Occupational Safety and Health (OSH) and Rigging

Occupational Health and Safety (OHS) and Rigging

Introduction to the Legislative and Regulatory Framework

Practicing the construction electrician trade in Canada is governed by a set of laws, regulations, and standards designed to protect workers. For the Red Seal exam, you must master the fundamental principles of the Occupational Health and Safety Act (OHSA), the Canadian Electrical Code, Part I (CE Code, Chapter V), and applicable CSA standards.

The Canadian Electrical Code, Part I (C22.1-21) is the primary reference standard for electrical installations. However, in terms of safety, it coexists with provincial occupational health and safety codes which, although varying from one province to another, share common principles: the right to refuse dangerous work, the employer's duty to provide a safe environment, and the worker's obligation to wear appropriate personal protective equipment (PPE).

The Workplace Hazardous Materials Information System (WHMIS 2015) , aligned with the Globally Harmonized System (GHS), is a federal requirement. You must know the hazard classes (physical, health, environmental) and the label elements: pictograms, hazard statements, precautionary statements, product identifier, and supplier identifier.

The Three Fundamental Worker Rights

> Exam Trap: The right to refuse does not apply if the hazard is inherent to the normal function of the job (e.g., working on an energized circuit is a normal hazard for an electrician, unless specific conditions create an abnormal danger).

Personal Protective Equipment (PPE)

PPE is the last line of defense after elimination, substitution, and engineering controls. For the electrician, PPE must be selected based on a hazard analysis specific to the task.

Head Protection

The safety helmet must comply with CSA Z94.1. Class E (electrical) helmets provide protection up to 20,000 V and are mandatory for electrical work. Classes G (general) and C (conductive) are not suitable for live work. Check for cracks, the expiry date (generally 5 years after manufacture), and replace any helmet that has sustained an impact.

Eye and Face Protection

Safety glasses compliant with CSA Z94.3 must be worn at all times. For arc flash work, the face shield must have an arc thermal performance value (ATPV) expressed in cal/cm². The table below summarizes typical incident energy levels:

> Golden Rule: Incident energy is calculated according to IEEE 1584 or the NFPA 70E method. For the exam, remember that the arc flash label on the equipment indicates the category and incident energy in cal/cm².

Hand Protection

Insulating gloves must comply with ASTM D120 or CSA Z259.12 and are classified by voltage class:

Gloves must be air-inflated and checked before each use and electrically re-certified every 6 months (classes 00 and 0) or 3 months (classes 1 to 4). Always wear leather protector gloves over insulating gloves for mechanical protection.

Foot Protection

Safety boots must comply with CSA Z195 with an insulating sole and a protective toe cap. For electrical work, the sole must be non-conductive rubber or leather (no exposed steel shank).

Lockout and De-energization Procedures

Lockout/tagout is governed by CSA Z460 "Lockout and Other Methods of Controlling Hazardous Energy." It is a mandatory procedure before any work on electrical equipment.

The Six Steps of Lockout

> Exam Trap: The verification of absence of voltage (VAT) must be performed with a voltage tester whose proper operation has been verified on a known source before and after the test. This is the "test-test-test" rule: test the tester on a known source, test for the absence of voltage, retest the tester.

Exceptions to Lockout

Live work is permitted only if:

Rule 2-304 of the Canadian Electrical Code requires that exposed live parts be protected against accidental contact by barriers, enclosures, or minimum distances.

Specific Electrical Hazards

Arc Flash

Arc flash is an electrical discharge through the air that produces a temperature of 19,000 °C to 20,000 °C (four times the surface temperature of the sun). The associated hazards are:

The arc flash boundary is the distance at which the incident energy is 1.2 cal/cm² (threshold for second-degree burns). Anyone entering this zone must wear the appropriate category of PPE.

Electric Shock

The human body is a conductor. The current flowing through the body depends on the voltage and the resistance of the body (Ohm's Law: I = V/R). Skin resistance varies from 1,000 Ω (wet skin) to 100,000 Ω (dry skin).

> Safety Rule: A current of 30 mA is considered the maximum safety threshold for a ground fault circuit interrupter (GFCI). This is why receptacles on construction sites must be protected by 5 mA GFCIs (Rule 8-200 of the Canadian Electrical Code).

The 3-Metre Rule (Proximity Rule)

For work near overhead power lines, the minimum distance is 3 m for voltages up to 75 kV. Above 75 kV, the distance increases by 10 mm per kV additional. This distance applies to persons, tools, and equipment.

WHMIS 2015 and Hazardous Materials Management

WHMIS 2015 (GHS) classifies hazardous products into two main categories: physical hazards and health hazards. Pictograms are symbols within a red-bordered diamond.

The 10 WHMIS Pictograms

The Safety Data Sheet (SDS)

The SDS contains 16 mandatory sections. The most important sections for the electrician are:

> Exam Trap: The SDS must be available in the workplace and accessible to all workers. It does not need to be on paper; electronic access is acceptable if the system is reliable.

Rigging and Lifting

Rigging is an essential skill for the electrician who must lift transformers, electrical panels, conduits, and other heavy equipment. The reference standards are CSA Z150 "Safety Code on Mobile Cranes" and CSA Z248 for tower cranes.

Types of Slings

Load Capacity and Safety Factor

The rated capacity of a sling is indicated on the label. The standard safety factor is 5:1 for wire rope slings and 5:1 for synthetic web slings (the breaking strength is 5 times the rated load).

Sling Angle

The angle between sling legs directly affects the tension in each leg. The formula is:

Tension per leg = (Load weight × Angle factor) / Number of legs

The angle factor (or tension factor) is:

> Calculation Example: A 500 kg load is lifted with a 2-leg sling forming an included angle of 60°. The tension in each leg is: 500 kg × 1.15 / 2 = 287.5 kg. The sling must have a rated capacity of at least 287.5 kg per leg.

The 60° Rule

The ideal included angle between legs is 60° to 90°. An angle greater than 120° is dangerous because tension increases rapidly. An angle of 180° is strictly prohibited because tension becomes infinite.

Sling Inspection

Before each use, inspect:

> Exam Trap: A wire rope sling must be removed from service if it has 6 broken wires over one rope lay length (or 3 broken wires in one strand). For synthetic web slings, any cut greater than 10% of the width is grounds for rejection.

Safe Lifting Procedures

Standardized Hand Signals

Crane hand signals are standardized by CSA Z150. The most common:

Working at Heights and Fall Protection

Falls are the leading cause of death on construction sites. For the electrician, working at heights is common (installing luminaires, overhead wiring, working on poles).

Fall Protection Systems

The safety harness must comply with CSA Z259.10. The lanyard with energy absorber must limit the impact force to 6 kN (600 kg) maximum. The anchor point must support a static load of 22 kN (2,200 kg).

Free Fall Distance

The maximum free fall is 1.8 m (6 feet) with an energy absorber. The total fall distance is calculated:

Total distance = Lanyard length + Absorber deployment + Worker height + Safety factor (0.6 m)

> Example: Lanyard of 1.8 m + absorber of 1.2 m + worker height of 1.8 m + 0.6 m = 5.4 m. The anchor point must be at least 5.4 m above the lower level.

Ladders and Step Ladders

Fire Safety and Extinguishers

The electrician often works near flammable materials and ignition sources. Knowledge of fire classes and extinguishers is essential.

Fire Classes

> Golden Rule: Never use water on a Class C (electrical) fire – risk of electrocution. Use a CO₂ or ABC extinguisher.

The PASS Method

To use an extinguisher: P – Pull the pin, A – Aim at the base of the fire, S – Squeeze the handle, S – Sweep from side to side.

First Aid and Emergency Response

The electrician must know basic first aid procedures, particularly for electrocution victims.

Procedure in Case of Electrocution

> Exam Trap: An electrocution victim may present entry and exit burns (often small in appearance but deep). Always treat as a medical emergency, even if the victim appears conscious.

Summary

Pitfalls to Avoid