Indoor Gas Leaks: Monitor the Atmosphere

Use your combustible gas indicator (CGI) to monitor the air around the building.

If gas concentrations do not exceed 1% (or 20% of LEL) and you can enter the building without risk, check for natural gas in the following locations:

  • The areas where any underground water, sewer, electric or drain lines enter the building
  • The regulator, meter bar and all piping that supplies natural gas as well as the piping around all gas-fired appliances, such as water heaters and clothes dryers
  • The spot where the gas service enters the building
  • Any cracks in the wall
  • All high points in the ceiling where natural gas could collect