Answer: Natural gas is odorless in its natural state, but it’s artificially odorized by an organic sulfur compound called mercaptan. Gas companies add mercaptan to the natural gas to give it a distinct, identifiable odor for customer recognition. This minimizes risks to public safety and complies with federal regulatory requirements.
A distribution line must be odorized so that at a concentration in air of 1/5 of the lower explosive limit (LEL), the gas is readily detectable by a person with a normal sense of smell. This is the equivalent of 1% gas in air or 20% LEL. Each operator must conduct periodic sampling with an air dilution instrument that can determine the percentage of gas in air at which the odor becomes readily detectable.
Tip: Odorant is the customer’s leak detector. It provides the public with an effective warning device about a possible gas leak problem. When you smell gas in or around your home, call the gas company to come out and investigate. Safety must never be overlooked!