No, propane in itself is not toxic or poisonous. Like any flammable gas, it is perfectly safe if you store it and handle it correctly. When used, propane produces heat, water vapor, nitrogen and carbon dioxide. If inhaled, propane has anesthetic properties and can make people dizzy in high concentrations.
Propane is non-toxic for people
While propane in itself is not toxic for people, users should be careful about two aspects of propane usage. First, liquid propane is particularly cold. Its boiling point is -44°F. Therefore, if it comes into contact with human skin it can cause cryogenic burns or frostbite, for example. This is particularly harmful in the eye region, which is why it is recommended to use goggles when handling propane (as employees of propane companies do when they maintain your tank). The best way to avoid coming into contact with liquid propane is to ensure your tank valves are functioning properly.
As a gas, propane is heavier than air and can displace oxygen in a room. This is only an issue if there is an indoor propane leak. This is why propane tanks and cylinders are best stored outdoors. Nearly a quarter of propane-related deaths are due to carbon monoxide inhalation. Again, there is no risk of carbon monoxide intoxication if your propane-run applications are properly adjusted. This is the point of having a Gas Systems Appliance Check done by your propane company. Another complimentary and easy prevention solution is to buy carbon monoxide detectors for the rooms in which you have propane appliances. They are readily available in stores or on the Internet.
Propane is non-toxic for the environment
As a non-toxic gas, propane is not harmful to your immediate natural environment. Propane leaks pose no threat to the vegetation or soil on your property. The same goes for aquifers and groundwater supply.
Propane is also one of the cleanest burning alternative fuels. Indeed, it is listed in both the Clean Air Act (1990) and the National Energy Policy Act (1992) as an approved clean fuel and propane installations are not controlled by the Environmental Protection Agency. It is cleaner in terms of carbon dioxide release per million BTU (unit to measure performance for a source of energy) than coal, heavy fuel oil, diesel, kerosene, gasoline or ethanol. The Propane Education & Research Council’s figures show that propane is responsible for less than its share of total GHG emissions and GHG emissions related to energy (both 1%) when compared to its use in the US’s total energy supply (2%).