Document X89wBypGYYg6L2REy3g86VzDy

ELEMENTS OF INDUSTRIAL TOXICOLOGY TABLE 40-B THRESHOLD LIMIT VALUES FOR 1983 (Continued) Appendix B (Continued) IB. (continued) Tm = 700 X g 1 = 155 ppm Solution applicable to "spot" solvent mix ture usage, where all or nearly all, solvent evaporates. 2 A mixture of one part of (1) parathion (TLV, 0 1) and two parts of (2) EPN (TLV, 05) Cl . Ci 01 05 Cm C. = 2Ci Ci =3Cl Cl _2Ct_ 01 + 05 7Ci _ 3Ci 3Ci Tm 05 ' T, 15 Tm = 7 = 0 21 mg/m' b. General exact solubon for mix tures of n components with addi tive effects and different vapor pressures c. c. (1) "tT + "tT + ` -5*-------i + To ' (2) G + C + . - + Cd = T. (21) Co * T~ By the Law of Partial Pressures, (3) Ci = apt. And by Raouh's Law, (4) pi -- F*Pi. Combine (3) and (4) to obtain (5) Ci = aFipi Combining (1), (21) , and (5), we obtain (6) FiPi8 --j , + Ftp*0 t"+ , f=e1= 1- T . F,p, . T, + T. +* + T, . and solving for T, _ FiPi* -f FPa" + 10 i; "Fjel . is* . T, ^ T, + FoPn" Fopn T. (62) or T = 2 Fip7r I--i T, where T = Threshold limit value in ppm. C = Vapor concentration in ppm p = Vapor pressure of compo nent m solution p = Vapor pressure of pure com ponent F = Mol fraction of component in solution a = A constant of proportionality Subscripts 1,2, n relate the above quantities to components 1A . . n, respectively Subscript i refers to an arbitrary component from 1 to n Absence of subscript relates the quantity to the mixture Solution to be apphed when there is a reservoir of the solvent mixture whose composition does not change appreciably by evaporation. c Exact Arithmetic Solubon of Specific Mixture Mol wt Density T Mol fracbon m p at half-and 25 C half solu bon by volume Trichloro ethylene (1) 1314 1 48 g/ml 100 73mm Hr 0527 Methylchloroform (2) 133 42 1 33 g/ml 350 125mm Hr 0 473 F,pi = (0527)(73) = 382 Fip = (0 473)(125) = 59 2 _ 38 2 -f 59 2 _ (87 4 H 350) _ 1 " 38 2 + 592_ ~ 133 8 + 59 2 ~ 100 350 (97 4 X 350) _ nnm 193 0 ~ 177 pp (Note difference m TLV when account is taken of vapor pressure and mol fracbon m comparison with IB a 1 where such account is not taken) 1C INDEPENDENT EFFECTS 1. From naphtha (TLV, 500) con taining 10 mole per cent benzene (TLV, 25) the narcobc effects can be considered as approximate- Lthe same as that of benzene naphtha. The blood effects can be consid- 40-10