Occupational health, safety, and environmental practices
Domain 1: Occupational health, safety, and environmental practices
This domain tests how you identify, control, and document hazards around a tower crane. Expect questions on the hierarchy of controls, fall protection, electrical limits of approach, wind, housekeeping, spill response, and the worker's right to refuse unsafe work.
Core rules
- Apply the hierarchy of controls: eliminate the hazard, then engineer it out (guardrails, barriers, de-energizing), then administrative controls (procedures, training, signage), and use PPE as the last line.
- Everyone on site has stop-work authority. A worker who believes work is unsafe can refuse; the employer must investigate and, if the worker remains unsatisfied, involve the joint health and safety committee or regulator.
- Fall protection: use guardrails where possible. When fall arrest is used, wear a full-body harness with a shock-absorbing lanyard or self-retracting device, anchor to a point rated for the load (commonly 22 kN / 5,000 lbf) and have a rescue plan. Inspect harnesses and lanyards before each use.
- Electrical: maintain the jurisdiction's limit of approach. For example, Ontario construction sets a 3 m limit for lines over 750 V up to 150 kV, 4.5 m for 150-250 kV, and 6 m above 250 kV. If work inside the limit is unavoidable, use a written procedure, de-energize or isolate, and a dedicated signaler.
- Wind: the anemometer at the jib top is the reference, not ground-level wind. Stop at the manufacturer's maximum operating wind speed and at lower limits for loads with large sail area. Secure the crane for out-of-service wind per the manual.
- Environment: contain hydraulic and fuel leaks with drip trays and spill kits; do not hose spills to storm drains; manage noise, dust, and waste; check for nesting birds before work near the jib.
Worked example
The jib anemometer reads 11 m/s and the manual allows operation to 20 m/s, so the operator starts a lift of a 12 m2 form panel. The manufacturer's load-specific table limits that panel to 10 m2 at 11 m/s. Reasoning: the 20 m/s limit is a crane limit, not a load limit; the panel can act as a sail and overload the jib or cause loss of control. The correct decision is to wait or reduce the panel area, and record the decision.
Traps that cost marks
- Using ground-level wind or "it feels calm" instead of the jib anemometer.
- Treating fall arrest as fall prevention, or ignoring anchor rating and rescue.
- Assuming PPE substitutes for engineering controls.
- Ignoring a small hydraulic leak that can cause a slip or reportable spill.
- Not barricading the swing radius or counter-jib area.