40 CFR § 60.3 - Units and abbreviations.

§ 60.3 Units and abbreviations.

Used in this part are abbreviations and symbols of units of measure. These are defined as follows:

(a) System International (SI) units of measure:

A - ampere
g - gram
Hz - hertz
J - joule
K - degree Kelvin
kg - kilogram
m - meter
m 3 - cubic meter
mg - milligram - 10 −3 gram
mm - millimeter - 10 −3 meter
Mg - megagram - 10 6 gram
mol - mole
N - newton
ng - nanogram - 10 −9 gram
nm - nanometer - 10 −9 meter
Pa - pascal
s - second
V - volt
W - watt
Ω - ohm
µg - microgram - 10 −6 gram

(b) Other units of measure:

Btu - British thermal unit
°C - degree Celsius (centigrade)
cal - calorie
cfm - cubic feet per minute
cu ft - cubic feet
dcf - dry cubic feet
dcm - dry cubic meter
dscf - dry cubic feet at standard conditions
dscm - dry cubic meter at standard conditions
eq - equivalent
°F - degree Fahrenheit
ft - feet
gal - gallon
gr - grain
g-eq - gram equivalent
hr - hour
in - inch
k - 1,000
l - liter
lpm - liter per minute
lb - pound
meq - milliequivalent
min - minute
ml - milliliter
mol. wt. - molecular weight
ppb - parts per billion
ppm - parts per million
psia - pounds per square inch absolute
psig - pounds per square inch gage
°R - degree Rankine
scf - cubic feet at standard conditions
scfh - cubic feet per hour at standard conditions
scm - cubic meter at standard conditions
sec - second
sq ft - square feet
std - at standard conditions

(c) Chemical nomenclature:

CdS - cadmium sulfide
CO - carbon monoxide
CO2 - carbon dioxide
HCl - hydrochloric acid
Hg - mercury
H2O - water
H2S - hydrogen sulfide
H2SO4 - sulfuric acid
N2 - nitrogen
NO - nitric oxide
NO2 - nitrogen dioxide
NOX - nitrogen oxides
O2 - oxygen
SO2 - sulfur dioxide
SO3 - sulfur trioxide
SOX - sulfur oxides

(d) Miscellaneous:

A.S.T.M. - American Society for Testing and Materials
[42 FR 37000, July 19, 1977; 42 FR 38178, July 27, 1977]

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