If you suspect a leak, exercise caution. Natural gas is colorless and odorless, so a chemical odorant called mercaptan is added, which has a distinctive, “rotten egg” type odor.
Be aware that “odorant fade,” while uncommon, can occur. Odorant fade occurs when a physical or chemical process causes the level of odorant in the gas to be reduced. This can happen in both existing gas pipe and new installations. Be aware that some individuals may not be able to detect the smell of the natural gas odorant because they have a diminished sense of smell, because the scent is being masked by other odors in the area or because the odorant has diminished so that it is not detectable. Some gas lines, due to their unique function, may not have odor at all.