What is propane odorant (ethyl mercaptan)?

Raw propane contains no natural odor, which poses a serious safety hazard. Ethyl mercaptan, a sulfur-containing compound, is added to propane in small quantities to produce the strong, rotten-egg smell that alerts users to gas leaks. This odorant is required by federal regulation for propane distributed to end users in the United States.

The concentration of ethyl mercaptan in propane is carefully controlled. Propane suppliers in Florida and across the country must maintain precise odorant levels to ensure detection while avoiding overpowering smells that could mask the underlying hazard or create false alarms. The odorant can be detected by most people at extremely low concentrations, well below dangerous exposure levels.

Ethyl mercaptan does not affect propane's performance as a fuel. It remains stable through storage, transport, and combustion without altering combustion efficiency or equipment operation. Some specialized industrial uses of propane (such as odorless propane for certain applications) may have odorant removed before use, but consumer propane for heating, cooking, and appliances always contains the required ethyl mercaptan additive. This odorant is essential for preventing accidents and enabling quick response to leaks in homes, businesses, and fleet operations throughout Florida.