Occupational Health, Safety and Environmental Practices
Hazard groups in plumbing
Physical (cuts, falling tools, sharp sheet metal, noise from core drilling), electrical (wet hands, portable tools, immersion heaters), chemical (solvent cement and primer vapour, flux, drain acids, lead), biological (sewage, drain rods, rodents), ergonomic (lifting cylinders and CI pipes, kneeling), and work-environment (trenches, manholes, ladders, scaffolds).
Controls in order of preference
Eliminate (prefabricate off-site), substitute (water-based cleaner, lead-free solder), engineer (local exhaust, guarding, shoring, guard rails), administrate (permit to work, toolbox talk, rotation) - and PPE last.
PPE for a typical installation: helmet, goggles or face shield when cutting and threading, cut-resistant gloves (not near rotating machinery), steel-toe safety shoes, ear plugs for drilling, dust mask when chasing, harness above 2 m.
Specific rules
- Manhole and confined space: never enter without gas testing, a permit, a harness and a standby person outside. Sewer gas (hydrogen sulphide, methane) kills; a candle test is prohibited.
- Trenches: shore or slope beyond 1.2 m depth, keep spoil and tools at least 1 m from the edge, provide a ladder at 1 in 4 angle.
- Electrical: use an ELCB/RCD-protected supply; isolate water heaters before work rather than working live.
- Fire: hot-work permit for soldering; extinguisher within reach; CO2 or dry powder for electrical fires, never water.
Environment
Segregate waste - PVC offcuts, metal, packaging. Never burn PVC or cable insulation. Discharge flushing water to the sewer, not the storm drain. Use a settling pit for silt and report spills.
Worked example. A manhole 2.5 m deep is blocked. Reason it through: it is a confined space, so gas test first, then permit, standby person, harness and tripod, and rod or jet from outside. Entry only if unavoidable, with breathing apparatus. PPE alone is not a control.
Traps that cost marks
Treating PPE as the only control; testing a manhole with a match; leaving a trench open overnight without barriers and warning lights.