Handling flammable liquids in the workplace is more than just following rules—it’s about keeping people safe. 

In Canada, flammable liquid safety is a serious concern. According to Alberta’s Occupational Health & Safety bulletin, improper handling of solvents and other flammable liquids contributes to a significant number of fires and even explosions each year. 

With vapours that ignite easily, even small spills can turn dangerous. That’s why WHMIS (Workplace Hazardous Materials Information System) and workplace training are essential tools in prevention. 

WHMIS ensures every container is labelled with clear warnings and that workers know how to read Safety Data Sheets. The system also requires employers to offer site-specific training on flammable materials.

Coupled with regular drills and routine checks, good training empowers staff to recognize hazards before they turn into serious incidents.

In this article, we’ll dig into:

1. The key dangers of flammable liquids—from vapour ignition to static buildup
2. Important Canadian rules and codes that workplaces must follow
3. Practical tips on how to handle, store and dispose of flammable liquids safely

By the end, you’ll have a clear picture of how to keep your workplace safe, compliant and confident when working with flammable liquids. Let’s dive in!

What Are Flammable Liquids?

In Canada, flammable liquids are defined under WHMIS (Workplace Hazardous Materials Information System) using the Globally Harmonized System (GHS) of classification. 

A flammable liquid is any liquid that has a flash point below 93°C. The lower the flash point, the easier it is for the liquid to produce vapours that can ignite.

These liquids pose a high fire risk, especially in workplaces with poor ventilation or ignition sources nearby. 

Under WHMIS, flammable liquids fall under Category 1 to 4, with Category 1 being the most hazardous (flash point below 23°C and boiling point below 35°C).

Common examples found in many Canadian workplaces include:

1. Gasoline and diesel fuel
2. Alcohol-based hand sanitizers and cleaners
3. Paint thinners, varnishes, and lacquers
4. Solvents like acetone or toluene
5. Certain adhesives and degreasers

Workers must recognize these materials and understand the hazards associated with their storage and use.

Key Properties of Flammable Liquids

Two key characteristics make flammable liquids dangerous:

Flash Point

This is the lowest temperature at which a liquid gives off enough vapour to ignite in air. The lower the flash point, the higher the fire risk. For example, gasoline has a flash point around -40°C, meaning it can release ignitable vapours even at freezing temperatures.

Flammability Range

This refers to the concentration range of vapours in the air that can ignite. If vapour levels are within this range and there's an ignition source, fire or explosion can occur.

Why vapours are more dangerous than the liquid

Most flammable liquids themselves won’t burn unless they evaporate. The vapours are what catch fire. 

These vapours are often heavier than air and can travel far from the source, collecting in low spots or enclosed areas, where even a tiny spark can ignite them. That’s why spills—even small ones—need immediate attention.

Understanding these properties helps workers handle these substances with the caution they demand.

Why Are Flammable Liquids So Dangerous at Work?

Flammable liquids bring more than just a fire risk—they introduce multiple hazards that can threaten workers, property, and surrounding communities. 

Here’s why they’re so dangerous, and how real incidents show just how quickly things can go wrong without proper safety measures.

Fire and Explosion Risks

Flammable liquids release vapours that can ignite instantly when they meet sparks, static, open flames, or hot surfaces. Even electrical equipment like light switches or outlets can act as ignition sources. 

For example, when transferring liquids between containers, the build-up of static electricity can ignite vapours without warning. That’s why bonding and grounding are essential.

Ignition doesn’t require large amounts of liquid—small spills or residual vapours in confined spaces like cabinets or drains are enough to cause flare-ups or major explosions. 

Static discharge or a hot light bulb in an enclosed area can ignite a vapour cloud, causing rapid fire spread that can engulf entire workspaces.

Health Risks from Exposure

Apart from fires, exposure to flammable liquids can harm your body:

1. Respiratory issues: Breathing in vapours can irritate lungs, triggering coughing, dizziness, or shortness of breath—especially in poorly ventilated areas. Long-term exposure can even lead to chronic lung problems.
2. Skin and eye damage: Direct contact may cause dry, red, cracked skin or irritation. Eyes are vulnerable too—vapours and splashes can lead to redness, burning sensations, or even temporary vision issues.
3. Chronic effects: Over months or years, certain solvents are linked to neurological damage, liver or kidney problems, and reproductive harm. Even low-level exposure, repeated over time, can have serious, lasting consequences.

Real‑World Incidents in Canada

A recent case in Alberta illustrates the speed and severity of flammable liquid incidents. In 2022, an explosion at a Calgary oil‑and‑gas site injured multiple workers—charges were later filed against employers for safety lapses. 

In another case in 2023 (Quebec), workers entered a tar tank containing residue and began welding without purging it—vapours ignited, causing a fatal blast.

These incidents highlight how a missing purge, ignored training, or unseen ignition source can lead to explosions, severe burns, injuries, or even death—in just seconds. 

Without protocols like risk assessments, proper ventilation, bonding, and WHMIS-led training, what seems routine can turn catastrophic.

Understanding these three hazard categories—fire risk, health effects, and real-life cases—highlights the urgent need for robust safety practices, clear procedures, and ongoing employee training.

Best Practices for Handling Flammable Liquids

Working with flammable liquids requires strict attention to detail and safety procedures. The right habits can prevent fires, explosions, and health hazards. 

Below are essential best practices every Canadian workplace should follow when dealing with flammable substances:

General Safety Guidelines

1. Keep containers sealed when not in use: This reduces the release of flammable vapours and prevents accidental spills.
2. Avoid static discharge: Always bond and ground containers during transfer. Static electricity can easily ignite vapours, especially in dry indoor environments.
3. Use proper PPE: Wear gloves resistant to chemicals, safety goggles or face shields, and flame-retardant clothing if needed.
4. Never smoke near flammable liquids: This includes not just active smoking, but keeping lighters and matches far from storage and work areas.
5. Work in well-ventilated spaces: Use fume hoods or mechanical ventilation systems to ensure vapours don’t build up indoors.
6. Label all containers clearly: Use WHMIS-compliant labels that list hazards, precautions, and proper handling instructions.
7. Use only approved storage cabinets: Flammable storage cabinets must meet CSA/ULC standards in Canada and be kept away from heat sources.
8. Clean up spills immediately: Use absorbent materials rated for chemical use, and dispose of them in fire-safe containers.
9. Train employees regularly: All workers should receive WHMIS and site-specific training before handling any flammable liquids.

DOs and DON'Ts of Flammable Liquid Handling

DO:

1. Use anti-static tools and grounding wires when transferring liquids
2. Follow manufacturer and SDS (Safety Data Sheet) instructions
3. Store only small quantities at workstations—bulk storage should be elsewhere

DON’T:

1. Pour flammable liquids near heaters or energized machinery
2. Mix chemicals unless specifically instructed
3. Use open buckets or unlabelled containers

By building these habits into daily routines and reinforcing them through training and supervision, workplaces can greatly reduce the risks tied to flammable liquids. It’s not just about compliance—it’s about keeping everyone safe.

Safe Storage of Flammable Liquids

Storing flammable liquids the right way is just as important as handling them safely. Poor storage can turn a small incident into a major disaster—whether it's a spill, fire, or chemical reaction. 

In Canadian workplaces, storage must follow specific rules under WHMIS and provincial safety codes. These rules help minimize fire hazards, reduce health risks, and ensure quick emergency response if something goes wrong.

The goal is to isolate flammable liquids from ignition sources, limit vapour build-up, and prevent leaks or spills from spreading. Below are the key areas workplaces need to focus on for safe storage.

Storage Containers & Cabinets

Flammable liquids must be stored in approved safety containers, which are typically made of metal or high-grade plastic that won’t react with the chemicals inside. 

In Canada, these containers should be CSA (Canadian Standards Association) compliant and clearly labeled as flammable.

Larger volumes of flammable liquids should be stored in flammable storage cabinets, which are built to resist fire for up to 30 minutes. 

These cabinets should have self-closing doors, leak-proof sills, and venting options. Most importantly, they must be:

1. Located in designated areas
2. Fitted with clear signage (e.g., “Flammable – Keep Away from Heat”)
3. Equipped with proper ventilation to prevent vapour build-up

The cabinets should be kept away from workstations, stairways, exits, and electrical panels to minimize danger in case of fire.

Quantity Limitations & Segregation

In most jurisdictions, you cannot store large volumes of flammable liquids in open work areas. 

Occupational health regulations often limit storage to no more than 25 litres of Class 1A flammables outside of approved cabinets.

Bulk storage (for drums or large containers) should be in fire-rated storage rooms or detached buildings designed specifically for hazardous materials.

Also, flammable liquids should never be stored near incompatible materials. For example:

1. Acids and oxidizers should be stored separately from flammables
2. Cleaning chemicals, chlorine, and peroxides must be isolated
3. Fuels and compressed gases should be segregated using fireproof barriers

Use separate cabinets or clearly divided zones to ensure incompatible substances are always kept apart.

Temperature and Spill Control

Heat and ignition sources are major threats when it comes to storing flammable liquids. Always:

1. Store away from boilers, radiators, furnaces, or direct sunlight
2. Keep liquids in cool, dry areas that won’t fluctuate in temperature
3. Ensure that ambient temperatures stay well below the liquid’s flash point

To manage spills and leaks, every storage area should be fitted with secondary containment trays or sumps. These catch any drips or spills, preventing flammable liquids from spreading across the floor or reaching ignition sources.

Good practice also includes:

1. Routine inspection of containers and cabinets for corrosion or damage
2. Immediate cleanup of leaks using CSA-rated absorbent pads
3. Accessible fire extinguishers and spill kits nearby

When proper temperature control and spill containment are in place, workplaces can drastically lower the risk of serious incidents involving stored flammable liquids.

What to Do in Case of a Spill or Fire

Even with strong safety practices in place, accidents can still happen. A flammable liquid spill or fire can escalate quickly, putting workers, property, and the environment at risk.

That’s why every Canadian workplace that handles flammable materials must have a clear, well-communicated emergency plan.

Responding quickly and correctly can prevent injuries and minimize damage. These plans should include evacuation procedures, emergency contact information, access to safety equipment, and guidelines for reporting. 

Below are the two most important aspects of responding to a flammable liquid incident.

Immediate Response Steps

The first few minutes after a spill or fire are critical. Here’s what workers should do:

1. Evacuate the area immediately if there’s a fire or a large spill involving flammable liquids. Alert nearby workers and activate the facility’s emergency alarm.
2. Alert the emergency response team or supervisor. Do not try to manage a large fire or unknown chemical without training.
3. Use spill kits if the spill is small and you are trained to handle it. Kits should contain absorbent pads, neutralizers, and PPE.
4. Use the right type of fire extinguisher. For flammable liquids, only use a Class B or multi-class (ABC) extinguisher. Never use water—it can spread the liquid or cause a violent reaction.
5. Check the Safety Data Sheet (SDS) for that chemical. The SDS will tell you exactly what first aid steps to take, what PPE is required, and how to manage the cleanup safely.
6. If exposure occurs, use eyewash stations or safety showers immediately and seek medical help.

Training and regular drills are essential so employees stay calm and act quickly when these situations occur.

Spill Control and Reporting

Once the immediate danger is managed, the next step is proper spill containment, cleanup, and reporting. Canada has specific environmental and safety laws that guide this process.

Under the Canadian Environmental Protection Act (CEPA), certain spills must be reported to federal or provincial authorities—especially if the substance is on the CEPA toxic substances list or if the spill reaches water or soil.

Here’s what to do:

1. Follow your company’s internal protocols for incident logging and risk assessment.
2. Contain and clean the spill using absorbent materials and dispose of waste in CSA-approved hazardous waste containers.
3. Notify local environmental agencies or emergency response centres if the volume exceeds legal reporting thresholds. For example, Alberta’s Energy and Environmental Response Line or Ontario’s Spills Action Centre may need to be contacted.
4. Keep a record of the incident, actions taken, and communication with authorities.
5. Spill kits, SDS binders, emergency contact numbers, and a written response plan should all be easily accessible in any workplace where flammable liquids are used. 

Clear communication and compliance with reporting laws protect not just your team—but also your legal standing and the surrounding environment.

Common Mistakes to Avoid

Even in well-trained workplaces, small oversights can lead to major safety risks when handling flammable liquids. 

Many incidents in Canadian workplaces occur not due to lack of awareness, but because of routine shortcuts, poor habits, or failure to update procedures over time.

Avoiding these common mistakes can make a big difference in preventing fires, exposure, and regulatory violations.

Key Mistakes That Endanger Safety

1. Using old or unlabeled containers

Reusing bottles or jugs without proper WHMIS labels is a serious violation. If the contents are unknown or mislabelled, workers might unknowingly mix incompatible substances or apply incorrect cleanup methods in a spill.

2. Storing flammable liquids near electrical panels or heat sources

Liquids should never be stored near panels, heaters, furnaces, or welding stations. A single spark or heat surge could ignite vapours and cause an explosion.

3. Ignoring ventilation requirements

Flammable vapours are often heavier than air and can settle in enclosed areas. Poor ventilation allows vapours to build up and reach their flammability limit, making an ignition almost inevitable.

4. Overfilling containers

Leaving no space for vapour expansion in storage containers can lead to leaks, pressure buildup, or container rupture. Always fill containers only to the manufacturer’s recommended level.

5. Failing to ground and bond during transfers

When liquids are poured or transferred, static electricity can build up and ignite vapours. Using bonded and grounded equipment is essential for flammable liquid safety.

6. Storing incompatible chemicals together

Flammable liquids should be stored away from acids, oxidizers, and other reactive substances. Mixing these can cause dangerous chemical reactions.

7. Neglecting spill response plans

Not having updated spill kits or clearly posted emergency instructions can delay response times during incidents, increasing the risk of harm.

Avoiding these mistakes doesn’t require huge investments—just consistent training, regular safety checks, and a culture where safety is everyone’s responsibility. 

By being proactive, employers can reduce the risk of fire, injury, and legal penalties related to flammable liquid mishandling.

Training and Safety Programs Matter

One of the most effective ways to prevent fires, injuries, and environmental hazards involving flammable liquids is through proper training and safety programs. 

WHMIS (Workplace Hazardous Materials Information System) is the standard for ensuring that workers know how to safely handle, store, and respond to hazardous substances—including flammable liquids.

WHMIS training isn't just a one-time requirement. It must be:

1. Updated regularly (especially after a job change, new chemical introduction, or procedural updates)
2. Specific to the worksite and tasks being performed
3. Easy to understand, even for workers with language or literacy barriers

Why WHMIS Training Is Crucial

1. Prevention of incidents: A well-trained worker is less likely to make mistakes like using the wrong container, mixing incompatible substances, or ignoring ventilation needs.
2. Recognition of hazards: Workers learn how to read Safety Data Sheets (SDS) and WHMIS symbols, helping them identify fire and health risks before problems occur.
3. Proper PPE use: Training ensures workers know what gloves, goggles, or respirators are needed and how to use and maintain them correctly.
4. Emergency readiness: Training also covers what to do in case of a spill or fire, including evacuation procedures, how to use fire extinguishers or spill kits, and who to report to.

Employer Responsibilities

Under Canadian health and safety regulations, employers are legally required to:

• Provide initial and ongoing WHMIS training
• Ensure training includes site-specific procedures and emergency response plans
• Keep documentation and training records
• Review and update training when there are new hazards, tasks, or equipment

Workplaces that invest in regular safety training reduce not only risk but also downtime, compensation claims, and legal issues. 

When workers are confident in what to do—and employers show commitment to safety—everyone wins. Flammable liquids don’t have to be dangerous if handled by people who know what they’re doing.

Final Thoughts

Flammable liquids are a common part of many Canadian workplaces, but that doesn’t make them any less dangerous. From vapour fires to toxic exposure, the risks are real—and often preventable. 

Employers and safety professionals must understand the hazards, follow legal requirements, and commit to safe handling and storage practices every day.

We’ve covered the essentials: 

• How to identify flammable liquids
• Their health and fire risks
• Proper storage techniques
• Emergency response steps
• The importance of WHMIS training

Each of these areas plays a key role in reducing the chances of a serious incident.

If you’re responsible for workplace safety, now is a good time to review your flammable liquid protocols. 

• Are your containers properly labelled? 
• Are employees trained and confident in handling spills or using fire extinguishers? 
• Do you have clear reporting procedures in place?

Knowing how to handle flammable liquids in the workplace isn’t just a compliance issue—it’s a matter of protecting people, property, and the environment. Safety starts with awareness and ends with action. 

By staying informed and being proactive, you create a culture where everyone understands the risks and takes them seriously.

Keep your team trained, your procedures up to date, and your commitment to safety strong. It’s the best investment any employer can make.