Propane characteristics Safety reminders If you smell gas Uncapped lines Safety relief valve Read your tank gauge Appliance safety Lighting pilots Maintenance Gas grilling tips Weather emergencies Download PDF version Disclaimer       General propane characteristics Propane is transported and stored as a liquid. Propane (sometimes called LPG or LP-gas) is a colorless and odorless gas. Since propane is odorless, it is intentionally odorized so leaks can be detected. The odor is similar to rotten eggs. Call the Railroad Commission’s Alternative Fuels Division at (800) 64-CLEAR for a free “scratch-and-sniff” pamphlet that can help familiarize you, your family, and your co-workers with the smell of propane. Propane vapors are heavier than air and may accumulate in low-lying areas such as basements and ditches or along floors. Propane is flammable when mixed with air (oxygen) and can be ignited by many different sources.