Emissions Exhaust emissions from a typical NGV are much lower than those from gasoline-powered vehicles. However, exhaust emissions from a natural gas-powered Honda Civic GX are even lower. Environmental and Health Benefits Dedicated NGVs produce little or no evaporative emissions during fueling and use. In gasoline vehicles, evaporative and fueling emissions account for at least 50 percent of a vehicle's total hydrocarbon emissions. Exposure to the levels of suspended fine particulate matter found in many U.S. cities has been shown to increase the risk of respiratory illness.
Diesel exhaust is under review as a hazardous air pollutant.
Natural gas engines produce only tiny amounts of this matter. Safety CNG, unlike gasoline, dissipates into the atmosphere in the event of an accident. Gasoline pools on the ground creating a fire hazard. The fuel storage cylinders used in NGVs are much stronger than gasoline fuel tanks. Even if a leak were to occur in an NGV fuel system, the natural gas would dissipate into the atmosphere because it is lighter than air.