Document 2JkpGrZaJ9xXOvQdJwEZa2KXL

Table 3. Maximum Allowable Concentration op Gases and Vapors (Concluded) ' Substancb Aoa.qtaNdABDS MA.C. ppmb by voltune Threshold Limit Values A.C.GJ.H.* 1956 g/cu m or Oz/1000 cu ft 2-Nitropropane.. Nitrotoluene-- Octane................ Ozone.................. Pentane.............. Pentanone (methyl propyl ketone)....... Perchlorethylene (tetrachloroethylene). Phenol......................... ............................. (x) Phenylhydrazine....................................... Phosgene (carbonyl chloride). .............. Phosphine............................................ Phosphorus trichloride..................... Propyl acetate.................................... Propyl alcohol (isopropyl alcohol). Propyl ether (isopropyl ether)....... Propylene dichloride (1,2-dichloropropane).. (x) Propylene imine................................................. (x) Pyridine............................................................... (x) Quinone................................................................ Stibine.................................................................. Stoddard solvent.................................. Styrene monomer (phenylethylene). Sulfur dioxide....................................... (x) Sulfur hexafluoride.............................. Sulfur monochloride............................ (x) Sulfur pentafluoride............ (x) p-Tertiarybutyltoluene....... 1,1,2,2-Tetrachloroethane.. (x) Tetranitromethane.............. Toluene (toluol).................. o-Toluidine.................................... Trichloroethylene......................... (a) Trifluoromonobromomethaae__ Turpentine..................................... Vinyl chloride (chloroethylene). Xylene (xylol). GO 5 GOO 0.1 1000 200 200 5 5 1 0.05 0.5 200 400 500 75 25 10 0.1 0.1 500 200 10 1000 1 0.025 10 5 1 200 5 200 1000 100 500 200 0.180 0.030 2.350 0.0002 2.950 0.700 1.350 0.019 0.022 0.004 0.00007 0.003 0.840 0.980 2.100 0.350 0.060 0.030 0.0004 0.0005 2.90 0.850 0.025 6.000 0.006 0.00025 0.060 0.035 0.008 0.750 0.022 1.050 6.100 0.560 1.30 0.870 * A.C.G.I.H. = American Conference of Governmental Industrial Hy&ienieta. Reprinted by permission - from AM.A. Archives of Industrial Health, August 1956, VoL 14, pp. 186-189. b Parte of vapor or gas per million parts of air by volume. (x) These values appeared in A.C.GJ.H. tentative list for 1955. - apply a reasonable safety factor to the ventilation estimate without con- ^ sideration of the concentrations of gases or vapors that approach the danger , point. Safety engineers prefer to limit the concentration to or J of the? lower explosive limit, and this fact should be given full weight in determine ing the capacity and design of ventilating equipment. Rarely shouldj consideration be given to' operation above the vpper ex-plosive limit in the; open areas of buildings or rooms---even though unoccupied--because the ; danger of temporary drop of gas concentration to a point within the ex- ; plosive range is too great. Ability of a flammable liquid to form explosive mixtures is determined largely by its vapor pressure, volatility, or rate of evaporation. Flash point is a convenient method of expressing this property in terms of the,': temperature scale. It may be defined as the temperature to which a com-; bustible liquid must be heated to produce a flash when a small flame is) passed across the surface of the liquid. The higher the flash point, the; Air Contaminants 161 Table 4. Limits for Toxic Dusts, Fumes and Mists Substance A.S.A. Standards Threshold Limit M.A.C, Values, A.C.GJJI g/cu ma 1956 g/cu m* (x) Aldrin (1,2,3,4,10,1Q-hex&chloro-1,4,4a,5,8,8a-hexahydro1,4,5,8-dimethanonaphthalene)................................................... (x) Animate (ammonium sulfamate)................................................... Antimony.............................................................................-............... Arsenic.................................................................................................. Barium (soluble compounds)........................................................... Cadmium oxide fume........................................................................ (x) Chlordane (l^^.S.e^.S.S-octachloro-Sa^.T^a-tetrahydro- 4,7-methanomdane)................................................................ . (x) Chlorinated diphenyl oxide............................................................. Chlorodiphenyl (42% chlorine)........................................................ Chromic acid and chromates (as CrO)........................................ (x) Crag herbicide (sodium 2-[2,4-dichlorophenoxy] ethanol hy drogen sulfate........ ................. ............................. ....................... Cyanide (as CN)................................................... ......................... 0.0001 0.00025 0.015 0.0005 0.0005 0.0005 0.0001 0.002 0.0005 0.001 0.0001 0.015 (x) 2,4-D(2,4-dicb!orophenoxyacetic acid).......................................... (x) Dieldrin (l,2,3,4,l0,10-hexachloro-6,7-epoxy-l,4,4a,5,6,7,8,8a-octahydro-1,4,5,8-dimethanonaphthalene).......................... Dinitrotoluene......................................... ........................................ Dinitro-o-cresol................................................................................... (x) EPN (O-ethyl O-p-nitrophenyl thionobenzenephosphonate).. (x) Ferrovanadium dust............................................................ ........... Fluoride................................................................................................ (x) Hydroquinone..................................................................................... Iron oxide fume................................................................................... Lead..................................................................................................... . (x) lindane (hexachlorocydohexane, gamma isomer)...................... Magnesium oxide fume..................................................................... (x) Malathion (O,O-dimethyl dithiophosphate of diethyl mercaptosuccinate)...................................................................................... Manganese............................................................................................ Mercury................................................................................................ (x) Mercury (organic compounds)................................... .................. (x) Methoxychlor (2,2-di-p-methoxyphenyH,l ,1-txichloroeth. ane).................................................................................................... (x) Molybdenum , (soluble compounds)............................................................. (insoluble compounds)............................................... Parathion (0,0-diethyl O-p-nitropbenyl thiophosphate) `Pentachloronaphthalene.......................................................... 0.00015 0.006 0.0001 0.010 0.00025 0.0015 0.0002 0.0005 0.001 0.0025 0.002 0.015 0.00015 0.0005 0.015 0.015 0.006 0.0001 0.00001 0.015 0.005 0.015 0.0001 Pentachlorophenol..................................................................... Phosphorus (yellow)................................................................. Phosphorus pentachloride........................................................ Phosphorus pentasulflde.......................................................... to Picric acid................................................................................... to Selenium compounds (as Se)......................... Sodium hydroxide..................... *...... ........... Sulfuric acid.............................................. to TEDP (tetraethyl ditbionopyrophospbate) to TEPP (tetraethyl pyrophosphate)............. Tellurium.............................................. . -- -.- Tetryl (2,4,6-trinitxophenylmethylnitramme) (x) Titanium dioxide.................................................. Trichloronaphthalene........................................... Trinitrotoluene...................................................... Uranium.................. (solub lo compounds)... W Va<SuuUmeC"P0Und3> 0.0005 0.0001 0.001 0.001 0.0001 0.0001 0.002 0.001 0.0002 0.00005 0.0001 0.0015 0.015 0.005 0.0015 CVrf). dust)................ ,,.(V0* fume)........................... fxl xide fumes................. x > *ircomum compounds (as Zr) 0.0005 0.0001 0.015 0.005 (J?t?8 d,ust fume, or mist per cubic meter of air. HadhtaMSJ* US? appeared on the A.C.G.I.H. tentative list, for 1955, of RadioL^t Vl- permissible concentrations of radioisotopes in air, isee "Maximum Permissible Amounts book 52 R^n111 the Human tooddyy^antd1 MMaaxxiimmum PermiissriblejConcentrationssJin Air and Water," Hand`'Permit;hh> A UePartm^nt Commerce, National Bureau of Standards. March. 1953. In addition, 'mneererc* eVr.i.-l.T?^ 1f1rWoAm11 jEjxatuesriniuaul oSoouiurcweas ooif lIuomniazuinigg xRvaudiiation," Handbook 59, U. S. Department of (Com- Table 4^1 Surea* of Standards, September 24, 1954. PP- 186-189. 063 reprinted hy Permission from AM.A. Archives of Industrial Health, August 1956, Vol. 14