Some persons may not be able to smell the odor because they have a diminished sense of smell, olfactory fatigue (normal, temporary inability to distinguish an odor after prolonged exposure to it) or because the odor is being masked or hidden by other odors that are present, such as cooking, damp, musty or chemical odors. In addition, certain conditions in pipe and soil can cause odor fade the loss of odorant so that is not detectable by smell.
Sometimes physical and/or chemical processes can cause a loss of odorant in natural gas, making it undetectable by smell. Odor fade is more likely to occur in the following situations:
- In new, steel pipe that has been recently manufactured or hasn hasn’t been used for odorized natural gas before
- In natural gas piping systems using higher gas pressure, and when natural gas flow is limited or intermittent
- In the presence of rust, mill scale, moisture, air, cutting oil, pipe thread compound, liquids, condensates and other substances
Because of the possibility of odor fade, it's important to not rely only on your sense of smell to be alerted to a natural gas leak.
For a printable copy about odor fade and safe purging practices, see our Safety Brochures and Materials . If you
have additional questions or concerns regarding pipe conditioning or odor fade, call us at 1-800-427-2200 or contact a licensed, qualified professional.