Workplace Safety
What this domain tests
This domain checks hazard and risk recognition, the hierarchy of controls, PPE, safety signs, fire and electrical safety, machine guarding, incident reporting and basic first aid.
Core ideas
- Hazard vs risk: a hazard is anything with potential to harm; risk is the chance and severity of that harm occurring.
- Hierarchy of control: eliminate, substitute, engineering controls, administrative controls, then PPE as the last line. PPE protects only the wearer and only if it fits and is worn correctly.
- Safety sign colours: red for prohibition and fire equipment, yellow for warning, blue for mandatory action, green for safe conditions and escape.
- Fire: the fire triangle needs heat, fuel and oxygen. Never use water on live electrical fires; use CO2 or dry powder. Match the extinguisher class to the fuel.
- Electrical safety: isolate and lock out before work, test for dead, avoid wet hands, use insulated tools, do not overload sockets.
- Machines: guards must never be bypassed or removed; report missing guards before operating.
- Incidents: report injuries, near misses and damage promptly; near misses are free warnings.
Worked example
A bench grinder has its wheel guard removed and is placed beside an open solvent container. Hazards: rotating wheel and flying fragments; solvent vapour ignition. Risk is high because both severity and likelihood are high. Correct order of control: refit the guard, move the solvent to a ventilated store, create a safe distance, then issue eye protection and instruct workers. Reasoning: removing the hazard or engineering it out is stronger than relying on goggles, and PPE would not stop a burst wheel.
Mark-losing traps
- Choosing PPE first instead of last.
- Using water on an electrical fire.
- Treating a near miss as nothing to report.
- Bypassing interlocks to save time.
- Confusing the colour of a warning sign with a mandatory sign.