Document NeEpvyLYOLGwMVGvMGdpZekYR

Jl. ces in these categories and for which no speci fic threshold limits have been assigned. This limit, for a normal work day, does not apply to brief exposures at higher concentrations. Neither does it apply to those sidtstances which may cause physiologic impairment at lower concen trations but for which a threshold limit has not yet been adopted. Some "inert" particulates are given in Appendix D. Simple Asphyxiants-**Inert** Gases or Vapors. A number of gases and vapors, when present in high concentrations in air, act primarily as sim ple asphyxiants without other significant phys iologic effects. A TLV may not be recommend ed for each simple asphyxiant because the limit ing factor is the available oxygen. The minimal oxygen content should be 18 percent by volume under normal atmospheric pressure (equivalent to a partial pressure, pO2, of 135 mm Hg). Atmos pheres deficient in Oz do not provide adequate warning and most simple asphyxiants are odor less. Several simple asphyxiants are listed in Appendix E. Some asphyxiants present an ex plosion hazard. Account should be taken of this factor in limiting the concentration of the asphyx iant. These limits are intended for use in the field of industrial hygiene and should be interpreted and applied only by persons trained in this field. They are not intended for use. or for modifica tion for use, (1) as a relative index of toxicity, by making a ratio of two limits, (2) In the evalu ation or control of community air pollution or air pollution nuisances, (3) in estimating the toxic potential of continuous uninterrupted exposures, (4) as proof or disproof of an existing disease or physical condition, or (S) for adoption by coun tries whose working conditions differ from those in the U.S. Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ioniz ing radiation, humidity, abnormal pressure and the like may place added stress on the body so that the effects from exposure at a threshold limit may be altered. Most of these stresses act adversely to increase the toxic response of a substance. Although most threshold limits have built-in safety factors to guard against adverse effects of moderate deviations from normal en vironments, the safety factors of most substan ces are not of such a magnitude as to take care of gross deviations. For example, continuous work at temperatures above 9PF or over-time, extending the work-week more than 507,, might be considered gross deviations. In such instan ces judgment must be exercised in the proper adjustments of the threshold limit values. These values are reviewed annually by the Committee on Threshold Limits for revision or additions, as further information becomes avail able. "Notice of Intent'* At the beginning of each year, proposed actions of the Committee for the forthcoming year are issued in the form of a "Notice of Intent." This Notice provides not only an opportunity for comment, but solicits suggestions of substances to be added to the list. The suggestions should be accompanied by substantiating evidence for a tentative limit. As Legislative Code. The Conference does not consider the Threshold Limit Values appro priate matter for adoption in legislative codes and regulations and recommends against such use. If, however, the list is so used,the intent of the concepts contained in the Preface should be maintained and provisions should be made to keep the list current. Reprint Permission. This publication may be reprinted provided that written permission is ob tained from the Secretary-Treasurer of the Con ference and that it be published in its entirety. RECOMMENDED VALUES (In Alphabetical Order) Stikatanca 0P* Acetaldehyde........................................ Acetic acid ................................................. Acetic anhydride......... .. . Acetone....................................................... Acetonitrile................................................ Acetylene dichloride, see 1,2 Didomethylene .................................................. Acetylene tetrabiomide............................. Acrolein.................................................. Acrylonitrile-Skin.............. AldrinSktn................................................. Altyl alcohol-Skin ........... ............ Allyl chloride.............................................. C Allyl gtycidyl ether (AGE)............... Ally! propyl disulfide..... 2 Aminoethanol, see Ethanolamme . . Ammonia .................................................... Ammonium sulfamate (Animate)................ s-Amyl acetate......................................... Aniline-Skin ................................................ + Anisidine (o,p<isomeis)~Skin.................... Antimony & compounds (as Sb)............... ANTU (alpha naphthyl thiourea) . . Arsenic & Compounds (as As)... .. Arsine......................................................... Barium (soluble compounds)............... C Benzene (benzol)-Skin .. . Benzidine-Skin.......................................... p-Benzoquinone, see Quinone................. + Benzoyl perostde........................................ Benzyl chloride................................... Beryllium.............................................. t Biphenyl, see Diphenyl............................ Boron oxide ........................................... C Boron bifluetide......................................... Bromine.................................................. Butadiene (1.3-tutadiene)........................ Butanethiol, see Butyl mercaptan ............ 2-Butanane................................................... 2-Butoxy ethanol (Butyl Cellosolve)-Skin t Butyl acetate (n-fautyi acetate) . Butyl alcohol............................................ tert. Butyl alcohol ..................................... C Butylaraina-Skin................................... C te>L Butyl chromate (as Cr03|-Skin n-Butyt gtycidyl ether (BGE)................ Butyl mercaptan.............................. 200 10 5 1.000 40 360 25 20 2. 400 70 i 01 20 - 2 1 10 2 14 0.25 45 0 25 5 3 45 12 so 35 - IS 100 525 S 19 - 0.5 - OS - 0.3 - 0.5 0.05 0.2 - 0.5 25 80 - A1 -5 15 - 0.002 - 15 13 0.1 0. 7 1.000 2. 200 200 S90 50 240 -- 100 300 100 300 5 IS - 0.1 SO 270 10 35 * tali *1 vopar h ga> Pr million part, ol !, pl,, mpn, br rolomn nr JS*C and 760 mm. Hg pniun. " Approximate milligrams ot particulate po, cubic malar af atr. A Mvwhom. Son Appandio A t 1966 Addition | See Tentative Limits 03122222