odorized

Odorized is a term used to describe a substance into which an odorant has been deliberately added, primarily to enable detection of leaks or contamination. The practice is most common with natural gas and liquefied petroleum gas, which are largely odorless in their pure form. Odorants are typically sulfur-containing compounds known as mercaptans or related thioethers; common examples include tert-butyl mercaptan and ethyl mercaptan. These compounds are chosen for their strong, distinctive smell and relatively low odor detection thresholds.

In industry, odorization is regulated to ensure leaks are detectable by humans while avoiding excessive odorant exposure. Standards specify acceptable odorant types and concentrations, and operators monitor and adjust levels at gas processing facilities, distribution networks, and service lines. Odorization may be performed continuously as part of gas processing or at the point of distribution, with periodic verification to maintain appropriate detectability.

Over time odorants can be diminished by adsorption, oxidation, or dilution, requiring ongoing monitoring and maintenance. Some individuals have reduced sensitivity to specific odorants, which can affect leak detection. In addition to odorized fuels, leak-detection systems and regular odorant monitoring are used to enhance safety. The term odorized thus broadly refers to the intentional addition of an identifiable smell to an otherwise odorless substance to improve safety and alertness.