fire code requirements but also on understanding the processes and materials handled when examining dust collection systems. Not all materials are the same, and not all processes that handle or create dust are equally hazardous. Some hazardous processes may require spark detection and extinguishing systems, sprinkler protection, and explosion protection. To determine the protection required for your dust collector, several factors should be considered. Below is a list of some common factors:
- Dust collector location (indoors or outdoors);
- Material(s) being handled (e.g., wood dust, starch, coal dust, titanium dust);
- Process hazards and possible ignition sources;
- The dust collection unit design in terms of strength and volume.
- Connected equipment and if exhaust air is returned to the building; and
- Exposure potential to building personnel or the public when using venting.
The National Fire Protection Association (NFPA) has many standards that provide guidance on assessing combustible dust hazards, detailing protection requirements based on the type of facility and hazardous operations (e.g., woodworking, agricultural, metal dust, etc.) and requirements for designing effective explosion protection systems. All the factors listed above, and more, are addressed in these NFPA standards. Compliance with the appropriate NFPA standards for protecting your dust collection systems will not only meet the intent of local Fire Codes but also ensure that your building occupants are safe and that your process is protected from long-term interruptions and significant financial losses.
Please contact us if you have any questions or concerns regarding your dust collection systems.