Natural gas itself has no odor. The "rotten egg" or sulfur smell you notice is a harmless additive called mercaptan that gas utilities mix in on purpose — it's an early-warning system so you can detect a leak before it becomes dangerous. That smell exists for one reason, so take any gas odor seriously. Even a faint whiff means gas is escaping somewhere it shouldn't be, and a leak can build to a hazardous level faster than most people expect. The steps below are the same ones I give every customer.
The 5 things to do right now
- Don't create a spark. Don't flip light switches, unplug anything, or use anything with a flame or pilot — even a tiny spark can ignite gas in the air.
- Don't use your phone indoors. Leave it; phones and electronics can spark. Call once you're outside and clear of the building.
- Get everyone out. Leave the building immediately and move to fresh air, leaving the door open behind you if it's easy and safe to do so.
- Call your gas utility's emergency line (and 911 if anyone feels unwell) from outside or a neighbor's home, not from inside.
- Then call a licensed gas fitter to find and repair the source before gas is turned back on.
Don't go back in until it's cleared
Once you're out, stay out. Don't return to grab belongings, check the stove, or "just see if it's still there." Wait for the gas utility or a qualified professional to inspect the home, shut off the supply if needed, ventilate it, and tell you in person that it is safe to go back inside. A leak you can no longer smell is not the same as a leak that's been fixed.
Preventing gas problems
Most gas emergencies trace back to work that was never done properly. A few habits keep your home safe:
- Use a professional. Have gas appliances and lines installed and serviced by a licensed gas fitter — never improvise a fitting or connector.
- Don't DIY gas work. A loose joint or wrong material can leak for months. Leave all gas work to a licensed pro.
- Watch for symptoms. A hissing sound near a line, dead or dying vegetation along an underground pipe, or a pilot light that won't stay lit can all signal a problem.
- Consider a gas detector. A natural-gas detector adds a layer of protection, especially near appliances and in lower levels where gas can collect.
If you smell gas, safety first — get everyone out and call from outside. Don't try to find the leak yourself. Once it's safe, we're available 24/7 emergency across Greater Boston.
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