ARM 17.74.102. OCCUPATIONAL AIR CONTAMINANTS

(1) The purpose of this rule is to establish maximum threshold limit values for air contaminants under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse health effects. (a) The public is advised that regulations adopted by the United States secretary of labor pursuant to the federal Occupational Safety and Health Act (OSHA) may have pre-empted the application of some of these standards to certain workers in Montana. For those air contaminants for which an OSHA standard has been adopted, the OSHA standard applies to all workers in Montana except workers of state and local governments whose coverage is excluded by federal law and those workers whose work place is not of sufficient size to subject it to OSHA. For those air contaminants for which no OSHA standard has been adopted, the threshold limit values adopted by this rule apply to all workers in Montana. (b) Threshold limit values for air contaminants are established in this rule as ceiling ("C") values, or as time-weighted average values. (2) As used in this rule, the following definitions apply in addition to those in 50-70-103, MCA: (a) "ANSI" means the American National Standards Institute, of 1430 Broadway, New York, New York, 10018. (b) "Ceiling value" or an air contaminant preceded by a "C" means that for that air contaminant a threshold limit value has been established in this rule which value cannot be exceeded at any time, even briefly. (c) "mg/m 3 " means approximate milligrams of particulate per cubic meter of air. (d) "mppcf" means millions of particles per cubic feet of air based on impinger samples counted by light-field technics. (e) "ppm" means parts of vapor or gas per million parts of contaminated air by volume at 25 ?Celsius and 760 mmHg pressure. (f) "Time weighted average value" means that for an air contaminant for which such threshold limit value has been established in an 8-hour work shift a worker may be exposed to a single brief concentration which exceeds this value so long as the average 8-hour cumulative exposure as computed by the formula in (4) of this rule does not exceed this value. (3) When any worker employed at any work place is or would be exposed to an air contaminant exceeding the threshold limit values of this rule, the employer shall determine and implement feasible administrative or engineering controls first to reduce the air contaminant levels. If such controls fail to reduce the worker's exposure to air contaminant levels within the threshold limit values of this rule, personal protective equipment shall be provided by the employer for the worker and used to reduce the worker's exposure to air contaminants within the levels permitted by this rule. All personal protective equipment used for purposes of this rule must be approved for each particular use by a competent industrial hygienist or other technically qualified person. Whenever respirators are used as personal protective equipment, they must be satisfactory to the department. Questions as to whether respirators are satisfactory may be answered by contacting the Department of Environmental Quality, PO Box 200901, Helena, MT 59620-0901, phone (406)444-3671. (4) A worker's exposure to any air contaminant listed in Tables I, II, or III of this rule shall be limited in accordance with the requirements of this subsection. The exposure of a worker is to be calculated in relation to a single air contaminant and also in relation to a combination or mixture of air contaminants in an 8-hour period. (a) An employer shall use the following formula to compute a worker's cumulative or time weighted average exposure to a single air contaminant during an 8-hour work shift: (i) E = CaTa + CbTb + .... CnTn/8. "E" is the equivalent exposure for the working shift; "C" is the concentration during any period of time T where the concentration remains constant; and "T" is the duration in hours of the exposure at the concentration C. An employer shall not allow the value of E to exceed the 8-hour time weighted average limit in Tables I, II or III of this rule for the material involved. (ii) To illustrate the formula prescribed in (i) above, note that isoamyl acetate has an 8-hour time weighted average limit of 100 ppm in Table I. Assume that an employee is subject to the following exposure: 2 hours exposure at 150 ppm; 2 hours exposure at 75 ppm; 4 hours exposure at 50 ppm. Substituting this information in the formula, we have 2 x 50 + 2 x 75 + 4 x 50/8 = 81.25 ppm. Since 81.25 ppm is less than 100 ppm, the 8-hour time weighted average limit, the exposure is acceptable. (b) An employer shall use the following formula to compute a worker's cumulative or time weighted average exposure to a mixture or combination of air contaminants during an 8-hour work shift: (i) Em = C 1 /L 1 + C 2 /L 2 + .... C n L n . "Em" is the equivalent exposure for the mixture; "C" is the concentration of a particular air contaminant; and "L" is the threshold limit value for that contaminant from Tables I, II, or III of this rule. An employer shall not allow the value of Em to exceed unity (1) . (ii) The following example illustrates the formula prescribed in (i) above. Assume that a worker was exposed to actual concentrations of 500 ppm of acetone as listed in Table I, 45 ppm of 2-Butanone as listed in Table I, and 40 ppm of toluene as listed in Table II, during an 8-hour period. The 8-hour time weighted average exposure limits for these air contaminants are 1000 ppm, 200 ppm, and 200 ppm, respectively. Putting this data into the formula, Em = 500/1000 + 45/200 + 40/200, or 0.925. Since Em is less than unity (1) , the exposure of the worker to the combination or mixture of air contaminants is acceptable. (5) No person may cause or permit the exposure of any worker employed at any work place by inhalation, ingestion, skin absorption or contact to air contaminant levels in excess of the threshold limit values listed in this rule. Compliance with this rule shall be determined by calculating the worker's exposure to air contaminants as individual substances or as the exposure to a mixture of substances according to the formulas stated in (4) of this rule. (a) The threshold limit values in Table I of this rule are to be interpreted as follows: (i) A worker's exposure to any air contaminant in Table I, the name of which is preceded by a "C", e.g., C boran trifluoride, shall at no time exceed the threshold limit value listed which is expressed as a ceiling value for that air contaminant. (ii) A worker's exposure to any material in Table I, the name of which is not preceded by a "C", shall not exceed the threshold limit value which is expressed as an 8-hour time weighted average. (b) The threshold limit values in Table II of this rule are to be interpreted as follows: (i) A worker's exposure to any air contaminant listed in Table II, in any 8-hour work shift of a 40-hour work week, shall not exceed the 8-hour time weighted average limit given for that air contaminant in Table II. (ii) A worker's exposure to an air contaminant listed in Table II shall not exceed at any time during an 8-hour shift the acceptable ceiling concentration limit given for an air contaminant in Table II, except for a time period, and up to a concentration not exceeding the maximum duration and concentration allowed in the column under "acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift." (iii) To exemplify (i) and (ii) above, during an 8-hour shift, a worker may be exposed to a concentration of benzene above 25 ppm, but never above 50 ppm, only for a maximum period of 10 minutes. Such exposure must be compensated by exposures to concentrations less than 10 ppm so that the cumulative exposure for the entire 8-hour work shift does not exceed a time weighted average of 10 ppm. (c) The threshold limit values in Table III of this rule are to be interpreted as follows: (i) A worker's exposure to any air contaminant listed in Table III, in any 8-hour work shift of a 40-hour work week, shall not exceed the 8-hour time weighted average limit given for that air contaminant in Table III. (ii) For respirable quartz of crystalline silica, the percentage of crystalline silica in the formula for mppcf or mg/m 3 is the amount determined from airborne samples, except in those instances in which other methods have been shown to the department's satisfaction to be applicable. (iii) For respirable quartz of crystalline silica, both concentration and percent quartz for the application of the limit of mg/m 3 are to be determined from the fraction passing a size-selector with the following characteristics in Table A. TABLE A Aerodynamics diameter (unit density sphere) Percent passing selector 2 90 2.5 75 3.5 50 5.0 25 10 0 (iv) For non-asbestos forms of talc for silicates, the mppcf threshold limit value is to be used where less than 1% quartz exists but if greater than 1% quartz exists, the quartz threshold limit value in Table III is to be used. (v) For all types of asbestos, the fibers per cubic centimeter level in Table III is to be determined by using the membrane filter method at 400 to 450 x (magnification) (4 millimeter objective) with phase contrast illumination. (vi) An mppcf measurement may be converted into million particles per cubic meter and particles per cc by multiplying it by a factor of 35.3. (d) The threshold limit values for air contaminants are listed in the following tables: TABLE I Air Contaminant ppm mg/m 3 Abate ........................................................................... 15 Acetaldehyde .............................................................. 200 360 Acetic acid ................................................................. 10 25 Acetic anhydride ........................................................ 5 20 Acetone ....................................................................... 1,000 2,400 Acetonitrile .................................................................. 40 70 Acetylene dichloride, see 1, 2-Dichloroethylene Acetylene tetrabromide ............................................ 1 14 Acrolein ....................................................................... 0.1 0.25 Acrylamide - Skin ...................................................... --- 0.3 Acrylonitrile - Skin ..................................................... 20 45 Aldrin - Skin ............................................................... --- 0.25 Allyl alcohol - Skin ..................................................... 2 5 Allyl chloride .............................................................. 1 3 C Allyl glycidyl ether (AGE) ..................................... 10 45 Allyl propyl disulfide ................................................. 2 12 2-Aminoethanol, see Ethanolamine 2-Aminopyridine ......................................................... 0.5 2 Ammonia ..................................................................... 50 35 Ammonium sulfamate (Ammate) ............................. --- 15 n-Amyl acetate .......................................................... 100 525 sec-Amyl acetate ...................................................... 125 650 Aniline - Skin .............................................................. 5 19 Anisidine (o.-p-isomers) - Skin ................................ --- 0.5 Antimony and compounds (as Sb) .......................... --- 0.5 ANTU (alpha naphthyl thiourea ................................ --- 0.3 Arsenic and compounds (as As) ............................. --- 0.5 Arsine .......................................................................... 0.05 0.2 Azinphos-methyl - Skin ............................................. --- 0.2 Barium (soluble compounds) ................................... --- 0.5 p-Benzoquinone, see Quinone Benzoyl peroxide ...................................................... --- 5 Benzyl chloride .......................................................... 1 5 Biphenyl, see Diphenyl Bisphenol A, see Diglycidyl ether Boron oxide ............................................................... --- 15 Boron tribromide ....................................................... 1 10 C Boron trifluoride ..................................................... 1 3 Bromine ...................................................................... 0.1 0.7 Bromine pentafluoride .............................................. 0.1 0.7 Bromoform - Skin ...................................................... 0.5 5 Butadiene (1, 3-butadiene) ....................................... 1,000 2,200 Air Contaminant ppm mg/m 3 Butanethiol, see Butyl mercaptan 2-Butanone .............................................. 200 590 2-Butoxy ethanol (Butyl Cellosolve) - Skin ............... 50 240 Butyl acetate (n-butyl acetate) ................................. 150 710 sec-Butyl acetate ...................................................... 200 950 tert-Butyl acetate ....................................................... 200 950 Butyl alcohol .............................................................. 100 300 sec-Butyl alcohol ....................................................... 150 450 tert-Butyl alcohol ........................................................ 100 300 C Butylamine - Skin ................................................. 5 15 C tert-Butyl chromate (as CrO 3 ) - Skin ................... --- 0.1 n-Butyl glycidyl ether (BGE) ..................................... 50 270 Butyl mercaptan ........................................................ 10 35 p-tert-Butyltoluene ...................................................... 10 60 Calcium arsenate ..................................................... --- 1 Calcium oxide ........................................................... --- 5 Camphor .................................................................... 2 --- Carbaryl (Sevin ® ) .................................................... --- 5 Carbon black ........................................................... --- 3.5 Carbon dioxide ....................................................... 5,000 9,000 Carbon monoxide ................................................... 50 55 Chlordane - Skin ...................................................... --- 0.5 Chlorinated camphene - Skin ................................. --- 0.5 Chlorinated diphenyl oxide ..................................... --- 0.5 Chlorine ..................................................................... 1 3 Chlorine dioxide ...................................................... 0.1 0.3 C Chlorine trifluoride ............................................... 0.1 0.4 C Chloroacetaldehyde ............................................ 1 3 a-Chloroacetophenone (phenacylchloride) ............ 0.05 0.3 Chlorobenzene (monochlorobenzene) .................... 75 350 o-Chlorobenzyliden malononitrile (OCBM) ............ 0.05 0.4 Chlorobromomethane .............................................. 200 1,050 2-Chloro-1.3-butadiene, see Chloroprene Chlorodiphenyl (42% Chlorine) - Skin ................... --- 1 Chlorodiphenyl (54% Chlorine) - Skin ................... --- 0.5 1-Chloro,2,3-epoxypropane, see Epichlorhydrin 2-Chloroethanol, see Ethylene chlorohydrin Chloroethylene, see Vinyl chloride C Chloroform (trichloromethane) ........................... 50 240 1-Chloro-1-nitropropane .......................................... 20 100 Chloropicrin ............................................................... 0.1 0.7 Chloroprene (2-chloro-1,3-butadiene) - Skin ........ 25 90 Air Contaminant ppm mg/m 3 Chromium, sol. chromic, chromous salts as Cr ............................................................. --- 0.5 Metal and insol. salts ........................................... --- 1 Coal tar pitch volatiles (benzene soluble fraction) anthracene, BaP, phenanthrene, acridine, chrysene, pyrene .................................. --- 0.2 Cobalt, metal fume and dust ................................... --- 0.1 Copper fume ............................................................ --- 0.1 Dusts and mists ................................................... --- 1 Cotton dust (raw) ..................................................... --- 1 Crag ® herbicide ..................................................... --- 15 Cresol (all isomers) - Skin ...................................... 5 22 Crotonaldehyde ..................................................... 2 6 Cumene - Skin ....................................................... 50 245 Cyanide (as CN) - Skin ........................................ --- 5 Cyanogen ............................................................... 10 20 Cyclohexane .......................................................... 300 1,050 Cyclohexanol ......................................................... 50 200 Cyclohexanone ...................................................... 50 200 Cyclohexene .......................................................... 300 1,015 Cyclopentadiene ................................................... 75 200 2,4-D ...................................................................... --- 10 DDT - Skin ............................................................ --- 1 DDVP, see Dichlorvos Decaborane - Skin .............................................. 0.05 0.3 Demeton ® - Skin .................................................. --- 0.1 Diacetone alcohol (4-hydroxy-4-methyl- 2-pentanone) ..................................................... 50 240 1,2-diaminoethane, see Ethylenediamine Diazomethane ....................................................... 0.2 0.4 Diborane ................................................................ 0.1 0.1 1,2-dibromoethane, see Ethylene dibromide, Table II Dibutyl phosphate ................................................. 1 5 Dibutylphthalate .................................................... --- 5 C Dichloroacetylene ............................................ 0.1 0.4 C o-Dichlorobenzene .......................................... 50 300 p-Dichlorobenzene .............................................. 75 450 Dichlorodifluoromethane .................................... 1,000 4,950 1,3-Dichloro-5,5-dimethyl hydantoin ................. --- 0.2 1,1-Dichloroethane ............................................. 100 400 1,2-Dichloroethane, see Ethylene dichloride, Table III Air Contaminant ppm mg/m 3 1,2-Dichloroethylene ........................................... 200 790 C Dichloroethyl ether - Skin .............................. 15 90 Dichloromethane, see Methylenechloride Dichloromonofluoromethane .............................. 1,000 4,200 C 1,1-Dichloro-1-nitroethane ............................ 10 60 1,2-Dichloropropane, see Propylenedichloride Dichlorotetrafluoroethane ................................... 1,000 7,000 Dichlorvos (DDVP) - Skin ................................ --- 1 Dieldrin - Skin .................................................... --- 0.25 Diethylamine ...................................................... 25 75 Diethylamino ethanol - Skin ............................. 10 50 C Diethylene triamine - Skin ............................. 10 42 Diethylether, see Ethyl ether Difluorodibromomethane ................................... 100 860 C Diglycidyl ether (DGE) .................................. 0.5 2.8 Dihydroxybenzene, see Hydroquinone Diisobutyl ketone ............................................... 50 290 Diisopropylamine - Skin .................................... 5 20 Dimethoxymethane, see Methylal Dimethyl acetamide - Skin .............................. 10 35 Dimethylamine .................................................... 10 18 Dimethylaminobenzene, see Xylidene Dimethylaniline (N-dimethylaniline) - Skin ...... 5 25 Dimethylbenzene, see Xylene Dimethyl 1,2-dibromo-2,2-dichloroethyl phosphate, (Dibrom) ..................................... --- 3 Dimethylformamide - Skin ............................... 10 30 2,6-Dimethylheptanone, see Diisobutyl ketone 1,1-Dimethylhydrazine - Skin .......................... 0.5 1 Dimethylphthalate ............................................. --- 5 Dimethylsulfate - Skin ...................................... 1 5 Dinitrobenzene (all isomers) - Skin ............... --- 1 Dinitro-o-cresol - Skin ..................................... --- 0.2 Dinitrotoluene - Skin ....................................... --- 1.5 Dioxane (Diethylene dioxide) - Skin ............. 100 360 Diphenyl ............................................................. 0.2 1 Diphenylmethane diisocyanate, see Methylene bisphenyl isocyanate (MDI) Dipropylene glycol methyl ether - Skin ........... 100 600 Di-sec, octyl phthalate (di-2-ethyl- hexylphthalate) ............................................... --- 5 Endosulfan (Thiodan ® ) .................................... --- 0.1 Endrin - Skin ...................................................... --- 0.1 Air Contaminant ppm mg/m 3 Epichlorhydrin - Skin ........................................ 5 19 EPN - Skin ....................................................... --- 0.5 1,2-Epoxypropane, see Propyleneoxide 2,3-Epoxy-1-propanol, see Glycidol Ethanethiol, see Ethylmercaptan Ethanolamine ..................................................... 3 6 2-Ethoxyethanol - Skin ..................................... 200 740 2-Ethoxyethylacetate (Cellosolve acetate) - Skin ................................................................. 100 540 Ethyl acetate .................................................... 400 1,400 Ethyl acrylate - Skin ........................................ 25 100 Ethyl alcohol (ethanol) .................................... 1,000 1,900 Ethylamine ..................................................... 10 18 Ethyl sec-amyl ketone (5-methyl-3-heptanone)... 25 130 Ethyl benzene .................................................. 100 435 Ethyl bromide .................................................. 200 890 Ethyl butyl ketone (3-Heptanone) ................. 50 230 Ethyl chloride ................................................... 1,000 2,600 Ethyl ether ........................................................ 400 1,200 Ethyl formate ................................................... 100 300 C Ethyl mercaptan .......................................... 10 25 Ethyl silicate .................................................... 100 850 Ethylene chlorohydrin - Skin .......................... 5 16 Ethylenediamine ............................................... 10 25 C Ethylene glycol dinitrate and/or Nitroglycerin - Skin ....................................... 0.2 1 Ethylene glycol monomethyl ether acetate, see Methyl cellosolve acetate Ethylene imine - Skin ...................................... 0.5 1 Ethylene oxide ................................................. 50 90 Ethylidine chloride, see 1,1-Dichloroethane N-Ethylmorpholine - Skin ................................ 20 94 Ferbam .............................................................. --- 15 Ferrovanadium dust ........................................ --- 1 Fluoride (as F) ................................................. --- 2.5 Fluorine ............................................................. 0.1 0.2 Fluorotrichloromethane .................................... 1,000 5,600 Formic acid ...................................................... 5 9 Furfural - Skin ................................................... 5 20 Furfuryl alcohol ................................................. 50 200 Glycidol (2,3-Epoxy-1-propanol) .................... 50 150 Glycol monoethyl ether, see 2-Ethoxyethanol Guthion ® , see Azinphosmethyl Air Contaminant ppm mg/m 3 Hafnium .............................................................. --- 0.5 Heptachlor - Skin .............................................. --- 0.5 Heptane (n-heptane) ........................................ 500 2,000 Hexachloroethane - Skin ................................. 1 10 Hexachloronaphthalene - Skin ........................ --- 0.2 Hexane (n-hexane) ........................................... 500 1,800 2-Hexanone ....................................................... 100 410 Hexone (Methyl isobutyl ketone) .................... 100 410 sec-Hexyl acetate ........................................... 50 300 Hydrazine - Skin ............................................. 1 1.3 Hydrogen bromide ......................................... 3 10 C Hydrogen chloride ...................................... 5 7 Hydrogen cyanide - Skin ............................... 10 11 Hydrogen fluoride ............................................ 3 2 Hydrogen peroxide (90%) .............................. 1 1.4 Hydrogen selenide ........................................... 0.05 0.2 Hydroquinone ................................................... --- 2 Indene ................................................................ 10 45 Indium and compounds, as In ......................... 0.1 C Iodine ............................................................ 0.1 1 Iron oxide fume ................................................ --- 10 Iron salts, soluble as Fe ................................... --- 1 Isoamyl acetate ............................................... 100 525 Isoamyl alcohol ................................................ 100 360 Isobutyl acetate ............................................... 150 700 Isobutyl alcohol ................................................ 100 300 Isophorone ........................................................ 25 140 Isoprophyl acetate ......................................... 250 950 Isoprophyl alcohol .......................................... 400 980 Isopropylamine .............................................. 5 12 Isopropylether ................................................ 500 2,100 Isopropyl glycidyl ether (IGE) ....................... 50 240 Ketene ............................................................. 0.5 0.9 Lead ................................................................ --- 0.15 Lead arsenate ............................................... --- 0.15 Lindane - Skin ............................................... --- 0.5 Lithium hydride .............................................. --- 0.025 L.P.G. (Liquified petroleum gas) .................. 1,000 1,800 Magnesium oxide fume ............................... --- 15 Malathion - Skin ........................................... --- 15 Maleic anhydride ........................................... 0.25 1 C Manganese ............................................... --- 5 Mesityl oxide ................................................. 25 100 Air Contaminant ppm mg/m 3 Methanethiol, see Methyl mercaptan Methoxychlor .................................................. --- 15 2-Methoxyethanol, see Methyl cellosolve Methyl acetate 200 610 Methyl acetylene (propyne) ........................... 1,000 1,650 Methyl acetylene-propadiene mixture (MAPP) ..... 1,000 1,800 Methyl acrylate - Skin .................................... 10 35 Methylal (dimethoxymethane) ....................... 1,000 3,100 Methyl alcohol (methanol) ............................. 200 260 Methylamine .................................................... 10 12 Methyl amyl alcohol, see Methyl isobutyl carbinol Methyl (n-amyl) ketone (2-Heptanone) ........ 100 465 C Methyl bromide - Skin ............................... 20 80 Methyl butyl ketone, see 2-Hexanone Methyl cellosolve - Skin ................................. 25 80 Methyl cellosolve acetate - Skin ................... 25 120 Methyl chloroform ........................................... 350 1,900 Methylcyclohexane .......................................... 500 2,000 Methylcyclohexanol ......................................... 100 470 o-Methylcyclohexanone - Skin ...................... 100 460 Methyl ethyl ketone (MEK) , see 2-Butanone Methyl formate ................................................. 100 250 Methyl iodide - Skin ....................................... 5 28 Methyl isoamyl ketone ................................... 100 475 Methyl isobutyl carbinol - Skin ...................... 25 100 Methyl isobutyl ketone, see Hexone Methyl isocyanate - Skin ................................ 0.02 0.05 C Methyl mercaptan ...................................... 10 20 Methyl methacrylate ....................................... 100 410 Methyl propyl ketone, see 2-Pentanone C a-Methyl styrene ........................................ 100 480 C Methylene bispenyl isocyanate (MDI) ....... 0.02 0.2 Molybdenum: Soluble compounds ........................................ --- 5 Insoluble compounds ...................................... --- 15 Monomethyl aniline - Skin ............................. 2 9 C Monomethyl hydrazine - Skin .................... 0.2 0.35 Morpholine - Skin ........................................... 20 70 Naphtha (coaltar) ............................................ 100 400 Naphthalene ..................................................... 10 50 Nickel carbonyl ................................................. 0.001 0.007 Nickel , metal and soluble cmpds, as Ni......... --- 1 Air Contaminant ppm mg/m3 Nicotine - Skin ...................................... --- 0.5 Nitric acid .............................................. 2 5 Nitric oxide ............................................ 25 30 p-Nitroaniline - Skin .............................. 1 6 Nitrobenzene - Skin ............................... 1 5 p-Nitrochlorobenzene - Skin ................ --- 1 Nitroethane ............................................. 100 310 Nitrogen dioxide ................................... 5 9 Nitrogen trifluoride ................................ 10 29 Nitroglycerin - Skin ............................... 0.2 2 Nitromethane ......................................... 100 250 1-Nitropropane ...................................... 25 90 2-Nitropropane ...................................... 25 90 Nitrotoluene - Skin ............................... 5 30 Nitrotrichloromethane, see Chloropicrin Octachloronaphthalene - Skin ............. --- 0.1 Octane .................................................... 500 2,350 Oil mist, mineral .................................... --- 5 Osmium tetroxide ................................. --- 0.002 Oxalic acid ............................................ --- 1 Oxygen difluoride .................................. 0.05 0.1 Ozone ..................................................... 0.1 0.2 Paraffin wax fume ................................. --- 0.2 Paraquat - Skin ..................................... --- 0.5 Parathion - Skin .................................... --- 0.1 Pentaborane ......................................... 0.005 0.01 Pentachloronaphthalene - Skin ........... --- 0.5 Pentachlorophenol - Skin .................... --- 0.5 Pentane ................................................. 1,000 2,950 2-Pentanone ......................................... 200 700 Perchloroethylene, see Tetrachloroethylene, Table III Perchloromethyl mercaptan ................ 0.1 0.8 Perchloryl fluoride ................................ 3 13.5 Petroleum distillates (naphtha) ........... 500 2,000 Phenol - Skin ....................................... 5 19 p-Phenylene diamine - Skin ............... --- 0.1 Phenyl ether (vapor) ............................ 1 7 Phenyl ether-biphenyl mixture (vapor) ... 1 7 Phenylethylene, see Styrene Phenyl glycidyl ether (PGE) ................ 10 60 Phenylhydrazine - Skin ......................... 5 22 Phosdrin (Mevinphos ® ) - Skin .......... --- 0.1 Air Contaminant ppm mg/m 3 Phosgene (carbonyl chloride) ............. 0.1 0.4 Phosphine .............................................. 0.3 0.4 Phosphoric acid ................................... --- 1 Phosphorus (yellow) ............................. --- 0.1 Phosphorus pentachloride .................. --- 1 Phosphorus pentasulfide ..................... --- 1 Phosphorus trichloride ......................... 0.5 3 Phthalic anhydride ................................ 2 12 Picric acid - Skin .................................. --- 0.1 Pival ® (2-Pivalyl-1,3-indandione) ...... --- 0.1 Platinum (Soluble salts) as Pt ............ --- 0.002 Propargyl alcohol - Skin ....................... 1 --- Propane .................................................. 1,000 1,800 n-Propyl acetate ..................................... 200 840 Propyl alcohol ......................................... 200 500 n-Propyl nitrate ....................................... 25 110 Propylene dichloride .............................. 75 350 Propylene imine - Skin ........................... 2 5 Propylene oxide ...................................... 100 240 Propyne, see Methylacetylene Pyrethrum ............................................... --- 5 Pyridine .................................................. 5 15 Quinone .................................................. 0.1 0.4 RDX - Skin ............................................. --- 1.5 Rhodium, Metal fume and dusts, as Rh .. --- 0.1 Soluble salts .......................................... --- 0.001 Ronnel .................................................... --- 10 Rotenone (commercial) ........................ --- 5 Selenium compounds (as Se) ............. --- 0.2 Selenium hexafluoride ........................... 0.05 0.4 Silver, metal and soluble compounds .. --- 0.01 Sodium fluoroacetate (1080) - Skin ..... --- 0.05 Sodium hydroxide ................................. --- 2 Stibine ..................................................... 0.1 0.5 Stoddard solvent ................................... 500 2,950 Strychnine ............................................... --- 0.15 Sulfur dioxide ......................................... 5 13 Sulfur hexafluoride .................................. 1,000 6,000 Sulfuric acid ........................................... --- 1 Sulfur monochloride .............................. 1 6 Sulfur pentafluoride ................................ 0.025 0.25 Sulfuryl fluoride ...................................... 5 20 Systox, see Demeton ® Air Contaminant ppm mg/m 3 2,4,5-T .................................................... --- 10 Tantalum ................................................ --- 5 TEDP - Skin ........................................... --- 0.2 Tellurium .................................................. --- 0.1 Tellurium hexafluoride ............................ 0.02 0.2 TEPP - Skin .......................................... --- 0.05 C Terphenyls .......................................... 1 9 1,1,1,2-Tetrachloro-2,2-difluoroethane ......... 500 4,170 1,1,2,2-Tetrachloro-1,2-difluoroethane ......... 500 4,170 1,1,2,2-Tetrachloroethane - Skin ......... 5 35 Tetrachloromethane, see Carbon tetrachloride Tetrachloronaphthalene - Skin ............. --- 2 Tetraethyl lead (as Pb) - Skin .............. --- 0.075 Tetrahydrofuran ...................................... 200 590 Tetramethyl lead (as Pb) - Skin ........... --- 0.075 Tetramethyl succinonitrile - Skin ........... 0.5 3 Tetranitromethane .................................. 1 8 Tetryl (2,4,6-trinitrophenyl- methylnitramine) - Skin ......................... --- 1.5 Thallium (soluble compounds) - Skin as T1 ......... --- 0.1 Thiram ...................................................... --- 5 Tin (inorganic compds, except oxides) .... --- 2 Tin (organic compounds) ...................... --- 0.1 C Toluene-2,4-diisocyanate .................. 0.02 0.14 o-Toluidine - Skin ................................... 5 22 Toxaphene, see Chlorinated camphene Tributyl phosphate .................................. --- 5 1,1,1-Trichloroethane, see Methyl chloroform 1,1,2-Trichloroethane - Skin .................. 10 45 Titanium dioxide ..................................... --- 15 Trichloromethane, see Chloroform Trichloronaphthalene - Skin .................... --- 5 1,2,3-Trichloropropane ........................... 50 300 1,1,2-Trichloro 1,2,2-trifluoroethane ...... 1,000 7,600 Triethylamine ............................................ 25 100 Trifluoromonobromomethane ................. 1,000 6,100 Trimethyl benzene ................................... 25 120 2,4,6-Trinitrophenol, see Picric acid 2,4,6-Trinitrophenylmethylnitramine, see Tetryl Trinitrotoluene - Skin ............................... --- 1.5 Triorthocresyl phosphate ........................ --- 0.1 Triphenyl phosphate ................................ --- 3 Air Contaminant ppm mg/m 3 Tungsten and compounds, as W Soluble .. --- 1 Insoluble .................................................... --- 5 Turpentine .................................................. 100 560 Uranium (soluble compounds) ................ --- 0.05 Uranium (insoluble compounds) ............. --- 0.25 C Vanadium: V 2 O 5 dust ................................................... --- 0.5 V 2 O 5 fume .................................................. --- 0.1 Vinyl benzene, see Styrene Vinylcyanide, see Acrylonitrile Vinyl toluene ............................................... 100 480 Warfarin ....................................................... --- 0.1 Wood dust .................................................. --- 5 Xylene (xylol) .............................................. 100 435 Xylidine - Skin ............................................ 5 25 Yttrium .......................................................... --- 1 Zinc chloride fume ..................................... --- 1 Zinc oxide fume .......................................... --- 5 Zirconium compounds (as Zr) .................. --- 5 TABLE II A ir Contaminant 8-hour time weighted average Acceptable ceiling concentration Acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift Concentration Maximum duration Benzene 10 ppm 25 ppm 50 ppm 10 minutes Beryllium and beryllium compounds 2 m g/m 3 5 m g/m 3 25 m g/m 3 30 minutes Cadmium dust 0.2 mg/m 3 0.6 mg/m 3 Cadmium fume 0.1 mg/m 3 0.3 mg/m 3 Carbon disulfide 20 ppm 30 ppm 100 ppm 30 minutes Carbon tetrachloride 10 ppm 25 ppm 200 ppm 5 minutes in any 4 hours Chromic acid and chromates 0.1 mg/m 3 Ethylene dibromide 20 ppm 30 ppm 50 ppm 5 minutes Ethylene dichloride 50 ppm 100 ppm 200 ppm 5 minutes in any 3 hours Formaldehyde 3 ppm 5 ppm 10 ppm 30 minutes Hydrogen sulfide 10 ppm 20 ppm 50 ppm 10 minutes once only if no other measureable exposure occurs Mercury 0.1 mg/m 3 Mercury, organo (alkyl) 0.01 mg/m 3 0.04 mg/m 3 Methyl chloride 100 ppm 200 ppm 300 ppm 5 minutes in any 3 hours Methylene chloride 500 ppm 1,000 ppm 2,000 ppm 5 minutes in any 2 hours Styrene 100 ppm 200 ppm 600 ppm 5 minutes in any 3 hours Tetrachloro-ethylene 100 ppm 200 ppm 300 ppm 5 minutes in any 3 hours Toluene 200 ppm 300 ppm 500 ppm 10 minutes Trichloroethylene 100 ppm 200 ppm 300 ppm 5 minutes in any 2 hours TABLE III - MINERAL DUSTS Air Contaminant Millions of particles per cubic foot of air (mppcf) e Milligrams per cubic meter (mg/m 3 ) Silica: Crystalline: Quartz (respirable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 %SiO 2 + 5 10 mg/m 3 % SiO 2 + 2 Quartz (total dust) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mg/m 3 % S 2 O 2 + 2 Cristobalite: Use 1/2 the value calculated from the count or mass formulae for quartz. Tridymite: Use 1/2 the value calculated from the formulae for quartz. Amorphous, including natural diatomaceous earth . . . . . . . . . . . . . . . . . . . . . . . . . 20 80 mg/m 3 % SiO 2 Silicates (less than 1% crystalline silica) : Mica. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 20 Soapstone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Talc (non-asbestos form) . . . . . . . . . . . . . . . . . . . . . . 20 Talc (fibrous) . Use asbestos limit. Tremolite (see talc, fibrous) Portland cement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Graphite (natural) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Coal dust (respirable fraction less than 5% SiO 2 ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 mg/m 3 or For more than 5% SiO 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mg/m 3 % SiO 2 + 2 Inert or Nuisance Dust: Respirable fraction . . . . . . . . . . . . . . . . . . . . . . . . . . .. . Total dust . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . 15 50 5 mg/m 3 15 mg/m 3 Fibers per cubic centimeters (f/cm 3 ) Asbestos (all types) (asbestos fibers = asbestos fibers longer than 5 micrometers) . . . . . . . . . . . . . . . . . . . . . . . 2