Level 1, Unit 1, Section 1 – 1.3 Hazardous Materials

1.3.1 — Identifying Hazardous Materials

The following categories cover the major hazardous material groups you will encounter on the job. Recognizing each type at a glance allows you to select the correct PPE, consult the right SDS section, and apply the appropriate handling procedure before any work begins.

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Refrigerants

Classified by flammability and toxicity:

Non-flammable / Low toxicity: R-134a, R-410A — most common in residential & commercial systems
Non-flammable / Higher toxicity: Ammonia (R-717) — industrial systems
Flammable / Low toxicity: Hydrocarbons R-290, R-600a; CO₂ (R-744) under certain conditions
Flammable HFOs: Some newer low-GWP refrigerants have mild flammability

⚗️

Corrosive Chemicals

Acids for cleaning and maintenance
Alkaline cleaners and degreasers
Flux used in brazing

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Combustible Materials

Refrigerant oils
Solvents and cleaning agents
Acetylene and other fuel gases

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Toxic Products

Products containing lead or other heavy metals
Chemical refrigerants that decompose into toxic compounds when exposed to high heat or flame

⚠️

Carcinogenic Products

Some older insulation materials may contain asbestos
Welding fumes can contain carcinogenic compounds

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Biological Contaminants

Mould in air handling systems
Bacteria in cooling towers and drain pans

1.3.2 — Examples of Work Safety Incidents

Real-world incidents show what happens when hazardous material procedures break down. Study each case, the safety notes, and the exploration questions carefully — these are the kinds of scenarios a licensed mechanic must be able to prevent.

Incident 01

Ammonia Leak During System Dismantling

🏭 Industrial Refrigeration 📍 Kamloops, BC 💀 Fatal

A large industrial refrigeration system was shut down years earlier, but the ammonia charge was never removed. Workers began dismantling the system without a licensed refrigeration mechanic present. When a valve holding back pressurized ammonia was opened, a large release killed one worker, injured others, and forced nearby businesses to evacuate.

References Global News ↗ OHS Canada ↗ Cooling Post ↗

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Safety Notes for HVAC

Only qualified refrigeration mechanics should open systems containing refrigerant — even dismantling is classified as hazardous work
Require written procedures and verified documentation that the system is fully pumped down before opening
Apply OHSA duties: competent person, information/instruction, and "every precaution reasonable" for hazardous substances

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Explore These Points

What specific steps would you require before cutting into or opening any refrigerant piping?
How would you prove — to yourself — that a system is empty and isolated, not just take someone's word?

Incident 02

Carbon Monoxide Death — House Under Construction

🏗️ Construction / Temporary Heat 📍 Winnipeg, MB 💀 Fatal

A worker was found unresponsive in a house under construction where CO levels were measured above 2,000 ppm. He died at the scene; others were sent to hospital. Investigators believe a gasoline-powered pump running inside the house was the CO source. A stop-work order was issued on the gas-powered equipment.

References CTV News ↗ CBC News ↗

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Safety Notes for HVAC

CO hazards in partially enclosed work areas: temporary heaters, gas-powered pumps, unvented appliances, generators
Enforce ventilation, combustion air requirements, and prohibition of internal combustion engines indoors without proper exhaust
Connects to furnace/boiler content: incomplete combustion, venting, spillage, and employer's duty to control atmospheric hazards

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Explore These Points

What controls should be in place if a contractor insists on using a gas-powered pump or heater inside a building?
What should an apprentice do if they feel headache or nausea and suspect CO but there are no detectors?

Incident 03

Boiler Room CO Death — Building Operator Exposed

🏢 HVAC / Mechanical Room 📍 Alberta 💀 Fatal

An Alberta fatality report describes a security officer who died after exposure to high concentrations of CO from gas-fired boilers located below a building operator's room. An unsealed opening between the boiler room and the occupied area allowed combustion gases to migrate into the space.

Reference Alberta Fatality Report (PDF) ↗

🛡️

Safety Notes for HVAC

Seal all service penetrations; maintain proper combustion air and venting
Control pressure relationships between mechanical rooms and occupied spaces
OHSA duty: ensure emissions cannot enter work areas through the building envelope

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Explore These Points

During a maintenance visit, what building features — doors, seals, openings, vents — would you check around boiler rooms?
How would you document and escalate a compromised separation between a boiler room and an occupied space?

1.3.3 — WHMIS 2015 and the Globally Harmonized System (GHS)

WHMIS 2015 is aligned with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), providing consistent hazard communication worldwide. Three major hazard groups organize all regulated products.

⚡ Physical Hazards

Flammable gases, liquids, and solids
Explosives
Oxidizing materials
Gases under pressure

🏥 Health Hazards

Acute toxicity
Skin or eye irritation
Sensitization
Carcinogenicity
Reproductive toxicity

🌿 Environmental Hazards

Hazardous to aquatic environment

Label Requirements

Under WHMIS 2015, all hazardous products must carry labels that include the following six elements:

01 Product Identifier

Name of the product

02 Signal Word

"Danger" (severe) or "Warning" (less severe)

03 Hazard Pictograms

Standardized symbols indicating hazard types

04 Hazard Statements

Phrases describing the hazard (e.g., "Extremely flammable gas")

05 Precautionary Statements

Measures to minimize exposure (e.g., "Keep away from heat/sparks/open flames")

06 Supplier Identifier

Name, address, and telephone of the supplier

WHMIS Pictograms

Pictograms provide immediate visual recognition of hazards. Common ones you will encounter:

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Flame

Flammable materials

🫙

Gas Cylinder

Gases under pressure

❗

Exclamation Mark

Acute toxicity, skin/eye irritation, sensitization

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Health Hazard

Carcinogens, respiratory sensitizers, reproductive toxicity

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Corrosion

Materials that corrode metal or cause skin burns and eye damage

☠️

Skull and Crossbones

Acute toxicity (severe)

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Environment

Hazardous to aquatic environment

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Exploding Bomb

Explosives, self-reactive substances, organic peroxides

Safety Data Sheets (SDS) — 16-Section Format

Every hazardous product must have an SDS. You must know where to find SDS in your workplace and how to read them. SDS must always be readily accessible to workers.

1IdentificationProduct name, use, supplier info

2Hazard IdentificationClassification, label elements

3Composition / IngredientsChemical identity, concentration

4First-Aid MeasuresWhat to do in case of exposure

5Fire-Fighting MeasuresExtinguishing methods, special hazards

6Accidental Release MeasuresSpill cleanup procedures

7Handling and StorageSafe practices, storage conditions

8Exposure Controls / PPEExposure limits, PPE requirements

9Physical & Chemical PropertiesAppearance, odor, pH, flash point

10Stability & ReactivityConditions to avoid, incompatible materials

11Toxicological InformationRoutes of exposure, health effects

12Ecological InformationEnvironmental impact

13Disposal ConsiderationsProper disposal methods

14Transport InformationTDG classification and shipping info

15Regulatory InformationApplicable regulations

16Other InformationDate of preparation, revision history

1.3.4 — Labeling

WHMIS 2015 distinguishes between two types of labels, each with different requirements.

📦 Supplier Labels

Applied to products received from suppliers
Must include all six required label elements
Do not use products with missing or damaged labels
Labels must comply with WHMIS 2015 requirements

🏷️ Workplace Labels

Required when transferring products to other containers
Must include: product identifier (matching SDS), safe handling information, reference to the SDS
Not required for portable containers used immediately by the worker who filled them

⚠️

Key Rule

Never use a hazardous product that has a missing, unreadable, or damaged label. The label is your first line of defence — if the hazard information is gone, so is your protection.

1.3.5 — Handling Hazardous Materials

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General Handling Procedures

Read the label and SDS before using any hazardous product
Use appropriate PPE as specified on the SDS
Ensure adequate ventilation when working with volatile or toxic materials
Avoid contact with skin, eyes, and clothing
Do not eat, drink, or smoke when handling hazardous materials
Wash hands thoroughly after handling
Clean up spills immediately according to SDS procedures

❄️

Handling Refrigerants

⭐ Critical

Verify the refrigerant type before connecting any equipment
Use recovery equipment to prevent refrigerant release to atmosphere
Ensure cylinders are upright and secured when charging or recovering
Never mix refrigerants in a cylinder or system
Use proper fittings to prevent cross-contamination
Be aware of flammability when working with hydrocarbons or A2L refrigerants
Monitor for leaks using appropriate detection equipment

1.3.6 — Storing Hazardous Materials

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General Storage Requirements

Store in containers designed for the specific material
Keep containers tightly sealed when not in use
Store in designated areas, separated from incompatible materials
Provide adequate ventilation to prevent vapour accumulation
Control temperature — prevent excessive heat or cold
Protect from physical damage; store away from traffic areas
Secure cylinders — chain or strap to prevent tipping
Post appropriate signage identifying storage areas and hazards

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Refrigerant Storage

⭐ Key Rules

Temperature: Do not expose cylinders above manufacturer ratings (typically 52°C / 125°F)
Segregation: Keep flammable refrigerants away from ignition sources
Labeling: Clearly identify refrigerant type on all storage cylinders
Inventory: Track refrigerant quantities for compliance and management
Security: Prevent unauthorized access to refrigerant storage areas

Incompatible Materials — Keep Separated

⚡

Oxidizers (oxygen cylinders) away from flammable materials

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Acids separated from bases (alkaline cleaners)

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Flammable materials away from all heat sources and ignition

1.3.7 — Transporting Hazardous Materials

The Transportation of Dangerous Goods (TDG) Act governs the transport of hazardous materials in Canada. When transporting refrigerants or other dangerous goods, full TDG compliance is mandatory.

TDG Classification — 9 Classes

1Explosives

2Gases
(refrigerants)

3Flammable Liquids

4Flammable Solids

5Oxidizing Substances

6Toxic & Infectious Substances

7Radioactive Materials

8Corrosives

9Miscellaneous Dangerous Goods

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Required Documentation

Shipping document: Material details, quantity, classification
Emergency response information: Procedures for spills or accidents
TDG training certificate: Proof of training for the driver

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Vehicle & Packaging Requirements

Display appropriate placards when required
Use approved containers in good condition
Secure containers to prevent movement during transport
Do not exceed container capacity limits
Carry emergency response equipment
Ensure proper ventilation for gas cylinders
Separate incompatible materials

ℹ️

Small Quantities Exemption

Limited quantities of certain dangerous goods may be exempt from some TDG requirements. However, basic safety precautions still apply. Consult the TDG regulations or a supervisor to confirm whether an exemption applies to your situation.

1.3.8 — Disposing of Hazardous Materials

Disposal is governed by environmental regulations. Improper disposal can result in fines, environmental damage, and harm to waste handlers.

♻️

Refrigerant Recovery & Disposal

⭐ Never Vent!

Refrigerants must never be vented to the atmosphere. Violations carry significant fines and are an offence under Canadian environmental law.

Recovery: Use certified recovery equipment to remove refrigerant from systems
Cylinder management: Store recovered refrigerant in appropriate containers
Contaminated refrigerant: Must be sent for reclamation or destruction — cannot be reused or re-sold
Certification: Only certified technicians may recover refrigerants
Record-keeping: Document all refrigerant recovery and disposal activities

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Oil Disposal

Handle refrigerant oils as hazardous waste
Store used oil in designated containers
Do not mix with other waste streams
Arrange collection by a licensed waste disposal contractor

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Other Hazardous Waste & Documentation

Filters & contaminated materials: May require disposal as hazardous waste
Chemical waste: Follow SDS disposal recommendations precisely
Contaminated equipment: Decontaminate or dispose of properly
Waste manifests: Track waste from generation to final disposal
Certificates: Obtain destruction or recycling certificates
Records: Maintain quantities and types of all waste generated