Work Health and Safety and Environmental Compliance
Core concepts
Every task begins with hazard identification and risk control under the hierarchy of controls: eliminate, substitute, isolate, engineer, administrate, then PPE as the last line. Know your duty of care, incident notification triggers, and the meaning of a safe work method statement for high-risk work such as hot work, work at height and confined spaces. Refrigerant handling is a compliance activity: recovery, no deliberate venting, cylinder colour and marking rules, safe storage limits, and pressure-vessel and hazardous-area requirements. Understand oxygen-deficiency and asphyxiation risk in plant rooms, flammability classes for A2L and A3 refrigerants, ignition-source control, and refrigerant detection and ventilation. Electrical safety, isolation and lock-out/tag-out, and testing before re-energising are examinable. Environmental duties include ozone-depleting substance and synthetic greenhouse gas record keeping, leak detection and repair obligations, and lawful disposal.
Traps
Questions often reward the highest-order control rather than the easiest one, and confuse PPE with a control that removes the hazard. Watch for wording that mixes 'hazard' with 'risk'. Do not assume a plant room is safe because it is ventilated; confirm adequacy for the refrigerant charge and class. Remember that recovery cylinders must not be overfilled and that different refrigerants must not be mixed.
Worked example
A technician must braze in an occupied retail space. Elimination is impractical, so controls stack: isolate the area, use a hot-work permit and fire watch, ventilate, purge nitrogen, remove combustibles, then PPE. Never rely on PPE alone.
Rule of thumb
If you cannot state the hazard, the control and who verifies it, the job is not ready to start.