The following symbols, acronyms, and abbreviations apply to this part:

CFR   Code of Federal Regulations.

CH4   methane.

CO   carbon monoxide.

CO2   carbon dioxide.

DEF   Diesel exhaust fluid.

EEFM   Emergency equipment field modification.

EPA   Environmental Protection Agency.

FEL   Family Emission Limit.

g/kW-hr   grams per kilowatt-hour.

HC   hydrocarbon.

ISO   International Organization for Standardization (see www.iso.org).

kW   kilowatts.

N2O   nitrous oxide.

NIST   National Institute of Standards and Technology.

NMHC   nonmethane hydrocarbons.

NOX   oxides of nitrogen (NO and NO2).

NTE   not-to-exceed

PM   particulate matter.

rpm   revolutions per minute.

SAE   Society of Automotive Engineers.

SCR   Selective catalytic reduction.

SEA   Selective enforcement audit.

THC   total hydrocarbon.

THCE   total hydrocarbon equivalent.

TRU   transportation refrigeration unit.

U.S.C.   United States Code.

[69 FR 39213, June 29, 2004, as amended at 74 FR 56509, Oct. 30, 2009; 77 FR 34148, June 8, 2012]


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