CLEAN AIR ACT AMENDMENTS OF 1990 GLOSSARY OF TERMS ACID DEPOSITION ("ACID RAIN"). -- A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere, often far from the original sources, and then deposited on earth in either a wet or dry form. The wet forms, popularly called "acid rain," can fall as rain, snow, or fog. The dry forms are acidic gases or particulates. AIR TOXICS. -- Any air pollutant for which a national ambient air quality standard (NAAQS) does not exist (i.e. excluding ozone, carbon monoxide, PM-10, sulfur dioxide, nitrogen dioxide) that may reasonably be anticipated to cause cancer, developmental effects, reproductive dysfunctions, neurological disorders, heritable gene mutations or other serious or irreversible chronic or acute health effects in humans. AROMATICS. -- A type of hydrocarbon, such as benzene or toluene, added to gasoline in order to increase octane. Some aromatics are toxic. ATTAINMENT AREA. -- An area considered to have air quality as good as or better than the National Ambient Air Quality Standards as defined in the Clean Air Act. An area may be an attainment area for one pollutant and a non-attainment area for others. BEST AVAILABLE CONTROL MEASURE (BACM). -- A term used in the House bill referring to the "best" measures (according to EPA guidance) for controlling small or dispersed sources of particulate matter, such as roadway dust, woodstoves, and open burning. CARBON MONOXIDE (CO). -- A colorless, odorless gas which is toxic because of its tendency to reduce the oxygen-carrying capacity of the blood. CLEAN COAL TECHNOLOGY. -- Any technology not in widespread use as of the date of enactment of the Clean Air Act amendments which will achieve significant reductions in pollutants associated with the burning of coal. CLEAN FUELS. -- Blends and/or substitutes for gasoline fuels. These include compressed natural gas, methanol, ethanol, and others. COKE OVEN. -- An industrial process which converts coal into coke, which is one of the basic materials used in blast furnaces for the conversion of iron ore into iron. COLD TEMPERATURE CO. -- A standard for automobile emissions of carbon monoxide (CO) to be met at a low temperature (i.e., 20 degrees F). Conventional catalytic converters are less efficient upon start-up at low temperatures. CONTROL TECHNIQUES GUIDELINE (CTG). -- Guidance documents issued by EPA which define reasonably available control technology (RACT) to be applied to existing facilities that emit certain threshold quantities of air pollutants; they contain information both on the economic and technological feasibility of available techniques. CFCS (CHLOROFLUOROCARBONS). -- A family of inert, nontoxic, and easily-liquefied chemicals used in refrigeration, air conditioning, packaging, insulation, or as solvents or aerosol propellants. Because CFCs are not destroyed in the lower atmosphere they drift into the upper atmosphere where the chlorine is released and destroys ozone. CFC-12. -- A chlorofluorocarbon with a trademark name of Freon, commonly used in refrigeration and automobile air conditioning. EMISSION CONTROL DIAGNOSTICS. -- Computerized devices placed on vehicles to detect malfunction of emissions controls and notify the owner of the need for repair. ENHANCED INSPECTION & MAINTENANCE (ENHANCED I&M). -- An improved automobile inspection and maintenance program that includes, as a minimum, increases in coverage of vehicle types and model years, tighter stringency of inspections and improved management practices to ensure more effectiveness. This may also include annual, computerized, or centralized inspections; under-the-hood inspections to detect tampering with pollution control equipment; and increased repair waiver cost. The purpose of Enhanced I&M is to reduce automobile emissions by assuring that cars are running properly. FEDERAL IMPLEMENTATION PLAN (FIP). -- Under current law, a federally implemented plan to achieve attainment of an air quality standard, used when a state is unable to develop an adequate plan. Under the Senate bill, a plan containing control measures developed and promulgated by EPA in order to fill gaps in a State Implementation Plan (SIP). GASOLINE VOLATILITY. -- The property of gasoline whereby it evaporates into a vapor. Gasoline volatility is measured in pounds per square inch (psi), with a higher number reflecting more gasoline evaporation. Gasoline vapor is a volatile organic compound (VOC). HALONS. -- A family of compounds containing bromine used in fighting fires, whose breakdown in the atmosphere depletes stratospheric ozone. HCFCs. -- Chlorofluorocarbons that have been chemically altered by the addition of hydrogen, and which are significantly less damaging to stratospheric ozone than other CFCs. INSPECTION & MAINTENANCE (I&M). -- A program providing for periodic inspections of motor vehicles to ensure that emissions of specified pollutants are not exceeding established limitations. LOW NOX BURNERS. -- One of several combustion technologies used to reduce emissions of NOx. MAXIMUM ACHIEVABLE CONTROL TECHNOLOGY (MACT). -- Emissions limitations based on the best demonstrated control technology or practices in similar sources to be applied to major sources emitting one or more of the listed toxic pollutants. MONTREAL PROTOCOL. -- An international environmental agreement to control chemicals that deplete the ozone layer. The protocol, which was renegotiated in June 1990, calls for a phase-out of CFCs, halons, and carbon tetrachloride by the year 2000, a phase-out of chloroform by 2005, and provides financial assistance to help developing countries make the transition from ozone-depleting substances. NOx (NITROGEN OXIDES). -- Chemical compounds containing nitrogen and oxygen; reacts with volatile organic compounds, in the presence of heat and sunlight to form ozone. It is also a major precursor to acid rain. Nationwide, approximately 45 percent of NOx emissions come from mobile sources, 35 percent from electric utilities, and 15 percent from industrial fuel combustion. ONBOARD CONTROLS. -- Devices placed on vehicles to capture gasoline vapor during refueling and then route the vapors to the engine when the vehicle is started so that they can be efficiently burned. OXYGENATED FUELS. -- Gasoline which has been blended with alcohols or ethers that contain oxygen in order to reduce carbon monoxide and other emissions. OZONE. -- A compound consisting of three oxygen atoms, that is the primary constituent of smog. It is formed through chemical reactions in the atmosphere involving volatile organic compounds, nitrogen oxides, and sunlight. Ozone can initiate damage to the lungs as well as damage to trees, crops, and materials. There is a natural layer of ozone in the upper atmosphere which shields the earth from harmful ultraviolet radiation. PM-10. -- A new standard for measuring the amount of solid or liquid matter suspended in the atmosphere ("particulate matter"). Refers to the amount of particulate matter over 10 micrometers in diameter. The smaller PM-10 particles penetrate to the deeper portions of the lung, affecting sensitive population groups such as children and people with respiratory diseases. REASONABLY AVAILABLE CONTROL MEASURES (RACM). -- A broadly defined term referring to technologies and other measures that can be used to control pollution; includes Reasonably Available Control Technology and other measures. In the case of PM-10, it refers to approaches for controlling small or dispersed source categories such as road dust, woodstoves, and open burning. REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT). -- An emission limitation on existing sources in non-attainment areas, defined by EPA in a Control Techniques Guideline (CTG) and adopted and implemented by States. REFORMULATED GASOLINE. -- Gasoline with a different composition from conventional gasoline (e.g., lower aromatics content) and that results in the production of lower levels of air pollutants. REPOWERING. -- The replacement of an existing coal-fired boiler with one or more clean coal technologies, in order to achieve significantly greater emission reduction relative to the performance of technology in widespread use as of the enactment of the Clean Air Act amendments. RESIDUAL RISK. -- The quantity of health risk remaining after application of the MACT (Maximum Achievable Control Technology). SANCTIONS. -- Actions taken against a state or local government by the Federal government for failure to plan or to implement a SIP. Examples include withholding of highway funds and a ban on construction of new sources. STAGE II CONTROLS. -- Systems placed on service station gasoline pumps to control and capture gasoline vapors during automobile refueling. STATE IMPLEMENTATION PLAN (SIP). -- Document prepared by states, and submitted to EPA for approval, which identifies actions and programs to be undertaken by the State and its subdivisions to implement their responsibilities under the Clean Air Act. SULFUR DIOXIDE (SO2). -- A heavy, pungent, colorless air pollutant formed primarily by the combustion of fossil fuels. It is a respiratory irritant, especially for asthmatics and is the major precursor to the formation of acid rain. TRANSPORTATION CONTROL MEASURES (TCMs). -- Steps taken by a locality to adjust traffic patterns (e.g., bus lanes, right turn on red) or reduce vehicle use (ridesharing, high-occupancy vehicle lanes) to reduce vehicular emissions of air pollutants. VEHICLE MILES TRAVELLED (VMT). -- A measure of both the volume and extent of motor vehicle operation; the total number of vehicle miles travelled within a specified geographical area (whether the entire country or a smaller area) over a given period of time. VOLATILE ORGANIC COMPOUNDS (VOCs). -- A group of chemicals that react in the atmosphere with nitrogen oxides in the presence of heat and sunlight to form ozone; does not include methane and other compounds determined by EPA to have negligible photochemical reactivity. Examples of VOCs include gasoline fumes and oil-based paints.