Plumbing & Pipefitting

Plumbers and pipefitters work in trenches, crawl spaces and mechanical rooms, with torches, threading machines and heavy pipe, and sometimes with sewage and pressurized systems.

• Construction
• General Industry

Top hazards

• Trench cave-ins on underground work. See Trenching.
• Burns and fires from soldering and brazing torches
• Pipe threaders and power vises catching clothing or gloves
• Sewer gas (H2S) and biological hazards
• Pressure and steam releases during testing or when opening lines
• Heavy pipe handling, overhead work, ladders and lifts
• Asbestos pipe insulation and lead in older buildings

Key practices

• Get a hot work permit and have an extinguisher when using torches. Use heat shields near combustibles.
• Use the foot switch on threading machines and keep gloves and sleeves away from rotating pipe.
• Isolate, drain, depressurize and lock out lines before opening them.
• Use pneumatic test pressure only when approved; prefer hydrostatic tests.
• Wash hands and wear gloves for sewer work; get vaccinations your employer recommends.
• Use pipe stands, racks and lifting aids.

Torches and hot work

• Most plumbing fires start when a torch heats wood framing, insulation or dust inside a wall. Use a heat shield, wet down nearby wood if allowed, and keep an extinguisher in reach.
• Stay and watch the area after soldering. Fires can smolder in walls and break out later. Many hot work permits require a fire watch. See Hot Work Permits.
• Secure gas cylinders upright and close valves when done. See Compressed Gas Cylinders.
• Press fittings and push-fit fittings avoid flames entirely where they’re allowed.

Opening lines safely

1. Identify what’s in the line, its pressure and temperature.
2. Isolate it with valves, and lock and tag them.
3. Drain and depressurize, and confirm with gauges or a bleed valve.
4. Open slowly, away from your face, with the right PPE.

Steam and hot water lines can cause severe burns, and trapped pressure can blow fittings off. See Lockout/Tagout.

Drain cleaning

Drain machines and sewer cables can whip, twist and break fingers and wrists. Use the foot switch, wear the gloves the manufacturer recommends (often special leather mitts), and never grab a turning cable with a regular glove. Drain chemicals can splash and burn; use eye protection.

Job checklist

• Lines isolated, locked and depressurized before opening
• Hot work permit, heat shield and extinguisher for torches
• Threader and drain machine guards and foot switches working
• Gloves, glasses and hygiene supplies for sewer work
• Asbestos and lead checked in older buildings
• Lifting aids for heavy pipe and fixtures

Last updated: October 1, 2026