Tropospheric ozone (smog) is formed when volatile organic compounds (VOCs), oxygen, and NOx react in the presence of sunlight (not to be confused with stratospheric ozone, which is found in the upper atmosphere and protects the earth from the sun's ultraviolet rays). Though beneficial in the upper atmosphere, ground-level ozone is a respiratory irritant and considered a pollutant.
Fuels blended with an additive, usually methyl tertiary butyl ether (MTBE) or ethanol to increase oxygen content, allowing more thorough combustion for reduced carbon monoxide emissions.
A term used in the petroleum industry to denote fuel additives containing hydrogen, carbon, and oxygen in their molecular structure. Includes ethers such as MTBE and ETBE and alcohols such as ethanol and methanol.
Regulated air pollutants, primarily NO and NO2 but including other substances in minute concentrations. Under the high pressure and temperature conditions in an engine, nitrogen and oxygen atoms in the air react to form various NOx. Like hydrocarbons, NOx are precursors to the formation of smog. They also contribute to the formation of acid rain.
A valve installed at the fill port of an above ground storage tank to terminate product flow when the liquid level reaches a preset level. Other methods include but are not limited to berms, liners and other secondary containment should a leak or spill occur and overfill alarms. Overfill alarms use probes installed in the tank to activate an alarm when the tank is either (approximately) 90 percent full or within 1 minute of being overfilled.
The original manufacturer of a vehicle or engine.
System in which the air/fuel mixture is preset by design with no feedback correction signal to optimize fuel metering.
System required on vehicles beginning in 1998 to control refueling emissions.
Division of EPA that protects public health and the environment by controlling air pollution from motor vehicles, engines, and the fuels used to operate them, and by encouraging travel choices that minimize emissions.
Any non-stationary device, powered by an internal combustion engine or motor, used primarily off the highways to propel, move, or draw persons or property, and used in any of the following applications: marine vessels, construction/farm equipment, locomotives, utility and lawn and garden equipment, off-road motorcycles, and off-highway vehicles.