Health, Safety, and Environmental Controls
What the exam tests
Health, safety, and environmental controls tests risk assessment, the hierarchy of controls, permit-to-work systems, and environmental protection. Questions ask you to rank controls correctly and to identify residual risk.
Core rules and concepts
- Hierarchy of controls: eliminate, substitute, engineering controls, administrative controls, then PPE. PPE is the last line of defence, not the first.
- Risk = likelihood × severity; a 5 × 5 matrix scores before and after controls, and residual risk must be recorded and reviewed.
- Excavations need support or battering, edge protection, access, and gas or service checks; spoil heaps stay back from the edge.
- Work at height requires guardrails, toe boards, and a rescue plan; ladders are for access, not as a work platform.
- Environmental controls include silt traps, wheel washes, dust suppression, spill kits, and segregated waste; noise and vibration limits are monitored at the receptor.
Worked example
A task is scored 4 (likely) × 5 (major injury) = 20, high risk. Installing a guardrail and a rescue plan reduces likelihood to 2 and severity to 3, giving 2 × 3 = 6, medium risk. The reasoning shows that controls change both terms, but the residual score remains above zero, so the activity still needs supervision and periodic review.
Traps that cost marks
- Listing PPE as the primary control.
- Recording a residual risk of zero after controls.
- Ignoring environmental aspects such as silt discharge or spill pathways.
- Failing to review the assessment when the method or site condition changes.
- Treating a permit to work as a substitute for physical isolation.