Updated August 2016
Combustible dust isn’t just a U.S. problem! While OSHA removed a combustible dust standard from their regulatory agenda, other countries are taking their own approach to regulating this clear and present manufacturing danger.
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 OSHA recommendations for worker safety. But, just like in the States, there are some differences between jurisdictions.
This article provides a comprehensive look at the different Canadian jurisdictions’ OHS laws related to combustible dust.
This section covers work involving any equipment that could provide an ignition source in any area that might contain combustible dust in a sufficient quantity to be a fire or explosion risk. It requires the area where the work is performed, as well as any surrounding areas within reach of an ignition source, to be “substantially free of combustible dust.”
Learn more from this Combustible Dust Fact Sheet from the Canadian Centre for Occupational Health and Safety.
**Note: This code recently went through a review process, and an updated version should be coming out soon.
Part 10: Fire and Explosion Hazards
Alberta supplies the following definitions related to combustible dust:
- Combustible dust is “a dust that can create an explosive atmosphere when it is suspended in air in ignitable concentrations.” Combustible dust is also recognized as a “flammable substance.”
- A hazardous location is “a place where fire or explosion hazards may exist due to flammable gases or vapours, flammable or combustible liquids, combustible dust, or ignitable fibres or flyings, as described in the Canadian Electrical Code.”
Section 165: Protective procedures and precautions in hazardous locations
Employers must ensure that:
- Equipment used will not ignite a flammable substance
- Static electricity is controlled
- Boundaries of the hazardous location are clearly defined and access is restricted
- Procedures are in place to prevent the release of a flammable substance or oxygen gas, when possible
- Measures are taken to prevent an explosive atmosphere from igniting
Section 169: Hot work
Hot work is not permitted until:
- The location is either cleared of or “suitably isolated from” combustible materials, AND
- “Testing shows that the atmosphere does not contain the minimum ignitable concentration for dust.” This testing must be repeated at regular intervals.
Part 36: Mining
Section 601: Combustible dust
This section states that in hazardous locations, combustible dust should not be allowed to accumulate “at or near the conveyor belt, the belt support rollers, the conveyor belt drive and tail, or the belt take-up drums.” If dust poses a hazard, the belt conveyor discharge must be constructed so as to minimize or eliminate the amount of dust spilled or dispersed into the air.
Part 5: Chemical and biological substances
Section 5.71: Flammable air contaminants
This section requires a separate exhaust ventilation system for any work that may produce combustible or flammable air contaminants in concentrations great enough to present a risk of fire or explosion. It also sets specifications for dust collectors used to control combustible dust.
Section 5.81: Combustible dust
“If combustible dust collects in a building or structure or on machinery or equipment, it must be safely removed before accumulation of the dust could cause a fire or explosion.”
Part 8: Confined spaces
Section 9.9 Hazard assessment
Hazard assessments — including an assessment of combustible dust — must be conducted for all confined spaces as well as work activities performed within confined spaces.
Part 22: Underground workings
This policy set requirements for any work done underground. In particular, it limits the amount of exposure a worker may have to respirable combustible dust and specifies regulations for dust control during mechanical excavation. Additional safety measures may be required in any environment containing combustible dusts in quantities sufficient to present a fire/explosion hazard.
Policies Workers Compensation Act Part 3 Division 3 – General Duties of Employers, Workers, and Others
This document details requirements for mitigating and controlling combustible wood dust, specifically in sawmills, pulp and paper mills, and similar industrial settings.
For employers, WorkSafeBC outlines the following “reasonable steps to address the hazards of combustible wood dust”:
- Conducting a risk assessment to identify hazards
- Developing and implementing a combustible wood dust management program
- Educating employees about the program
- Ensuring the program is fully implemented
- Performing an audit of the program
- Reviewing the program annually
- Complying with the program
OHS Guidelines Part 4: General Conditions
Section 4.42(1): Cleaning with compressed air – Hazards of combustible dust
Compressed air is a common cleaning procedure in industrial applications. However, when combustible dust is present, compressed air can pose a heightened risk of combustible dust incidents by dispersing the dust into the air.
This guideline recommends that, while cleaning with compressed air is permitted, it “should be minimized…and should only be done where other methods of cleaning are not practicable.” The guideline identifies four necessary controls for managing combustible dust:
- Minimizing dust through sweeping and/or vacuuming
- Minimizing dispersion by washing with water if possible and using compressed air only in localized or isolated areas
- Eliminating sources of ignition by allowing machines to cool, locking out equipment, and controlling static
- Ensuring fire protection equipment is available in case of emergency
Manitoba’s definition of flammable substance includes “dust that is capable of creating an explosive atmosphere when suspended in air in concentrations within the explosive limit of the dust.”
Part 19: Fire and explosive hazards
This is the main part of Manitoba’s code that deals with flammable substances, including combustible dust. In particular, it specifies that workers should not enter an area “where a flammable or explosive substance is present in the atmosphere at a level that is more than 10% of the lower explosive limit of that substance” and recommends the precautions that must be taken to prevent fire and explosive hazards.
“Where work is carried out in an area where dust may create a hazard to the health of employees, an employer shall take such measures with respect to the dust as are sufficient to protect employees from the risk of damage to health.”
Industrial lift trucks
Industrial lift trucks may not be operated near areas containing explosive dusts.
Section 263, 267, and 268
Confined spaces must be tested to verify that the concentration of airborne dust isn’t high enough to pose a hazard. Specifically, the dust in the confined space may not exceed 50% of its lower explosive limit.
This section limits the types of work permitted in areas where airborne dust is present to inspection, cleaning, and cold work with non-sparking equipment.
Finally, this section details the circumstances under which respiratory protective equipment is required.
Welding, cutting, burning, and soldering
Section 275(1) and 275(2)
No welding, cutting, burning, or soldering may be conducted until the surrounding area has been inspected to ensure that all combustible, flammable, or explosive materials (including dust) have been removed.
Newfoundland and Labrador
Section 446: Combustible substances
This section requires effective dust control equipment in any enclosed area where combustible dust is present.
- Dust collectors must be located outside or in isolated enclosures and provided with explosion relief vents.
- Electrical wiring equipment must be explosion-proof.
- Combustible dust must be removed from buildings, structures, machinery, and equipment before it accumulates to the point of creating a fire or explosion hazard.
Northwest Territories and Nunavut
Sections 23 to 29
This section outlines general housekeeping requirements, including the guideline to keep work areas clear of hazards.
Welding and burning
Several parts of this code address hot work. Section 167 specifies that no hot work should be carried out in areas likely to contain a flammable or explosive substance until:
- Safety tests have been performed.
- Suitable procedures have been adopted to ensure safe performance of the work.
- Suitable procedures have been adopted to eliminate or control potential sources of ignition.
The use of explosive-actuated tools is prohibited in areas where flammable or explosive dust is present.
Part 10: Welding, Cutting, Burning, and Soldering
Before undertaking hot work, the person operating the equipment must ensure that all hazardous materials or processes that could produce combustible dust are removed from the area.
Explosive-actuated fastening tools should not be used in an atmosphere containing flammable dusts.
Precautions must be taken before performing any processes likely to produce dust capable of forming an explosive mixture with air.
Equipment must be protected against the entry of foreign particles that could cause a dust explosion.
Prince Edward Island
Part 5: Housekeeping – General Provisions
Combustible materials should not be allowed to accumulate where they would constitute a fire hazard.
Part 37: Welding
Welding and cutting are prohibited in areas containing combustible materials or in the close proximity of explosive or flammable dusts unless adequate precautions are taken to prevent fires or explosions.
Division VIII: Combustible dusts and dry materials
Section 54: Preventive cleaning
All rooms where combustible dusts are generated should be cleaned as often as possible to prevent hazardous accumulation.
Section 55: Static electricity
In areas where combustible dust is present, all metallic equipment must be grounded and non-metallic equipment must be built and installed to prevent static electricity.
Section 56: Flammable source
No flammable sources are permitted in areas containing combustible dusts that present a hazard.
Section 57: Fire or explosion hazard
Measures must be taken to protect employees near machines and equipment that present a hazard due to combustible dusts.
Section 58: Collection and processing systems
All collection and processing systems for combustible dust and other material containing a fire or explosion hazard must be built according to the appropriate NFPA standards.
Section 59: Dust collectors
These two sections provide detailed requirements for the construction and installation of dust collectors.
Division XXVII: Welding and cutting
Section 313: Prohibition
Welding and cutting are prohibited close to places containing combustible dust that presents a hazard unless special precautions are taken.
Part XXV: Fire and explosion hazards
Saskatchewan’s definition of flammable substance includes “dust that is capable of creating an explosive atmosphere when suspended in air in concentrations within the explosive limit of the dust.”
Section 363: Procedures for flammable substances
Employers must develop written procedures for handling flammable substances and ensure that all workers who perform hot work are trained in these procedures.
Section 367: Control of ignition sources, static charges
Suitable procedures must be developed and implemented to prevent the ignition of explosive dusts.
Section 370: Hot work
No hot work should be performed until the atmosphere has been tested to confirm it’s safe.
Part 13: Trades and miscellaneous
Section 13.12 Fire prevention
Welding, cutting, burning, or soldering should not be performed unless the area has been inspected to ensure all combustible dust has been removed or other measures have been taken to prevent fire or explosion.
Part 15: Surface and underground mines or projects
Section 15.34 Processes likely to produce flammable mixtures
A process likely to produce dust capable of forming a flammable mixture with air must be isolated, ventilated, and have no potential sources of ignition. In addition, measures must be taken to reduce the effects of an explosion.
An appropriate separate ventilation system is required wherever an operation or work process produces combustible or flammable dusts in concentrations that exceed the lower explosive limit of that substance.
And that’s a wrap! We’ll do our best to keep this article updated as new regulations come on the books. So, if you’re involved in Canada’s manufacturing and industry, be sure to check back often!