Propane is a nontoxic, non-carcinogenic and non-corrosive fuel that poses no harm to groundwater or soil. It is an approved alternative fuel under the Clean Air Act.
Propane buses meet the same rigorous U.S. Federal Motor Vehicle Safety Standards (FMVSS) and are equipped with several safety features that make propane buses very safe. The system is designed with automatic safety valves that are backed up by mechanical safety valves throughout to keep the fuel and the passengers safe at all times. In addition, the fuel itself is relatively low pressure; although it changes with temperature, it doesn’t exceed 312 PSI and is usually far lower.
Propane autogas vehicle fuel tanks are 20 times more puncture-resistant than gasoline or diesel tanks. They are constructed from carbon steel in compliance with the American Society of Mechanical Engineers. Propane will not ignite when combined with air unless the source of ignition reaches at least 940 degrees Fahrenheit. In contrast, gasoline will ignite when the source of ignition reaches 430 degrees.
Propane autogas engines are also noticeably quieter. This provides an unexpected safety feature of allowing drivers to better hear and communicate with students onboard.