# 1048.805 What symbols, acronyms, and abbreviations does this part use?
The following symbols, acronyms, and abbreviations apply to this part:
°C degrees Celsius.
ASTM American Society for Testing and Materials.
cc cubic centimeters.
CFR Code of Federal Regulations.
CH<sub>4</sub> methane.
cm centimeter.
CO carbon monoxide.
CO<sub>2</sub> carbon dioxide.
EPA Environmental Protection Agency.
g/kW-hr grams per kilowatt-hour.
HC hydrocarbon.
ISO International Organization for Standardization.
kPa kilopascals.
kW kilowatts.
LPG liquefied petroleum gas.
m meters.
MIL malfunction-indicator light.
mm Hg millimeters of mercury.
N<sub>2</sub>O nitrous oxide.
NARA National Archives and Records Administration.
NMHC nonmethane hydrocarbons.
NO<sub>X</sub> oxides of nitrogen (NO and NO<sub>2</sub>).
psi pounds per square inch of absolute pressure.
psig pounds per square inch of gauge pressure.
rpm revolutions per minute.
SAE Society of Automotive Engineers.
SI spark-ignition.
THC total hydrocarbon.
THCE total hydrocarbon equivalent.
U.S.C. United States Code.
[67 FR 68347, Nov. 8, 2002, as amended at 70 FR 40485, July 13, 2005; 74 FR 56510, Oct. 30, 2009]