Trade Safety, Rigging, and Workplace Practices

Trade Safety, Rigging, and Work Practices

Introduction to the Chapter

This first chapter covers the fundamentals of safety, rigging, and work practices essential to the gasfitter — Class A trade. The Interprovincial (Red Seal) exam evaluates not only your technical knowledge of installing and repairing gas appliances, but also your ability to apply safety rules, handle loads correctly, and use personal protective equipment (PPE) in accordance with national standards. This chapter prepares you to answer questions on legal obligations, hazards specific to natural gas and propane, safe rigging procedures, and nationally recognized work practices.

1. Regulatory Framework and Applicable Standards

1.1 National Reference Standards

As a Class A gasfitter, you must know and apply the following standards, which are applicable nationally across Canada:

Standard	Title	Primary Application
CSA B149.1	Natural Gas and Propane Installation Code	Installation, modification, repair of appliances and piping
CSA B149.2	Propane Storage and Handling Code	Temporary propane on construction sites
CSA B149.3	Code for the Field Approval of Fuel-Related Components	Performance and safety requirements for appliances
CSA Z462	Workplace Electrical Safety	Protection against electrical hazards (arc flash)
CSA Z432	Safeguarding of Machinery	Guards and protective devices
Hazardous Products Act	WHMIS (Workplace Hazardous Materials Information System)	Classification, labelling, safety data sheets (SDS)
Canadian Electrical Code, Part I	Electrical installation of appliances	Electrical connection of gas appliances (Rule 8-200 for branch circuits)

Exam Focus: CSA B149.1 is the primary reference for all gasfitter work. Exam questions frequently cover clearance distances, ventilation requirements, and decommissioning procedures.

1.2 Legal Obligations of the Gasfitter

The Class A gasfitter is a licensed tradesperson who must:

Hold a valid certification from their province or territory (recognized by the Red Seal).

Work according to the codes and standards in effect at the time of installation.

Obtain the required work permits from the authority having jurisdiction (gas inspector).

Perform tightness testing and commissioning in accordance with code procedures.

Complete and sign installation reports and certificates of compliance.

Duty of Care: You must refuse to perform work if conditions present an imminent danger to the safety of persons or property. This obligation takes precedence over any directive from the employer or client.

2. Hazards Specific to Natural Gas and Propane

2.1 Physical Characteristics and Hazards

Property	Natural Gas (Methane)	Propane
Relative density (air = 1)	0.60 (lighter than air)	1.52 (heavier than air)
Lower explosive limit (LEL)	4%	2.1%
Upper explosive limit (UEL)	15%	9.5%
Auto-ignition temperature	~537 °C	~493 °C
Odour	Added (mercaptan)	Added (ethanethiol)

Practical Consequences:

Natural gas accumulates at the ceiling. Gas detectors must be installed high up.

Propane accumulates at floor level. Detectors must be installed near the floor. Any propane leak in a basement or cellar presents an extremely high explosion risk.

The LEL is the minimum concentration of gas in air required for ignition. Below this value, the mixture is too lean to burn.

2.2 Asphyxiation and Carbon Monoxide (CO) Poisoning Hazards

Carbon monoxide is a colourless, odourless, toxic gas produced by the incomplete combustion of hydrocarbons. Symptoms of exposure include headaches, nausea, confusion, and loss of consciousness. CO binds to hemoglobin with an affinity approximately 250 times greater than that of oxygen.

Safety Rules:

Any work on a gas appliance must include a ventilation check and chimney draft verification.

If CO presence is suspected, use a calibrated portable detector before entering the area.

Gas appliances must be installed with a combustion air supply in accordance with CSA B149.1 (Section 8).

2.3 Electrical Hazards

The gasfitter often works near electrical circuits (thermostats, valves, fans). CSA Z462 defines approach limits and PPE requirements for work near hazardous voltages.

Practical Rule: Before any work on an appliance, disconnect the electrical supply at the distribution panel and lock out/tag out. Never rely on a wall switch alone.

3. Personal Protective Equipment (PPE)

3.1 Mandatory Basic PPE

PPE	Use	Reference Standard
Safety helmet	Protection against impacts and falling objects	CSA Z94.1
Safety glasses	Eye protection against projectiles	CSA Z94.3
Safety footwear	Foot protection against impacts and punctures	CSA Z195
Work gloves	Hand protection against cuts and abrasions	CSA Z195.1
Hearing protection	Noise reduction (construction sites, compressors)	CSA Z94.2

3.2 Gas-Specific PPE

Portable gas detector (oxygen, LEL, CO, H₂S): must be calibrated and tested before each use. Oxygen reading must be between 19.5% and 23.5% for safe entry.

Respiratory protection: in the event of a gas leak or insufficient ventilation, use a self-contained breathing apparatus (SCBA) — never a cartridge filter mask for natural gas or propane, as these gases displace oxygen.

Antistatic clothing: in classified areas (gas present), avoid synthetic fibre clothing that generates electrostatic discharges.

Exam Focus: A classified location is defined in CSA B149.1 as an area where an explosive atmosphere may be present. Electrical equipment in these areas must be certified for use in explosive atmospheres (Class I, Division 1 or 2).

4. WHMIS and Hazardous Materials Management

4.1 WHMIS Classification

The Workplace Hazardous Materials Information System (WHMIS) classifies products into categories:

Flammable gases (Category 1): propane, butane, acetylene.

Gases under pressure: compressed gas cylinders.

Flammable liquids: solvents, degreasers.

Corrosives: acids for pipe cleaning.

4.2 Safety Data Sheets (SDS)

Every hazardous product must have an SDS accessible in the workplace. The SDS contains:

Product and supplier identification.

Composition and ingredients.

First aid measures.

Firefighting measures.

Accidental release measures.

Handling and storage.

Exposure controls and personal protection.

Exam Rule: Before using any chemical product (e.g., leak detection solution, pipe detergent), you must consult the SDS and wear the required PPE.

5. Lockout/Tagout Procedures

5.1 Lockout/Tagout Principles

Lockout/tagout is a mandatory procedure to prevent accidental start-up of equipment during maintenance or repair work. The steps are:

61.Identify all energy sources (gas, electrical, hydraulic, pneumatic, thermal).

62.Notify affected personnel of the planned shutdown.

63.Shut down the equipment using normal procedures.

64.Isolate energy sources (close valves, disconnect circuits).

65.Lock isolation devices with a personal lock.

66.Tag with name, date, and reason.

67.Verify the absence of residual energy (purge the gas line, test with a manometer).

68.Test the equipment to confirm it will not start.

Gas Specifics: For a gas pipeline, lockout involves closing the main shut-off valve, purging the piping section (with discharge to the outside), and verifying the absence of pressure with a manometer or soap-and-water test.

5.2 Multiple Lockout

When several workers are working on the same equipment, each worker must place their own lock on a multiple lockout device (hasp). A lock may only be removed by the person who installed it, except in an emergency with a removal procedure authorized by the supervisor.

6. Rigging and Manual Material Handling

6.1 Safe Lifting Principles

The gasfitter frequently handles heavy loads: water heaters (50 to 150 kg), boilers, compressors, cast iron or steel piping. The basic principles are:

Assess the load before lifting it (weight, size, grip points).

Bend your knees, keep your back straight, load close to the body.

Do not twist your torso while lifting.

Ask for help if the load exceeds 25 kg or is awkward to handle.

Use mechanical lifting equipment (pallet jack, hand truck, hoist) whenever possible.

Recommended Lifting Limit: For a healthy adult worker, the recommended maximum load is 25 kg for occasional lifting and 15 kg for repetitive lifting. Beyond that, use mechanical equipment.

6.2 Slings and Lifting Accessories

Sling Type	Advantages	Limitations	Inspection
Chain sling (Grade 80/100)	High strength, resists abrasion and heat	Heavy, may damage surfaces	Check links, hooks, wear (10% diameter reduction = removal)
Wire rope sling	Flexible, resists abrasion	Do not bend at sharp angles, risk of deformation	Count broken wires (6 wires over a length of 6 diameters = removal)
Polyester sling (web)	Lightweight, will not scratch surfaces	Sensitive to heat (max 90 °C), cuts	Check stitching, tears, UV exposure

Rigging Rules:

The sling angle must not exceed 90° between legs; the ideal angle is 60° from the horizontal.

The working load limit (WLL) is indicated on the sling label. Never exceed it.

Hooks must have a functioning safety latch.

Before each lift, visually inspect the sling and accessories.

6.3 Calculating Load on Slings

The tension in each leg of a sling increases as the angle decreases. The formula is:

T = (P / n) × (1 / sin θ)

Where:

T = tension in each leg (kg or N)

P = total weight of the load (kg or N)

n = number of legs

θ = angle between the leg and the horizontal (in degrees)

Example: A boiler weighs 400 kg. You use a 2-leg sling with a 45° angle from the horizontal.

T = (400 / 2) × (1 / sin 45°) = 200 × (1 / 0.707) = 200 × 1.414 = 283 kg per leg

If the angle were 30°, the tension would be: 200 × (1 / 0.5) = 400 kg per leg. The angle is therefore critical: the smaller the angle, the greater the tension.

Exam Focus: Sling tension calculation questions are common. Memorize the sin values for common angles: sin 30° = 0.5; sin 45° = 0.707; sin 60° = 0.866.

6.4 Mechanical Lifting: Hoists and Winches

Chain hoists: capacity from 0.5 to 20 tonnes. Check the load brake and lifting chain.

Lever hoists (come-alongs): for tensioning and positioning loads. Never use as a support sling.

Hydraulic jacks: high capacity, but risk of slow descent. Always block the load with cribbing after lifting.

Cranes and forklifts: reserved for certified operators. The gasfitter may be called upon to direct the load — you must then know the standard hand signals.

Standard Hand Signals (per ASME B30.2):

Signal	Meaning
Arm horizontal, thumb up	Hoist
Arm horizontal, thumb down	Lower
Arm extended, open hand, lateral movement	Move horizontally
Closed fist, arm bent	Emergency stop
Both hands on head, elbows bent	Stop all

7. Confined Spaces and Hazardous Atmospheres

7.1 Definition of a Confined Space

A confined space is a space that:

Is large enough for a person to enter and work in;

Has limited access (difficult entry and exit);

Is not designed for continuous occupancy.

Examples: tanks, pits, manholes, ducts, combustion chambers.

7.2 Confined Space Entry Procedure

115.Entry permit signed by the supervisor.

116.Atmospheric testing before entry: oxygen (19.5–23.5%), flammable gases (less than 10% of the LEL), CO (less than 35 ppm), H₂S (less than 10 ppm).

117.Continuous ventilation of the space.

118.Attendant outside, in constant communication.

119.Rescue equipment: harness, lifeline, rescue winch.

120.Lighting certified for explosive atmospheres if gas is present.

Exam Rule: In a confined space where a gas line has been cut, the purge must be performed with an inert gas (nitrogen) or by air dilution, and the gas concentration must be verified with a calibrated detector before entry.

8. Fire Safety and Emergency Response

8.1 Fire Classes and Extinguishers

Fire Class	Material	Appropriate Extinguisher
A	Solids (wood, paper, fabric)	Water, ABC powder
B	Flammable liquids (gasoline, solvents)	ABC powder, CO₂, foam
C	Electrical equipment	CO₂, ABC powder
D	Combustible metals (magnesium, sodium)	Special D powder
K	Cooking oils	Special K foam

Basic Rule: Never use water on a Class B or C fire. For a gas fire, close the shut-off valve if possible, then use an ABC powder extinguisher.

8.2 Gas Leak Response Procedure

127.Evacuate the immediate area and alert occupants.

128.Do not operate electrical switches, do not use a telephone, do not light any flame.

129.Close the main shut-off valve if accessible without danger.

130.Ventilate by opening doors and windows from the outside.

131.Call the gas emergency service and the fire department.

132.Do not restore service until the leak has been identified and repaired.

Exam Focus: The emergency shut-off valve must be installed outside the building or in an accessible location. The gasfitter must know its exact location before beginning any work.

9. Tools and Safe Work Practices

9.1 Gasfitter-Specific Tools

Chain wrench: for large-diameter piping. Never use an extension (cheater bar) on a wrench.

Pipe cutter: for cutting steel, copper, PEX. Always deburr the ends.

Electronic leak detector: calibrated before each use.

Manometer (test gauge): for tightness testing. Use a dial manometer from 0 to 35 kPa (0 to 5 psi) for low pressures.

Tracing wire: for locating buried piping.

9.2 Tool Usage Rules

Inspect tools before each use (cracks, wear, electrical insulation).

Use insulated tools (ASTM F1505 standard) for work near electrical circuits.

Never carry tools in your pockets when working at heights.

Wear safety glasses when cutting, grinding, or drilling.

Compressed gas cylinders (acetylene, oxygen) must be stored upright, secured, with protective caps in place.

10. Waste Management and Environmental Protection

10.1 Construction Site Waste

Used piping: recycle metal (steel, copper, cast iron).

Insulation: materials containing asbestos (old piping) must be handled by a certified contractor.

Chemicals: never pour solvents or detergents into drains. Use designated collection containers.

10.2 Refrigerants

Air conditioning units and heat pumps contain refrigerants (R-410A, R-32). Handling these gases is regulated by Environment Canada's Ozone-depleting Substances and Halocarbon Alternatives Regulations. The Class A gasfitter must:

Recover refrigerants before dismantling a unit.

Use a certified recovery machine.

Keep a log of recovered quantities.

Summary

The Class A gasfitter must know and apply CSA B149.1 (natural gas and propane installation), CSA B149.2 (propane on construction sites), and CSA B149.3 (gas appliances).

Natural gas is lighter than air (accumulates high); propane is heavier (accumulates low). The LEL of natural gas is 4%, and that of propane is 2.1%.

Carbon monoxide is a silent hazard: check ventilation and chimney draft on every job.

Lockout/tagout is mandatory to isolate all energy sources (gas, electrical) before any maintenance work.

Safe rigging relies on load assessment, using slings in good condition, and respecting sling angles. Tension in a leg increases as the angle decreases: T = (P/n) × (1/sin θ).

Confined spaces require a permit, atmospheric testing, ventilation, and an attendant.

In the event of a gas leak: evacuate, do not operate switches, close the valve, ventilate, call emergency services.

Extinguishers must be selected according to fire class: A (solids), B (liquids), C (electrical).

WHMIS requires consulting SDS before using any hazardous product.

Environmental protection includes refrigerant recovery and metal recycling.

Common Pitfalls to Avoid

169.Confusing the density of natural gas and propane: natural gas rises, propane sinks. An exam question may describe a leak in a basement — the correct answer is propane, not natural gas.

170.Forgetting that the LEL is a minimum limit: below 4% (natural gas), the mixture is too lean to burn; above 15%, it is too rich. Explosion is possible between these two limits.

171.Using a cartridge filter mask for gas: this is a serious error. Natural gas and propane displace oxygen; only a self-contained breathing apparatus is acceptable.

172.Neglecting the sling angle: a 30° angle doubles the tension compared to a 90° angle. Always check the angle before lifting.

173.Failing to purge the line before cutting: any piping section containing gas must be purged to the outside, never inside a building.

174.Trusting a wall switch to cut power: lockout at the panel is mandatory.

175.Ignoring signs of CO presence: headaches, nausea, confusion — these symptoms in occupants indicate incomplete combustion. Act immediately.

176.Using a damaged sling: a chain sling with a 10% diameter reduction must be removed from service. Do not attempt to repair it.

177.Forgetting to check the SDS: before using a leak detection product or detergent, consult the SDS. An exam question may cover first aid for eye contact.

178.Not knowing hand signals: if you are directing a load, you must know the standard signals. An incorrect signal can cause a serious accident.

179.Entering a confined space without atmospheric testing: even if the line has been purged, oxygen may be insufficient. Testing is mandatory before every entry.

180.Confusing fire classes: a gas fire is a Class B fire (flammable liquid/gas). Use an ABC powder extinguisher, never water.