Document gEDn6G7QkpORNDezKb38LwLJG

PUBLICHEALTH REPORTS -~ VOL. 43 JULY 23, 1929 KO. 23 BEXZOL F'OISOSIKG-4s A POSSIBLE H-4ZABD IN CHEMICAL LXBORATORXES e By 3. J. BLOOUFXE,LasDsi.slanl P b ~ s i c oCl hemist, 0 p c c of Industrial Hygiene and Soidation, Cnitcd Slofcs Public Heoith Serrice The hazard a t t e ~ d i n gthe use of benzol in industrp has been well es;ahliehed by the recent studks conducted by the Vnited States Public Henlth Service in cooperation with the Sational Safety Council.' .is a result, of these studies it was concluded that "The me of benzol (except in inclosed rncchanical s)-stems), cscn r h e n :he x-cjrkcrs sre protected by the most complete and e8ectiTe s y s t e m of eshnust \-entilntion, keeping the arerage concentration of benzol in the ~wr1;rooriiair below 100 parts per million, inrolws a substantial hnzsrd. E\-sry possible effort should, therefore, be made to dewiop the use of s h t i t u t e sol-rents of a less toxic nature ivherever this is possible. `' Quite rccmtly the writer's attention has bcen called to the fact t h a t benzol is iised to R considerable estent in chemical laboratories. This is cspecisily tilie in those laboratories where tests are conducted in connection with rubbx. paint, n r n i s h , and oil products. Such tests usually in-iolre tbe determination of the soluhilicy of compounds in \-RI+OUS solrcnts such as benzol, carbon disulfide, and scetone. x\-crol SW!I lnboratory workrooms were recently iui-estigatcd by thc Ti-ritcr \s-jrii the purpose of determining trhethcr or not the use of benzol in these :r-orl;roonis const itutcd asource of 21health. In these laboratories from 3 to 5 gdlons of benzol -mre used i\-eelilplnininiy in the cstraction of f u d oils and in certain solubility determinations. In certain tests the procedure called for centrifuging with benzol the matcrid to be tested, B practice eroliing considernble benzol -n p o r in the 2ir. Air analyses made in three 1nbwatory rooms where benzol was being used showed a concentration of n p o r Tarring froin 3 parts per ndIion in cne room to 223 parts per million in another. In the latter rooin two centrifuges were used iatermittently in tho manner jusr described. Besides using benzol for e.xperimenta1 purposes it was obserred that this solvent IRIS also cmplo_red in ciesning apparatus nnd in mshing the hsnds and arms free from stain$. This practice is quite - i J July 20.1923 1896 common, since many of the materids tested contain asphalt, con1 tar, and rnmishes, substances difficult to remove from g k s w r e and the skin miih ordinary cleansing ngents. It is quite obvious that such practice on the part of chemists tends to add to the aniount of benzol rapor in the laboratory air and should be abolished., Eren though the use of benzol for esperimental purposes may be justified in certain instances, c e r t d d y by some less tosic solvent., s w h as ~ 1 0 1 ,should be substituted for use in cleaning apparatus and lis a skin wash. In one laboratory room as much as 3 gallons of beiizcl per week was used .zs n cleansing agent. As stated earlier, the study of benzol poisoning in industry disclosed the fact that the e-sposure to benzol rapor of concentrations ePen ns IOiT as 100 parts per million inrolres 3 substantial hazard. Conditions in chcxnicsl laboratories M e r from those in industry in that the use of benzol is u s u d y intermittent. So that i t does not seem prxtical to apply the standards of rapor conceutrntions evolred for industrial establishments to those laboratories not using benzol constantly throughout the irorliday. -4 better criterion for e d u a t i n g the estent of benzol poisoning is a blood e s a h n t i o n of the worker e:iposed, since the most characteristic pathologicti effect of beiizol is its dectructire influence upon the cells of the blocd and the blood-foriiiing organs. In chronic benlzol poisoaiug the whiteblood cell count is reduced to a considerable estent. Hence, in attenipting to fisa standard for the white-cell count which xoilld, along with a liisrory of eqosure. be indicative of benzol pois~ni?g, the in~estigstorsof Cnited Stntes Pubiic Health Sen-ice decided that a fnU in the c o u t below 3,600 per cubic millimeier might be acci-ptcd as rcssonnblp clear eridence of the conciition in question. Chronic benzol poisoning produces aIso a marked change in the relstionship betn-em the tarious t-pes of white-blood ceils present. In benzol poisoning the percentnge of ITmphoqte ceiIs is re!ativeiy increased and that of the polpiorphonuclear lcucocj-tes is meriredy decreased. In m s h g a disposis of benzol poisoning these aspects of the diEcrentia1 count must be carefully considered. Blood emminations of the workers esposed to benzol rapor in the chemical laboratories Tisited by the writer did not shorn an abnormal is-hite-blood cell count. Hon-ewr, the blood of three of the men showed a departure in the relationship between the Tarious trpes of lvhite-blood cells. Suc!i n blood picture, coupied with a d c h itc exposure to scjlwnt rapors of R ccncentrstion considered toxic, accordbig to present-day stenderds, teiids to indicate that the possibility of benzol poisoning in chemical laboratories must be sonsidered. b.iany industrial plant the cost of suitable c chemical laboratories u sidered as a potential ha to justify its retention ( call? all chelnicd labor solvent k n o m to beless It is recommended at chemical laboratories testing of niaterials on1 agent. Also, in order d i e n its effects can be benzol fumes should be employment., and ree? evxy month or two t on reesaminatiou, sh (obtained froin a prey! froin benzol esposure. '.:I ! * e 1 *.) :, t il L n i .-I. .It 0 . *.. .... . ,(. i r . . .....I....../...:......; ..... !,I I , *.';.';~;-.-!f. !! . .. .. . . . . . . . . . . . r*11!3111 . . .. ,!hf.l,?l ..... .,*.,r I,. 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