Document 7mMpQKpKoYxryav6Vdm1vpvR

I Threshold Limit Values For 1964 Adopted at the 26th Annual Meeting of the American Conference of Governmental Indus trial Hygienists, Philadelphia, Pennsylvania, April 25 - 28, 1964 LAM02 7605 B0C3213 6113 18462 Svbitonc* ppm Mo/kt*** t Yttrium............................................ Zinc oxide fume............................ Ziiconium compounds (as Zr).... - 5 5 Radioactivity: for permissible concentrations of rsdio-isotooes m air. see U. S. Department of Commerce. National Bureau of Standards. Handbook 69. "Maximum Permissible Body Burdens and Manmum Permissible Concentrations of Radi* onwciides in Air and m water for Occupational Exposure,'' iune S. 1959. Also, see U. $. Department of Commerce National Bureau of Standards. Handbook 59. "Permissible Dose from External Sources of ionizing Radiation," September 24. 1954. and addendum of April 15. 19SS. * Parts of vapor or gas per million parts of air by volume at 25*C and 760 mm. Hg pressure. Approximate milligrams of particular per cubic meter of air. A Numbers. See Appendix A 11964 Revision see Tentative Values MINERAL OUSTS Substioce m.p.p.c.f.* SILICA Crystalline Quartz, Threshold limit calculated 250 ** from the formula.................................. %SiO*+ 5 Cristobalite " Amorphous, includin( natural diatomaceous earth ........................................ SILICATES (less than 1% crystalline silica) Asbestos .... ................................ -........ ...... Mica ...................--_____ _______________ Soapstone ................................. Talc ......................................................... Portland Cement _______________ 20 5 20 20 50 "Inert'' or Nuisance Particulates 50 (or 15 mg/m 3 whichever is the smaller) 20 Curversici (actors mppcf s 35.3 -- million particles per cubic meter = particles per c.c. Millions of porliclts por cubic foot of otr. based on impinger uinploo counted Oy lifftMitld technics. Ttie porcontaao of crysteilloe mice In the formulo Is the mount determined tram air-borne semplet. oicopt In tftoso instoncot In which other methods hove bdon shown to bo appticoblo. f 14 TENTATIVE VALUES Substance ppm" Mp/M'** ++Anisidine (o. p-isomets)............ H-Benzoyl petoxide........................... Calcium oxide............................... r+Catbatyl (Sevin) (R).................... Coppei Fume................................. Dusts (.Mists........................... n-Cotton Dust (iaw)........................ H-Cyclopentadiene........................... 75 Demeton (Systox) (R).................. H-l, 3 - Dichloto-S, 5-dimethyl hydantoin................................... r+Oimethyl 1, 2-dibromo-2, 2- dichloioethyl phosphate, iDibioml (R) ........................... H-Oimethylamme................................ 10 + Oimethylformamide Skin ........ 10 i-i-Oi sec. octyl phthalate (Di-2- ethylhexyl-phthalate)............... - Epichlothydtin................................ 5 Ethanolamine.................................. 3 Giaphite.......................................... - Hafnium........................................... - t+Hexachloroethane - Skin.............. 1 t-Hydrogen Sulfide............................ 10 t-t-L. P. G. (Low pressute gas) (Liquid petroleum gas)............. 1,000 r+Maleic anhydnde............................ - ++Methane.............................................1.000 r+Methyl acetylene-piopadtene moituie, IMAPP) .....................1,000 Methyiamine.................................... 25 + Methyl meicaptan........................... 10 Methyl methaaylate 100 C Methylene bis phenylisocyanate 0.02 Minerat wool, fibrous glass........ - ++MonomethyI hydrazine - Skin...... 0.2 ++Morpholine - Skin............................ 20 0.5 5 5 5 0.1 1.0 1 200 0.1 0.2 3 18 30 5 19 E ISmppcf 0.5 9.7 15 g 31 20 410 0.2 2 Q3S 70 ' Ports of vapor, or coo por million parts pf air by volume ot ZS*C oae ZW mm. He pressure. * Approximate mllliframs of porticuloto por cubic meter o< oil. *1144 Roviolon. ** 1904 AMlHans. BCC3214 15