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 2 = square 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: °C = degree Celsius (centigrade) cfm = cubic feet per minute cc = cubic centimeter Ci = curie d = day °F = degree Fahrenheit ft 2 = square feet ft 3 = cubic feet gal = gallon in = inch in Hg = inches of mercury in H 2 O = inches of water l = liter lb = pound lpm = liter per minute min = minute ml = milliliter = 10 −3 liter mrem = millirem = 10 −3 rem oz = ounces pCi = picocurie = 10 −12 curie psig = pounds per square inch gage °R = degree Rankine µl = microliter = 10 −6 liter v/v = volume per volume yd 2 = square yards yr = year (c) Chemical nomenclature: Be = beryllium Hg = mercury H 2 O = water (d) Miscellaneous: act = actual avg = average I.D. = inside diameter M = molar N = normal O.D. = outside diameter % = percent std = standard [42 FR 51574, Sept. 29, 1977, as amended at 54 FR 51704, Dec. 15, 1989]