Occupational Health, Safety and Environment
The Occupational Health, Safety and Environment domain checks whether you can spot site hazards, apply the hierarchy of control, use PPE correctly, and handle waste and chemicals lawfully. At Certificate II you work under supervision, but you are still expected to stop unsafe work and report it. Questions mix hazard identification, confined-space rules and Ghanaian legal duties.
Hazards you meet on plumbing work
- Physical: cuts from sheet metal and glass, eye injuries from chipping concrete, hand-arm vibration, noise from core drills, trips in open trenches, falls from roof-tank stands and ladders.
- Chemical: solvent cement and primer (flammable, narcotic fumes), drain acids, chlorine, lead solder fume, cement dust (alkaline burns).
- Biological: sewage, rat urine in drains (leptospirosis), mould inside cisterns.
- Atmospheric: hydrogen sulphide and methane in manholes and septic tanks, oxygen deficiency.
- Fire: soldering and brazing near timber, LPG cylinders stored inside vehicles.
Hierarchy of control
Apply in order: eliminate (rod a drain from the surface through a rodding eye instead of entering), substitute, engineer (forced ventilation, guards, trench support), administer (permit to work, signage, training), then PPE as the last layer. PPE for drain work is boots, gloves, goggles, hi-vis, dust mask, and a harness with gas detector for confined spaces.
Rules that carry marks
- The Factories, Offices and Shops Act, 1970 (Act 328) requires safe premises, first aid and accident reporting; the Labour Act, 2003 (Act 651) sets the employer's duty to provide a safe system of work.
- Treat any chamber, tank or pit as a confined space: test the air (oxygen 19.5–23.5%, flammable gas below 10% LEL, hydrogen sulphide below 5 ppm), ventilate, then enter with harness, tripod, communications and a standby person.
- Store LPG upright, outdoors, away from drains and ignition sources.
- Never pour cement, solvent, acid or waste oil into a drain or watercourse; the EPA Act, 1994 (Act 490) governs waste handling.
Worked example
A blockage sits in a 2.5 m deep inspection chamber. Step 1, eliminate entry: rod from the surface through the rodding eye. Step 2, if entry is unavoidable: isolate, obtain a permit, gas-test, force-ventilate for 10 minutes, re-test, then enter with harness, tripod and a second person at the top. Reason: controls are applied in order, and the standby person never enters without breathing apparatus - most confined-space deaths in drains are would-be rescuers.
Traps
- Treating PPE as the first control rather than the last.
- "It smells of gas, so it must be unsafe" - smell is not a test; use a calibrated detector.
- Storing solvent cement in a hot van or cab.
- Not reporting near misses.