In many manufacturing industries specifically chemical and plastics manufacturing, hazardous-location compliance is often reduced to one question:
Is the equipment explosion-proof?
That is an important question, but it is not the first one that needs to be answered.
Before equipment can be selected, the facility must understand where a hazardous atmosphere could exist, what material could create it, how frequently it could occur, and how far that atmosphere could travel.
In other words, compliance starts with the hazardous-location classification, not the equipment catalogue.
A New Manitoba Electrical Code Is Now in Effect
On April 1, 2026, the 2024 Canadian Electrical Code came into force in Manitoba. It is enforced through the Manitoba Electrical Code Regulation and, within Winnipeg, the Winnipeg Electrical By-law.
For chemical and plastics facilities, this matters because modifications made to processes, ventilation, storage, or production equipment can affect the classification of the surrounding area.
A facility may not need to renovate an entire building for electrical requirements to become relevant. Adding a solvent-based process, relocating a mixing station, modifying an exhaust system, or installing new injection moulding equipment can trigger a review of the hazardous location and the electrical equipment installed within it.
Winnipeg’s Requirements Go Beyond Spray Booths
A City of Winnipeg information bulletin issued in April 2026 addresses painting and coating operations, but its scope is much broader than the title suggests.
The bulletin specifically includes:
- Fiberglass operations
- Injection moulding
- Mixing and manufacturing
- Dipping and coating
- Storage and handling
- Processes involving hazardous, flammable or combustible liquids, solids and gases
The City identifies these as high-hazard industrial operations and states that the requirements apply regardless of the operation’s size or complexity.
For applicable projects, the City requires a sealed engineered report or plan showing:
- The location of electrically hazardous areas
- The classification assigned to each area
- The extent of each classified boundary
- How the electrical installation complies with that classification
Electrical and mechanical trade permits may also be required, along with coordinated building, ventilation, fire-protection, and electrical documentation.
That means a small process change can create a much larger compliance obligation than facility teams initially expect.
Source: City of Winnipeg – Painting and Coating Operations Bulletin (April 2026)
https://www.winnipeg.ca/media/6152
Class I, Division 1 or Zone 1?
The terms are related, but they should not automatically be treated as interchangeable.
For many years, hazardous locations in Canada were classified using the Class and Division system (such as Class I Division 1 or Class I Division 2), and many existing industrial facilities still use these classifications.
While these installations remain compliant, the Zone classification system has become the modern standard under the Canadian Electrical Code for new installations because it aligns with international IEC standards and provides a more accurate assessment of risk. Rather than simply identifying whether a hazardous atmosphere is present during normal or abnormal operation, the Zone system classifies areas based on how frequently an explosive atmosphere is expected to exist.
In addition to the Zone designation, equipment must also be selected based on the appropriate gas or dust group and temperature class to ensure it cannot ignite the surrounding atmosphere.
As a result, technicians should still understand the legacy Class/Division system for maintaining existing facilities, but they should expect most new projects, equipment, and engineering designs to use the Zone classification system.
Class I hazardous locations contain flammable gases or vapours that may be present in sufficient quantities to produce explosive or ignitable mixtures in the air. These are commonly found in oil and gas facilities, refineries, fuel storage terminals, chemical plants, paint spray operations, and natural gas compressor stations.
Under the legacy Class/Division system, these locations were further divided into Division 1 and Division 2 based on the likelihood of the hazardous atmosphere being present. Today, new Class I installations are typically classified using the Zone system (Zones 0, 1, and 2).
Class II hazardous locations contain combustible dust that can become suspended in the air and ignite or explode. Dust hazards are commonly encountered in grain elevators, flour mills, woodworking facilities, coal handling plants, plastics manufacturing, and other industrial processes that generate fine combustible dust.
When dust accumulates on equipment or becomes airborne, it can create a significant explosion hazard. New installations are generally classified using Zones 20, 21, and 22 instead of the older Division system.
Class III hazardous locations contain easily ignitable fibres or flyings, such as cotton, flax, hemp, sawdust, or similar materials. Unlike combustible dust, these fibres are generally too large to remain suspended in the air as an explosive cloud but can accumulate around electrical equipment and ignite if exposed to sparks or hot surfaces.
Class III hazards are commonly found in textile mills, woodworking facilities, paper processing plants, and similar industries. Modern installations typically address these hazards using the IEC dust classification system where applicable.
Division 1 describes a hazardous location where an explosive gas, vapour, or combustible dust is expected to be present during normal operating conditions, or where maintenance, repair, or equipment failure could frequently release a hazardous atmosphere.
Electrical equipment installed in Division 1 areas must be capable of operating safely while the hazardous atmosphere is present. Under the modern Zone system, Division 1 generally corresponds to Zone 0 or Zone 1 for gases and Zone 20 or Zone 21 for combustible dusts, depending on how frequently the hazard exists.
Division 2 describes a hazardous location where hazardous gases, vapours, or combustible dusts are not normally present during regular operation but may appear because of abnormal conditions such as equipment failure, leaks, or accidental releases. These areas present a lower probability of ignition than Division 1 but still require appropriately rated electrical equipment. Under the modern Zone system, Division 2 generally corresponds to Zone 2 for gases and Zone 22 for combustible dusts.
Canada now uses the three-zone system for new installations:
- Zone 0 is the highest level of gas hazard and identifies an area where an explosive gas atmosphere is present continuously, frequently, or for long periods of time. Typical examples include the interior of fuel tanks, process vessels, and other enclosed equipment containing flammable gases or vapours. Equipment installed in Zone 0 requires the highest level of protection because ignition could occur during normal operation at any time.
- Zone 1 identifies an area where an explosive gas atmosphere is likely to occur during normal operation, but only occasionally. Examples include areas around pump seals, loading connections, relief valves, and process equipment where flammable gases may be released as part of normal operation. Equipment used in Zone 1 must be designed to prevent ignition whenever these expected releases occur.
- Zone 2 identifies an area where an explosive gas atmosphere is not normally present during regular operation and, if it does occur, will exist only for a short period due to an abnormal event such as a leak or equipment failure. This is one of the most common hazardous classifications in industrial facilities because many gas systems are normally sealed. Electrical equipment must still be suitable for the possibility of occasional hazardous atmospheres.
- Zone 20 identifies an area where a combustible dust cloud is present continuously, frequently, or for long periods. Typical examples include the interior of dust collectors, silos, bins, and powder processing equipment. Since combustible dust is expected to be present as part of normal operation, equipment installed in Zone 20 requires the highest level of dust ignition protection.
- Zone 21 identifies an area where a combustible dust cloud is likely to occur during normal operation. These locations are commonly found around conveyor transfer points, bagging equipment, hoppers, and processing machinery where dust is routinely released during production. Electrical equipment must prevent ignition whenever these expected dust releases occur.
- Zone 22 identifies an area where combustible dust is not normally present during regular operation, but may become airborne under abnormal conditions such as equipment failure, accidental spills, or inadequate housekeeping. Zone 22 is commonly found in the general areas surrounding dust-producing equipment. Although the likelihood of a hazardous dust cloud is low, appropriately rated equipment is still required to prevent ignition if such conditions arise.
Existing facilities may still have drawings and equipment marked using the Division system. However, a new installation or process modification should not simply reuse a historic “Class I, Division 1” label without confirming how the current Manitoba Electrical Code applies.
Source (hazardous location definitions): CSA Group – Hazardous Locations Overview
https://www.csagroup.org/en-gb/services/ex-product-certification-approvals/csa-north-american/definition-for-hazardous-locations-product-certification-in-north-america/
The Boundary Is as Important as the Classification
A hazardous location drawing should not simply identify an entire room as hazardous unless the engineering assessment determines that the entire space is classified. Instead, it should define the classified envelope surrounding each potential source of release. These boundaries are established through an engineering hazard assessment and identify where an explosive gas, vapour, or combustible dust atmosphere may exist under the expected operating conditions.
Examples can include:
- Tank vents
- Solvent dispensing stations
- Mixing vessels
- Resin application equipment
- Transfer pumps
- Fill and drain connections
- Sample points
- Spray or coating equipment
- Process exhaust outlets
- Areas where flammable liquids are stored or transferred
The distance and direction of the boundary can be influenced by the material, process pressure, release rate, room geometry, ventilation, and whether vapour can migrate through openings, trenches, drains, or conduit.
This is why moving a process skid by several metres or changing ventilation is not always a simple operational adjustment. It can move the hazardous boundary over equipment that was never selected for that environment.
Three Details Commonly Missed During Equipment Reviews
1. The gas group must match the material
A piece of equipment marked for a hazardous location is not automatically suitable for every flammable gas or vapour.
Equipment must be approved for the gas group associated with the material present. A motor, sensor, luminaire, junction box, or instrument may be suitable for one group but not another.
The facility’s chemical inventory and safety data sheets should support this determination, but the final classification must account for the actual process conditions.
2. The temperature code matters
Hazardous-location equipment is assigned a temperature code based on its maximum surface temperature.
The equipment’s maximum surface temperature must remain below the ignition temperature of the gas or vapour present. The City of Winnipeg’s electrical design guidance also cautions that equipment installed in an ambient temperature above its rating may have a higher actual surface temperature.
A correct enclosure rating does not compensate for an incorrect temperature code.
3. Vapour can migrate through wiring systems
Hazardous vapours do not necessarily stop at a wall or at the edge shown on a floor plan.
Conduit and cable systems can provide a pathway into an unclassified area, control panel, or electrical room. Proper sealing at classified boundaries is intended to limit that migration.
A seal that is missing, improperly located, incorrectly filled, or disturbed during later maintenance can compromise the original protection strategy even when the connected equipment is correctly rated.
Ventilation Is Part of the Electrical Compliance Strategy
Ventilation can influence whether an area is classified as Zone 1, Zone 2, or unclassified. However, ventilation should not be used as an informal reason to downgrade an area.
The system’s capacity, reliability, discharge location, failure response, alarms, interlocks, and operating conditions all need to be considered.
Winnipeg’s electrical design guidance notes that engineered ventilation, combined with appropriate failure protection, may allow a Zone 1 area to be classified as the less severe Zone 2. That can simplify maintenance and equipment selection, but only when supported by engineering analysis and documented controls.
If the electrical classification depends on ventilation, the ventilation system itself becomes part of the facility’s safety case.
Source (Manitoba electrical technical guidance):
https://www.hydro.mb.ca/docs/permits/technical-interpretations-v0626.pdf
A Practical Compliance Check
Chemical, petrochemical, plastics, and other hazardous-process facilities should be able to readily produce the following documentation without having to reconstruct it during an inspection or audit:
- A current hazardous area classification report prepared or reviewed by a qualified professional engineer.
- Hazardous area classification drawings showing classified boundaries, Zones or Divisions, release points, and the extent of each classified area.
- Documentation identifying the flammable gases, vapours, liquids, or combustible dusts used to determine each classification.
- The applicable gas or dust groups, ignition properties, and required equipment temperature classes.
- Equipment schedules or certification records demonstrating that installed electrical equipment is approved for the applicable hazardous location.
- Conduit and cable sealing details, including sealing fittings and methods used to prevent the migration of hazardous atmospheres.
- Ventilation design criteria, assumptions used during the classification, and any associated ventilation monitoring or failure interlocks where required.
- Electrical permits, inspection records, and documentation of acceptance or commissioning where applicable.
- Records of process, equipment, or facility modifications that could affect the hazardous area classification.
- A documented management of change (MOC) or engineering review process to evaluate modifications that may alter the hazardous area classification.
If these records are missing, outdated, or inconsistent with current operating conditions, the facility may not be able to demonstrate that the installed electrical equipment remains suitable for the actual hazardous environment. Changes to equipment, processes, chemicals, ventilation, or facility layout should always be reviewed to determine whether the hazardous area classification remains valid.
The Most Important Question
The question is not simply:
“Do we have explosion-proof equipment?”
It is:
“Can we demonstrate that every electrical component within the classified boundary is suitable for the material, gas group, temperature, zone, and operating conditions present today?”
That is the difference between having hazardous-location equipment and having a defensible hazardous-location compliance program.
Know Your Boundaries Before They Become Your Risk
MAKA Power helps facilities assess hazardous-location electrical systems, identify documentation gaps, test critical equipment, and build a clearer long-term compliance and maintenance strategy.
Request a Hazardous-Location Electrical Review
This article provides general information and does not replace a site-specific classification completed by a qualified professional or direction from the applicable authority having jurisdiction.
Regulatory references:
- City of Winnipeg Electrical / Building Code information:
https://www.winnipeg.ca/building-development/building-renovating/construction-codes-bylaws/enforced-construction-codes - City of Winnipeg April 2026 bulletin (Painting & Coating Operations):
https://www.winnipeg.ca/media/6152 - Manitoba Workplace Safety and Health Regulation (Part 19):
https://web2.gov.mb.ca/laws/regs/current/217-2006.php?lang=en - CSA Hazardous Locations Certification Overview:
https://www.csagroup.org/en-gb/services/ex-product-certification-approvals/csa-north-american/definition-for-hazardous-locations-product-certification-in-north-america/
