42 U.S.C. § 7521 — Emission standards for new motor vehicles or new motor vehicle engines

(a) Authority of Administrator to prescribe by regulation (1) The Administrator must set rules limiting air pollution from new motor vehicles and new motor vehicle engines. This applies to any pollutant that, in the Administrator's judgment, may reasonably endanger public health or welfare. The rules must cover the vehicle's "useful life," a period defined in subsection (d). This applies whether the vehicle is a complete system or simply has pollution-control add-ons. (2) A new rule, or a revision, only takes effect after enough time passes for manufacturers to develop and use the needed technology. The Administrator must weigh the cost of compliance when setting that timeline. (3)(A) For heavy-duty vehicles and engines made in model year 1983 or later, standards for hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter must reflect the greatest emission cuts achievable with available technology for that model year — while giving fair weight to cost, energy, and safety. The Administrator can group vehicles into classes by weight, horsepower, fuel type, or similar factors. (B) The Administrator can revise older heavy-duty truck standards, weighing costs, based on new information about health and welfare effects. Starting with model year 1998, gasoline and diesel heavy-duty trucks cannot emit more than 4.0 grams of nitrogen oxides per brake horsepower-hour. (C) Any standard for heavy-duty vehicles must stay in place for at least 3 model years. It can't start earlier than 4 years after the Administrator sets it. (D) The Administrator must study how rebuilding heavy-duty engines affects their emissions, and may then set rules — including emission standards — for rebuilt engines, even ones already past their useful life, if they threaten public health. Any such rule needs enough lead time for compliance, weighing cost, energy, and safety. (E) Motorcycles are treated like heavy-duty vehicles for this paragraph, unless the Administrator reclassifies them as light-duty or sets separate motorcycle standards. If the Administrator does set separate motorcycle standards, they must try to make motorcycle emission cuts roughly equal to those for other vehicles. (4)(A) Starting with vehicles made after model year 1978, no emission-control device or design can be used if it creates an unreasonable risk to public health, welfare, or safety. (B) To decide if a risk is "unreasonable," the Administrator must weigh: whether the device changes emissions of unregulated pollutants; what methods exist to reduce any resulting risk; and whether other devices could meet the standards without the risk. The Administrator must also consider all relevant information gathered under section 7548. (5)(A) If the Administrator sets final rules defining gasoline vapor recovery requirements for refueling, the Administrator must then — after consulting the Secretary of Transportation on safety — set fill pipe standards so fill pipes connect properly to vapor recovery systems. These standards can address pipe diameter, nozzle retainer design, fuel restrictor placement, clearance space, and insertion angle, among other things. (B) These fill pipe standards don't take effect until the model year for which they're actually feasible, given design and production lead time. (C) These standards can't force a specific fuel tank or fill neck design or styling. But the Administrator can require different nozzle and fill neck sizes for gasoline with additives versus without. (D) "Fill pipe" means the fuel tank's fill pipe, fill neck, fill inlet, and closure, together. (6) Within 1 year of November 15, 1990, and after consulting the Secretary of Transportation on safety, the Administrator had to set standards requiring new light-duty vehicles — starting in the fourth model year after the standards are set — to have onboard systems that capture refueling vapor. The phase-in covers a rising share of each manufacturer's sales: 40% in the fourth model year, 80% in the fifth, and 100% after that. These onboard systems must capture at least 95% of evaporative emissions. Once these systems are common, older gas-pump-based ("Stage II") vapor recovery rules for moderate-ozone areas stop applying, and the Administrator can adjust or waive them for areas with worse ozone problems. (b) Emissions of carbon monoxide, hydrocarbons, and oxides of nitrogen; annual report to Congress; waiver of emission standards; research objectives (1)(A) For light-duty vehicles made in model years 1977 through 1979, hydrocarbon emissions can't exceed 1.5 grams per mile, and carbon monoxide can't exceed 15.0 grams per mile. For model year 1980, carbon monoxide can't exceed 7.0 grams per mile. Starting model year 1980, hydrocarbon standards must cut emissions by at least 90% compared to the model year 1970 standard. Starting model year 1981, carbon monoxide standards must also cut emissions by at least 90% compared to 1970 — unless waived, as described below. (B) For model years 1977 through 1980, nitrogen oxide emissions can't exceed 2.0 grams per mile. Starting model year 1981, the limit drops to 1.0 gram per mile. But a small manufacturer — one that made fewer than 300,000 light-duty vehicles worldwide in 1976 — can get a looser 2.0 gram limit for 1981 and 1982, if the Administrator finds that manufacturer depended on buying technology from others to meet emissions rules, and lacks the money and technical ability to develop its own. (C) The Administrator can later revise these standards to protect health or welfare, weighing cost, energy, and safety — but any revision must make emissions stricter, not looser, and can be phased in. Congress intended that the specific numeric standards in subsections (a)(3)(B)(ii), (g), (h), and (i) stay fixed for any model year before 2004. (2) The Administrator had 180 days from November 15, 1990 to finish setting these standards and measurement methods, if not already done. (3)(A)(i) "Model year" usually means a manufacturer's own annual production period that includes January 1 of that year. If a manufacturer has no such period, "model year" means the calendar year. (ii) To stop manufacturers from gaming this definition, the Administrator can define "model year" differently by regulation. (B) This provision was repealed by a 1990 law. (C) A "heavy duty vehicle" is a truck, bus, or similar road vehicle — not one that runs only on rails — weighing more than 6,000 pounds, as the Administrator measures it. This includes vehicles specially built for off-road use too. The source text also contains a separate waiver rule, also labeled paragraph (3): on a manufacturer's request, after notice and a public hearing, the Administrator can waive the nitrogen oxide standard down to no stricter than 1.5 grams per mile for up to four model years after 1980. This only applies to a class of vehicles using new, innovative engine or emission-control technology that fewer than 1% of 1975 light-duty vehicles used. The Administrator can only grant this waiver if: (A) it won't endanger public health; (B) the vehicles are substantially likely to meet the regular standard once the waiver ends; and (C) the technology has long-term air-quality benefits and could meet fuel economy standards under the Energy Policy and Conservation Act once the waiver ends. This waiver can't cover more than 5% of the manufacturer's production, or 50,000 vehicles or engines, whichever number is bigger. (c) Feasibility study and investigation by National Academy of Sciences (1) The Administrator must arrange for the National Academy of Sciences to study whether the subsection (b) emission standards are technologically achievable. (2) Money for this study comes from funds Congress appropriates for this purpose. (3) The Administrator must ask the Academy for progress reports to the Administrator and Congress every six months, starting no later than July 1, 1971, until the study is done. (4) The Administrator must give the Academy any information it needs for the study, using the Administrator's legal power to gather information and require testing, recordkeeping, and reporting from any person. (d) Useful life of vehicles The Administrator must set rules defining "useful life" for purposes of subsection (a)(1) and section 7541. Unless a different period is specified elsewhere: (1) For light-duty vehicles and light-duty trucks up to 3,750 pounds loaded weight and 6,000 pounds gross weight, useful life is 5 years or 50,000 miles, whichever comes first. But for requirements that first applied after November 15, 1990, without their own stated useful life, it's 10 years or 100,000 miles, whichever comes first — though in-use compliance testing only goes up to 7 years or 75,000 miles. (2) For other vehicles and engines, except motorcycles, useful life matches paragraph (1) unless the Administrator decides a longer period fits. (3) For motorcycles, the Administrator decides the useful life period. (e) New power sources or propulsion systems If someone submits a genuinely new kind of engine or power source for certification, and the Administrator hasn't yet set pollution standards for what it emits, the Administrator can delay certifying it until standards exist. (f) High altitude regulations (1) The high-altitude rule that applied to 1977 vehicles stopped applying to 1978-and-later vehicles. Any future high-altitude rule for vehicles made before model year 1984 can't take effect before model year 1981. (2) A future high-altitude rule can't demand a bigger percentage emission cut than subsection (b) generally requires, measured against 1970 model year emissions. And for vehicles made before 1984, a high-altitude standard can never be numerically stricter than the regular, non-high-altitude standard. (3) The formal rulemaking process in section 7607(d) applies to these high-altitude rules. Before issuing one, the Administrator must weigh: (A) the economic impact on consumers, high-altitude dealers, and the industry, including what happened after the 1977 high-altitude rule; (B) whether emission-control technology exists that won't cut down which models are available; and (C) whether the rule would meaningfully improve air quality where it applies. (g) Light-duty trucks up to 6,000 lbs. GVWR and light-duty vehicles; standards for model years after 1993 (1) Starting model year 1994, standards for nonmethane hydrocarbons, carbon monoxide, and nitrogen oxides from these vehicles must follow "Table G," phased in over each manufacturer's sales: 40% in 1994, 80% in 1995, 100% after 1995. Table G sets two useful-life tracks — a 5-year/50,000-mile column and a 10-year/100,000-mile column — with separate limits for two weight classes of light truck. Before 2004, diesel-fueled light trucks and light vehicles in the lighter weight class get looser nitrogen oxide numbers than the general standard. (2) Starting model year 1994 for light-duty vehicles, and 1995 for light-duty trucks up to 6,000 pounds, particulate matter can't exceed 0.08 grams per mile over a 5-year/50,000-mile useful life, or 0.10 grams per mile over 10 years/100,000 miles. This phases in on its own schedule, reaching 100% for vehicles by 1996 and for trucks after 1996. (h) Light-duty trucks of more than 6,000 lbs. GVWR; standards for model years after 1995 Starting model year 1996, hydrocarbon, carbon monoxide, nitrogen oxide, and particulate matter standards for these heavier light-duty trucks follow "Table H," covering two weight classes and two useful-life tracks (5-year/50,000-mile and 11-year/120,000-mile). The nitrogen oxide numbers in Table H don't apply to diesel-fueled trucks. Half of each manufacturer's sales must comply starting 1996, and all of them after that. (i) Phase II study for certain light-duty vehicles and light-duty trucks (1) The Administrator, working with the Office of Technology Assessment, had to study whether to require further emission cuts, starting with model years after January 1, 2003, for gasoline and diesel vehicles weighing 3,750 pounds loaded or less. The study had to consider a specific set of numbers, called "Table 3": 0.125 grams per mile of nonmethane hydrocarbons, 0.2 grams per mile of nitrogen oxides, and 1.7 grams per mile of carbon monoxide, with a 10-year/100,000-mile useful life. The study also had to look at other standards, both stricter and looser than Table 3, as long as they were still stricter than the existing (g) and (h) standards. (2)(A) As part of the study, the Administrator had to look at whether further cuts were needed to meet national air quality standards, and examine the availability and cost of the needed technology for standards starting no earlier than 2003 and no later than 2006, plus the cost-effectiveness of getting those extra reductions. (B) The Administrator had to report to Congress by June 1, 1997, including a summary of public comments gathered first. (3)(A) Based on that study, the Administrator had to decide by rule — within 3 years of the report, and no later than December 31, 1999 — whether further reductions were needed, whether the technology would be available in time, and whether the reductions would be cost-effective. This rulemaking had to start within 3 months of the report going to Congress. (B) If the Administrator found reductions weren't needed, the technology wouldn't be ready, or the reductions wouldn't be cost-effective, the Administrator could not adopt standards stricter than the existing (g) and (h) rules through this process — though the Administrator could still act later using the general power in subsection (a). (C) If the Administrator found reductions were needed, the technology would be ready, and the reductions would be cost-effective, the Administrator had to adopt either the Table 3 standards or an equally strict or stricter alternative, effective sometime between model years 2003 and 2006. (D) Nothing here means Table 3's numbers are automatically presumed correct. But the duty to make this decision counts as mandatory for citizen-suit purposes under section 7604(a)(2). (E) Unless the Administrator decided not to adopt stricter standards, or to delay them, or to adopt an alternative, the Table 3 standards took effect automatically for model years starting after January 1, 2003. (j) Cold CO standard (1) Phase I: Within 12 months of November 15, 1990, the Administrator had to set standards for carbon monoxide emissions at 20°F from 1994-and-later light-duty vehicles and trucks. The limit is 10.0 grams per mile for light-duty vehicles, and a comparably strict limit for light-duty trucks. This phases in starting model year 1994: 40% of sales in 1994, 80% in 1995, 100% in 1996 and after. (2)(A) By June 1, 1997, the Administrator had to finish a study on whether further cold-weather carbon monoxide cuts were achievable for 2001-and-later vehicles. (B)(i) If, as of June 1, 1997, six or more nonattainment areas had a carbon monoxide design value of 9.5 parts per million or higher, then standards for 2002-and-later vehicles get tighter: 3.4 grams per mile for light-duty vehicles, 4.4 grams per mile for light-duty trucks up to 6,000 pounds, and a comparably strict number for heavier light-duty trucks. (ii) When counting those six-or-more areas, the Administrator must leave out Steubenville, Ohio, and Oshkosh, Wisconsin. (3) For both Phase I and Phase II cold-CO standards, the useful life is 5 years or 50,000 miles, unless the Administrator extends it because longer compliance is feasible — with matching standard adjustments — but never beyond the useful life set under subsection (d). (4) The Administrator may also set cold-temperature carbon monoxide rules for heavy-duty vehicles and engines. (k) Control of evaporative emissions The Administrator must regulate hydrocarbon evaporation from all gasoline vehicles, both while running and during 2 or more days of non-use, under summer ozone conditions. These rules must take effect as soon as possible and require the strongest emission cuts realistically available for production, weighing fuel volatility, cost, energy, and safety. The Administrator had to start this rulemaking within 12 months of November 15, 1990. If final rules weren't ready within 18 months, the Administrator had to explain the delay to Congress and set a firm new deadline, no more than 15 months past that 18-month mark. (l) Mobile source-related air toxics (1) Study: Within 18 months of November 15, 1990, the Administrator had to study whether and how to control unregulated toxic air pollutants from vehicles and vehicle fuels — focusing on the biggest health risks or the least understood ones, including benzene, formaldehyde, and 1,3-butadiene. This study had to go through public review and comment. (2) Standards: Within 54 months of November 15, 1990, based on that study, the Administrator had to set reasonable controls on hazardous air pollutants from vehicles and fuels, reflecting the strongest achievable emission cuts given available technology, cost, noise, energy, safety, and lead time. These rules must be consistent with the subsection (a) standards, and must, at minimum, cover benzene and formaldehyde. (m) Emissions control diagnostics (1) Within 18 months of November 15, 1990, the Administrator had to require manufacturers to install onboard diagnostic systems on all new light-duty vehicles and trucks. These systems must: (A) accurately detect emission-system deterioration or malfunction over the vehicle's useful life, covering at minimum the catalytic converter and oxygen sensor; (B) alert the owner that maintenance or repair may be needed; (C) store and retrieve fault codes the Administrator specifies; and (D) let that stored information be accessed in a way the Administrator specifies. The Administrator may also require these systems on heavy-duty vehicles and engines. (2) These rules took effect for model year 1994, though the Administrator could waive them for model year 1994 or 1995, or both, for a vehicle class, if applying them that soon would be infeasible — as long as the waiver matched California's own policy for these systems. (3) The Administrator must require states with vehicle inspection-and-maintenance programs in their air quality plans to update those plans within 2 years, to inspect these onboard systems and require repair of any problems they find. This can't conflict with the warranty rules in section 7541(a) and (b). (4) The Administrator's rules must require: (A) standard, uniform connectors for accessing the system across all vehicles; (B) unrestricted access through those connectors, with no special code or manufacturer-only device needed; and (C) data output that doesn't need any unique decoding device. (5) The Administrator must require manufacturers to promptly give repair people — and the Administrator — all information needed to use the diagnostic system and make repairs, subject to trade-secret protections under section 7542(c). But information the manufacturer already gives its own franchised dealers can't be withheld from independent repair shops under that trade-secret rule. Separately, later in the source text, there's a second provision also labeled "(f)," headed "Model years after 1990." It is a leftover rule about buses. For model years before 1994, buses not already covered by section 7554 standards face particulate matter limits: 0.25 grams per brake horsepower-hour in 1991, 0.25 in 1992, and 0.10 in 1993 and after.