Natural gas is generally safe and reliable, but it can be hazardous if it leaks. And because it's colorless and odorless, how do you know if it is leaking? How do you know if you need to take action to protect yourself? A malodorant — a stinky chemical called mercaptan — is added to the natural gas supply system.
The magic of mercaptan
For safety and easy detection, mercaptan is added during processing to give natural gas a distinctive odor. Most people say the sulfurous smell reminds them of rotten eggs, cooked cabbage or garlic. Mercaptan is considered non-toxic in the extremely low concentrations found in natural gas delivered to buildings.
What to do if you smell gas
Follow these steps to stay safe:
- Evacuate the area immediately.
- Stay a safe distance from the area and call 911, the local fire department or your gas company's emergency number.
- Don't smoke or light a match, candle or other flame.
- Don't turn electrical appliances or lights on or off, operate motorized equipment or vehicles or use a phone, flashlight or any device that could cause a spark.
- Leave doors and windows open.
Other signs of a gas leak
If you don't smell an odor, you may see or hear something wrong, including:
- A damaged connection to a natural gas appliance.
- Dirt, water or debris being blown into the air.
- A dry patch of grass in your yard (in an otherwise moist area).
- Exposed pipeline after an earthquake, fire, flood or other disaster.
- Dead or dying houseplants.
- Hissing, whistling or roaring near a natural gas line or appliance.
In addition to the danger of explosion, natural gas leaks in buildings can rob the air of oxygen. Physical symptoms include dizziness, headaches, flu-like symptoms, chest pains, nausea, ringing in the ears and mood changes. If you notice these problems, evacuate, go to a safe area and call 911.