Document 1028wqdOqk3ga4XxkvbYoOO3X

AMERICAN sly by * vuh A-nt tavc uca.1 tad n. if c Yo/ume 17 ScPTM8R, 1956 Number 3 Symposium os Threshold Limits Present Trends in MAC's............................................................................ .W'n, rrn A. ''""k The Need for Threshold Limit*................. -................................... .\/irin,,t S'trlt*. Prepared Discussion.................................................................................. Umr>j y. Suf/ih. Jr. Methods of Kstablishini; Threshold Limits...........................-/! //. Sh-rnrr. MJ>. Prepared Discussion............................. ................................... llrrhrrt K. Shiwixm-r. I'tt.ll. Engineering and Chemical Application of Standards......... Mini />. lhlimit. Sr.!). Prepared Discussion ........................................................................................... \,iUnr f\ Shin Prepared Discussion ............................................................... Tlu-txlurr ('. ll'rtr.x. I.!..!!. d7*5 *7-1 ^Ti) :jxo US i tiDti Automatic Instrumentation mi; Air Pm.j.i'Tins Mi>nit-*iu.\i;---a I'mMttjv.cs Report un Automatic Directional Aik Sampling................. ir,7/../, ,l .'/....... . A Versatile I'oktarle Aik Sampler...........................!L S. Jouhtn ./ U. .X. Miirim'l ::u:: Determination ok Internally Deposited Radioactive Isotope* from Excretion Analyses...............^..............................................MAhjJit !!. /.<*<,/,,,, ::u" Criteria for an Evaluation ok N*ui*e It.uslems..........r/m*7r* /.*. Wiii'm,,,*. i-u.P. Flow Calibration ok Hhih-Volu.mk Sampler* ..................................................................... Ur rim ril !). Trhlmtx, Sr.I)., am! Dumtitl ,)!. A </o. M.S. ::iij i'U7 Recent Industrial Hycjkne DevEL>t*MENT>i--a Svmi***s11 m In the Field of Air Pvllution.........................................................................../)..,/< tUtli In the Field <j( Chemistry ................................................................. A'/W,./. Smith. I'h./i. in the Field of Kmcincerintf.................................. ....................... /..AY ,n'<7. . Sr.J/. In the Field of Xoise......................................................................... .............. I//. //<// In the Field of Radiation.................................................................................... S---I j. fin,,'* in the Field <j( To.xiculu^y ................................................ //-// // K. .V/iA/>>/< , , I'lt.lK UIU ::y.y. ll.'Pi :;;:y '1411 HrciENir cuipk series ................................................................................................................... "4f President's pao>: ............................................................................................................................. Selected Titixs and arstr.mts ....................................................................................................... Hook Review ................................................................................................................................................ ::."4 AJHA I.MlCSTnjAL ASSOCIATES, OKKtC'KKs. DlKElTi.iC.'. A.\o Com \,j !TK .................... `SA, IsousTKIa*. tfTOIKKC ASSUCIATni* *iTrtl.i, i>vl.l>Oi*U Ur u> Amrfiean linJui>lfll !<?* A- yoeintian in Xkfeti, Jun*. StoitTnbnr. nil QnrmMr. Jtn* > N. iin.t, >:-nt<ir: Kiamr J 'Vm**, .*,iuory EJiwo LiAu K. .Owuir Kiiiinrt Wiij.iam S, \.ivi-ftixiiv Kilix" I'm i, t< 'I ujj.i. r.r- Iiiaum EdtLor: A. 0. CU/OO. ?uoUftr; [v-tw Fi.nussur, EUitwcim Aivtuni. n*I EJiwrirJ Q<- Ma, 0i Non* Micflivaa Avtnut. Oilutii 11. illino*. .'glMrinoun JA.ini in-r >'vsr in ihe CmU-j sii: 14.SO >*r r**r in CadaUa: IJ.UO rar in oV\*r (tuntrm. .mikI> . vim-i. < I On- Jhi* i'iur IA 12.'JQ. Cwu> <'et\L tSSri, \fi* A MLXk'a.'i i > ousTiu At. HMiit*.*. uriH.' Miit--i -.inil eiaA mti* \r Rr J. 194>. at U> sert gille as ShruwrKnn. iin* Vt Mgi*n I'Tv. THr `.^txiCAS ISOlisYWAl, HlCitNC Aa^sAlATlitN QeArsJU.T Iftr f'u'hl to .-.ill Ml vlKrUurnwiil. gml w ia* 009^ rh*n A 4.^9 nw n.rrt in (iicn prulnxonti iun>ltril< .U.-vU-O uy \--Aigiiun. i S f i t i 3 f c  r. ' s Symposium on Threshold Limits Present Trends in MAC's introduction by WARRSN A. CCOK. Associate Professor Industrial Health and Hygiene, School of Public h'eaith University of Michigan. Ann Arbor THE TH1NX1NC today on the concept of threshold limits of injurious materials, limits and the improper us** of them. No where is the present concept of threshold designated by whatever term, has passedlimits more ;ibly and competently expressed through an evolution to a gratifying ,.m- than in the paj>ers and discussions of this tnrity. Symposium. Initially the need to know how little of a That the discussants might not have Iht; toxic substance might remain in an indus very Iasi word, it may he permissible for trial atmosphere without injur}' to those ex this prologue to assume in part the preroga posed was insistently apparent. Such in tive of an epilogue! The following com formation began to be supplied through cor mentaries appear pertinent. relation of concentrations of injurious sub The best publication of the American stances with observed effect on the health Standards Association Z-'l7 Committee on n{ the worker for such materials as granite Maximum Acceptable Concentrations of dust' and lead compounds.- Results of short Toxic Ousts ami Cases'1 is ripMirtcd cor time animal experiments had been svailabfe rectly as 1JJ41J by Sachs who deplored the even before the present century from such lack of revision nf the 10-41 Standard for c investigator? aa K. B. Lehmann* and later benzene at the obsolete level of 100 parts from Yant and others at the U. S. Bureau per million. It is tn he noted that this ASA of Mines,* with the classic combined long- Committee is now active in the revision and exposure animal experimentation and oc publication of MAC Standards for many cupational study on benzene by Greenburg* of the materials on which information is in the middle twenties. available. As these threshold limit values became The term `'maximum acceptable concen more numerous and were more widely ap trations" was adopted by the ASA Commit plied. it is perhaps not surprising that mis tee for a number of reasons. The word "as. conceptions and aberrant usages occurred. ceptable" does not connote the legal control Some persons erred in considering the levels inherent in the words "allowable" and "lim more precise than the facts justified: others it." but rather a simple acceptability with rejected them because the values could not out further implication. Also, the expres precisely fit ail conditions of exposure and sion. .MAC. has been widely used over the physiological response. And the detractors years and is now a part >>f the language, in were for a while more vociferous and seemed fact the Germans adopted a wording whicn possibly to be more sound than the pro gives the abbreviation. MAK. so that this tagonists. . . term may be used in international conversa '.Vith rime, there has been a separation of tion. Their words as used in the title of a the valuable advantages of the threshold paper by OetteC are "Maximal** Arbeits- piatz-Konzentratinn." It is understood that K ift* Jnini Smimii of Ui* AHRirtK Is. Hfr.:*-** a vctir** r*n-***:or nr Oo*n**e.-TAt IrXH.'STStAI. H YC1K* i.-TT* H Ifw 10&& l(\. lujinai Health Conference. Butf*Jo. April ZS. 1364. this same expression is thirty used in the "MAK" tables of the Gorman Association for Worker Protection. rs September, 13-S4 r% However, there van he no really vniid ob known cnncerigenicity of arsenic, chromates c:e- it. jection to '.he term "Threshold Limits'* used and asbestos. Says Oettel "In this 1 see a w;: S |r by the 1'iimmitice of the American CnnferI'licf i>f (Invcmmunlal industrial Hygienists nf to "Hygienic Guides," the term adopted great dancer. The lists should in any event remain logical.** Waters' discussion of Brandt's paper oc asjl.il ijy the American industrial Hygiene Asso cupies the final paces of this publication of ho\- ciation committee. This .Symjxisium wnuid the Symposium, but it is believed that w:: ant be complete without reference to the Waters would not wish his comments to be M:: availability of the excellent AIHA Hygienic considered the last word on the subject of Guides to which reference is marie else threshold limits--rather that his observa he; where in this .Journal. tions are limited essentially to the use of lev- 2/ ; One nf the most perplexing problems in these values in lecal codes, rigidly fixed by wo arriving at threshold limits is posed by the statute. As the last word in this Symposium, du cancerigens. Stokinger's statement in this this introductory refers the render to the Symposium is the first publication on this conclmiinc paragraphs of the paper by cn f phase of the subject. However, the use of Brandt for his discussion of the philosophy tic the procedure suggested by Slokioggr as ap of threshold limits. ntr plied to nickel carbonyl has already drawn some (in*, Quoting in part from a private communication from (Jcttel whose publica tions"* on "MAhl's" include a well-cimsidcred presentation of the general subject: "We soggest that consideration be jsiven to References I. Rl'>aA A. K,. IlKITTTN. R. H-. L, JC. I'.:.,-* * J. J.; Tl.,* Heflin n( iVortu, in Ouxit (l. f.M'miir. S>lic"*<c Oiui iCmmw Industry!. /oft/iV II,.ill* Util. N.,. IT. 132?. 1. ki'oj. a. k.. a. a.. ni^^nr.Lj. j. j_ II!TTt?i. a. H,, Tnnr-i*. L. R-: da Ud tb cr indicating th* suspected cancerigens with Sin,.** Italtrrw IMs.nl. /<--- Mull. St. S>i. I9:i3. (- an asterisk with reference to a footnote that .1. [,tn ,m a.x.v, K. I*.: in ,1 fir /or Ht,i<rr t ram ih* l**0*4. Oi the hazard exists and consequently especial 4. V1.1t. W. P,, nd eolku*i: Atit Rnfionw of ly effective control measures be instituted. No man can say today which concentration Uuin*n i'ie* lo Vi**r oi Six** Corftrnre>*l Or- (nir Ci>n>i>ourKl. A nf 3o*r tiypli< i<v Public Hrnllh Rf rtnnnc in* >93rt'. j of.the several industrial substances is actu j. GuCRSai'xC. L.: R*nxol Porxomn* an Indu*. A 94'. ally required to be eanccrigenic . . .'* This statement follows his objection to the pres mi Hu,rrt. Hr*ith rf'iut^ 41. 1.147. UlO. and 111?: 13-S. *. Am*ricn Slandam* A<oeiation: Stnnam3a an Ac* -te- *4 ent listing by the ACGIH uf nickel car rvotaM* Ci>nf"tiio"t n( Toxic Ousu and *,un. ASA. bonyl as U.Onl ppm on the basis of its al ?n ^ ;5ih Sin-i. Y<* 17. 7. 0*nTtt H-; 0>* maximal* ArnmLiOixix.Uonxxntra- leged cancen gcnicUy, which incidentally li.*n .MAX* AVn < .anailian** (tax*. DameV* unit Oettcl's extensive experience with the sub stance causes him to doubt, while faiiing SLauO*. ti>r /Irrtfmnr--pm^.meAAft, St. 2. Foru*rr. 1954. x. Orrrrx. H.; <U>w*rhlitn* V*rri/tun<n durn 0***. Oamofr un>l Slaulmnrn. ,lrrAp l.r Tanroidf,*. 15:41. to include any acknowledgement of the 1954. ' * The Need for Threshold Limits a., iviiRiAM SaCHS. m.D. Ne- jcr'.ev Stete OecerTmer.t oi Health. Bureau of Adult ana Occupational Health Trenton. Ne^ jersey 3. P?* 5" ftoium.r one of the most basic needs in purpose as a ; uint of aim for individual human endeavor is for man to have an interpretation. If this seems cryptic, an ex n nrrieriimtss set tn his manner of thinkinc. ample cnncernnic a common substance may Everyone has a need for discipline, for be cited. < f boundaries to be drawn, and for limits to be A!mo>c everyone is familiar with the , defined. It docs not matter that the nniy use threshold limit values for silica--for dust > ' .. \\ for .'omo of the limits >u defined muv be tn with a free silicon dioxide content above ienure them; they have still served their jOr(. the limit is given as five million parti- r ,