Gas Fitters & Gas Utility Workers

Gas fitters install and repair natural gas and propane piping and appliances. A small leak in the wrong place can cause an explosion, and a poorly vented appliance can poison a household with carbon monoxide. Training, testing and careful purging prevent both.

• Construction
• Utilities
• Plumbers & HVAC

Top hazards

• Explosions and fires from leaks, especially in basements and enclosed spaces
• Carbon monoxide from improperly vented or adjusted appliances
• Gas released indoors during purging
• Damaged gas mains and service lines during excavation
• Asphyxiation in vaults and trenches with gas
• Confined spaces like crawl spaces and meter pits

Key practices

• Shut off and lock out the gas supply before working, and verify it’s off.
• Pressure test new piping as code requires before putting it in service.
• Check for leaks with leak-test solution or a combustible gas detector, never a flame.
• Purge safely: purge lines to the outdoors or through a burner in a controlled way, never into a closed room. Monitor the area with a gas detector. See Gas Detectors.
• Remember odorant fade: new piping can absorb the rotten-egg odorant, so you may not smell a leak. Use a detector.
• Vent appliances correctly and check for CO and proper draft after installation or repair. See Carbon Monoxide.
• Bond CSST (corrugated stainless steel tubing) as the maker and code require to reduce lightning damage.
• Call 811 and hand dig near gas lines. See Call 811.

Licensing

Most states and cities require gas fitters to be licensed, and utilities require their own qualifications for work on mains and services (federal pipeline rules include operator qualification for covered tasks). Check local requirements before doing gas work.

Last updated: October 2, 2026