Natural gas is colorless, tasteless and odorless, making it difficult to detect. That’s why NIPSCO puts the safety additive mercaptan in natural gas, giving it a rotten-egg odor and making it easier to detect.

Mercaptan can be a useful indicator of a natural gas leak. However, you may not be able to smell this odorant if you’ve been exposed to it for long periods of time or if other odors mask the smell. Mercaptan also may be stripped from the gas due to chemical and physical processes, in an effect known as odor fade.

ALL of NIPSCO’s transmission pipelines have odorized gas, but it is important to note, not all gas is odorized.

So never rely on your nose alone to detect a natural gas leak. Instead, use your combustible gas indicator (CGI) to be certain a flammable atmosphere does not exist. And be alert for other visual and auditory gas leak warning signs, including:

• The distinctive odor of natural gas
• A hissing, whistling or roaring sound
• Dead or dying vegetation (in an otherwise moist area) over or near a pipeline
• Continuous bubbling in water
• Dirt or water being thrown into the air
• An exposed pipeline after a fire, flood or other disaster
• A damaged connection to a gas appliance