Document RnbQjQrmEQ542dBy39x1VkLX

^7 /S'} INTERNAL CORRESPONDENCE 7^' From PITTSBURGH MEDICAL DEPARTMENT Re: INDUSTRIAL HYGIENE To R. S. Adams C. G. Bell Cjf HAiruTs) ll -Or Ole an Cleveland * " * 1`. D. Conosa -fj&KfiS - Edggeewwatai ter W. G. Dotson Badin B. H. Droz Wenatchee G. J. Fickes Vancouver ASK. obbs Cressona. XisS'Hl. uoa F. Kramer M. A. Uarr - Buffalo R. H. Moore - Rosiclare J. J. Moroney - Massena <s - R. E. Paine Pracht ---J. T. Quirk - Vernon Diivanpcrti-- - Bridgeport R. C. Roberts - E. St. Louis J. V/. Schachtele - Chillicothe R. E. Schenk - Detroit H. A. Semken - Rockdale D. F. Shantz - Richmond C* S* Short - N.K. C. L. Teubert - Chicago E. M. Trimble - Bauxite Mining W.V.M .Williams - Alcoa Smelting R. G. Wood - Lafayette E. B. Youngblut - Lancaster Attached are the following items which should be of considerable interest: 1. A.C.G.I.H. Threshold Limit Values, 1955. 2. Information on aluminized cloth for protection against radiant heat. 3. Hazardous exposure to so-called safe solvents. U. Letter from Mr. J. T. Hobbs re Controlled Atmosphere Generating Units. LVC/db cc: Dr. D. A. Irwin Mr. C. L. Bradshaw Mr. T. Bonney Lester V. Cralley \ r ail] -4 ftf APC 001309 THRESHOLD LIMIT VALUES FOR 1955 Adopted of the Seventeenth Annoel Meeting of the Americon Conference of Governmental Industrial Hygienists, Buffalo, April 24*21, 1955 ~\7 A l-UES arc given in the following tabulation for the maximum average atmos^ pheric concentration of contaminants to which workers may be exposed for an eight-hour working day without injury to health. These values are based on the best available information from industrial experi ence, from experimental studies, and, when possible, from a combination of the two. They are not fixed values but are reviewed annually by the Committee on Threshold Limits for changes, revisions, or additions as further information becomes available. Threshold limits should be used as guides in the control of health hazards and should not be regarded as fine lines between safe and dangerous concentrations. They represent conditions only within which it is felt that workers may be repeatedly exposed, day after day, without their health being adversely affected. It is felt, at the present time, that workers should not be exposed to a working environment containing any of these substances in excess of the value indicated. These values are not intended for use, or for modification for use, in the evalua- tion or control of community air pollution or air pollution nuisances. - ESTABLISHED VALUES CASES AND VAPOftS l`|ISTAN*Cr. PPM* SUBSTANCE PPM' Acetaldehvde...................................... . 200 Acetic acid.......................................... 10 Carbon dioxide ................................. . 5.000 Carbon disulfide ............................... 20 Acetic anhvdnde .............................. 5 Acetone................................................ . 1.000 Acrolein .............................................. 0.5 Acrylonitrile ...................................... 20 Ammonia ............................................ 100 Amyl acetate...................................... . 200 Amyl alcohol (isoamyl alcohol).. 100 Carbon monoxide............................. Carbon tetraehloride....................... Cellosolve (2-ethoxyethanoI) .... . Cellosolve acetate (hydroxyethyl acetate) .......................................... . Chlorine .............................................. Chlorobenzene (monochloro* 100 25 200 100 1 Aniline ................................................ 5 benzene) .......................................... 75 Arsine ................................................... 0.05 Chloroform (trichloromethane) . . 100 Benzene (benzol) ............................ . 35 l-Chloro*l-nitropropane................. 20 Bromine .............................................. 1 Chloroprene (2-chlorobutadiene) . 25 Butadiene (l.J-butadiene) ........... 1.000 Cresol (all isomers) ....................... 5 Butanone (methyl ethyl ketone).. . 250 Cyclohexane ..................................... . 400 Butyl acetate (n-hutyl acetate).. . 200 Cyclohexano]..................................... . 100 Butyl alcohol (n-butanol)............. 100 Cyclohexanone ................................. . 100 Butyl cellosolve (2-butoxyethanol) 200 Cydohexene ..................................... . 400 * o( vapor or nt |*r imllton pari* il ait. by vi lltlltiv. 521 APC 001310 SUBSTANCE TPM* Cyclopropane..................................... 400 0-Dichlorobenzene ........................... 50 Dichlorodiftuoromethane ................ 1,000 1.1- Dichloroethane....................... 100 1.2- Dichloroethylene .................... 200 Dichlorocthyl ether.......................... 15 Dichloromonofluoromethane .......... 1,000 1,1-Dichloro-l-nitroethane.............. 10 Dichlorotetrafluoroethane .............. 1,000 Diethylamine............................. .... 25 Dimcthylaniline (N-dimethyl- aniltne) ......................................... 5 Dimethylsulfate ............................... 1 Dioxane (diethylene dioxide)........ 100 Ethyl acetate..................................... 400 Ethyl alcohol (ethanol).................. 1,000 Ethylamine ....................................... 25 Ethyl benzene ................................... 200 Ethyl bromide................................... 200 Ethyl chloride .. ............................... 1,000 Ethyl ether ....................................... 400 Ethyl formate................................... 100 Ethyl silicate ................................... 100 Ethylene chlorohydrin .................... 5 Ethylene dibromide (1,2-dibro- moethane) ..................................... 25 Ethylene diehloride (1,2-dichloroethane) ........................................... 100 Ethylene oxide................................. 100 Fluorine ............................................. 0.1 Fluorotrichloromethane .................. 1,000 Formaldehyde............................. 5 Gasoline ............................................. 500 Heptane (n-heptane) ...................... 500 Hexane (n-hexane) ....................... 500 Hexanone (methyl butyl ketone).. 100 Hexone (methyl isobutyl ketone).. 100 Hydrogen chloride.................... 5 Hydrogen cyanide ........................... 10 Hydrogen fluoride........................... 3 Hydrogen selenide........................... 0.05 Hydrogen sulfide ............................. 20 Iodine .............................. ................. 1 Isophorone......................................... 25 Mesityl oxide ................................... 50 Methyl acetate ................................. 200 Methyl alcohol (methanol)............ 200 Methyl bromide ............................... 20 Methyl cellosolve (methoxyethanol) ......................................... 25 522 INDUSTRIAL HEALTH SUBSTANCE PPM* Methyl cellosolve acetate (ethylene glycol monomethyl ether acetate) ............................... 25 Methyl chloride ............................... 100 Methyla! (dimethoxymethane) ... 1,000 Methyl chloroform (1,1,1- trichloroethane) ........................... S00 Methylcydohexane ........... 500 Methylcyclohexanol.......................... 100 Methylcydohexanone ...................... 100 Methyl formate ............................... 100 Methylene chloride (dichloro- methane) ....................................... 500 Naphtha (coal tar) ....................... 200 Naphtha (petroleum) .................... 500 Nickd carbonyl................................. 0.001 Nitrobenzene..................................... 1 Nitroethane ....................................... 100 Nitrogen dioxide ............................. 5 Nitroglycerin..................................... 0.5 Nitromethane ................................... 100 2-Nitropropane................................. 50 Nitrotoluene ..................................... 5 Octane ............................................... 500 Ozone ................................................ 0.1 Pentane............................................... 1,000 Pemanone (methyl propyl ketone) 200 Perchlorethylene (tetrachloro- ethylene) ....................................... 200 Phenol ............................................... 5 Phosgene (carbonyl chloride)........ 1 Phosphine........................................... 0.05 Phosphorus trichloride.................... 0.5 Propyl acetate ................................. 200 Propyl alcohol (isopropyl alcohol) 400 Propyl ether (isopropyl ether).... 500 Propylene diehloride (1,2-dichloro- propane) ....................................... 75 Stibine..................................................... 0.1 Stoddard solvent ............................. Styrene monomer (phenyl ethylene)........................................ S00 200 Sulfur monochloride....................... 1 Sulfur dioxide................................... 10 1,1,2,2-Tetrachloroethane ................ 5 Toluene............................................... 200 o-Toluidine ....................................... 5 Trichloroethylene............................. 200 Turpentine ......................................... 100 Vinyl chloride (chloroethene)........ 500 Xylene................................................. 200 APC 001311 THRESHOLD LIMIT VALUES TOXIC DUSTS, FUMES, AND MISTS SUBSTANCE mc. rat CU. IC.f Antimony ................................................ 0.5 Arsenic................................... ................. 0.5 Barium (soluble compounds)................ 0.5 Cadmium................................................. 0.1 Chlorodiphenyl........................................ 1 Chromic acid and chromates as CrOa.. 0.1 Cyanide as CN........................................ 5 Dinitrotoluene.......................................... Dinitro-o-cresol...................................... Fluoride .................................................. 1.5 92 2.5 Iron oxide fume...................................... 15 Lead......................................................... 0.15 Magnesium oxide fume........................... 15 Manganese ................................ ............ 6 Mercury .................................................. 0.1 Parathion (0,0-Diethyl-0-nitrophenyl thiophosphate) .............. 0.1 Pentachloronaphthalene.......................... 0.5 Pentachlorophenol................................... 0.5 Phosphorus (yellow) ........................... 0.1 Phosphorus penfachloride...................... 1 Phosphorus pentasulfide........................ 1 SUBSTANCE mc. ru CU. M.f Selenium compounds (as Se)............... 0.1 Sulfuric acid.............................................. I Tellurium ............................................... 0.1 Tetryl (2,4,6-trinitrophenyl- methylnitraminc)................................ 1.5 Trichloronaphthalene............................ 5 Trinitrotoluene.............'.......................... 1.5 Uranium (soluble compounds)............ 0.05 Uranium (insoluble compounds).......... 0.25 Zinc oxide fumes..................................... 15 Radioactivity: For permissible concentrations of radioisotopes in air see "Maximum Permissible Amounts of Radioisotopes in the Human Body and Maximum Permissible Concen trations in Air and Water,M Hand book 52, U. S. Department of Com merce, National Bureau of Standards, March, 1953. In addition, see "Per missible Dose from External Sources of Ionising Radiation/' Handbook 59, Department of Commerce, National Bureau of Standards, Sept. 24, 1954. + Millirruni of dust, fume, or mitt per cubic meter of air. MINERAL DUSTS SUBSTANCE MFPCFt Alundum (aluminum oxide)...................... 50 Asbestos ....................................................... 5 Carborundum (silicon carbide).................. 50 Dust (nuisance, no free silica).................. 50 Mica (below 5% free silica)........................ 20 Portland cement ......................................... 50 Talc..................................................................20 SUBSTANCE MPFCft Silica high (above 50% free SiOi)................. 5 medium (5 to 50% free SiOi)............... 20 low (below 5% free SiOt)..................... 50 Slate (below 5% free SiOi).................... 50 Soapstone (below 5% free SiO)............ 20 Total dust (below 5% free SiOi)............... 50 t Million! of particle* per cubic foot of air. TENTATIVE THRESHOLD LIMIT VALUES The following values are suggested for further consideration before being presented for adoption as established values. ( marks materials added this year and for which bibliographic material has been prepared. The other materials appeared in last year's report.) It is proposed that the entire list will be presented for adoption at the meeting of the American Conference of Governmental Industrial Hygienists in 1956, if no reason to the contrary is forthcoming. Aidrto 044.4,10.1'bxaeh1oro-1.4.4a,S3.8*hexabydrol14.6.S-dlmetbaDODephihalOc) Allyl alcohol ...................................... *................................................................................................... Allyl propyl dlaulflde............................................................................................................................. Ammete lammootuto amidoaullate)............................................................................................. Beezyl chloride ....................................................................................................................................... f Butyl amloc ............................................................................................................................................. Butyl mercaptao .................................................................................................................................. Calcium araeoate................................................................................................................................... Cblordaoe 0.i.4A3.733-oetaebloro.Sa.4.7.7atetrahy(iro-4.7.methaoomd*ne>.............. 1 Chlorine tnfluortde ............................................................................................................................. I Chlorinated dipbeoyl oxide................................................................................................................ Crac Herbicide (*d1uro-2.4.dlchloropbeoo*y ethyl sulfate)............................................. 0.26 mr/u* 6 ppm 2 ppm IS mr/M 1 ppm 6 ppm 10 ppm os mr/M* 2.0 melM1 0.1 ppm o.s mf/M* 16 ror/M1 523 INDUSTRIAL HEALTH 2,4>D(2,4-dicbloropbeaoxyaetle neld) .................................................................... D. D. T. <L2bL-(*-ebloropbenyl>*U4*trtcblorlbao) .................................... Diaeatona nteobol (4*b7drox7<4-mtbyl panisouoe-2)......................................... | DibornM.............................................................................................. ........................ [HeldrId (l,2J,(,l040bxacbloro4.?, poxy].4,4a,5.6.7.Ma-octaby<lrol,4,M dimctbtnooapbthntena) ..................................................................................... I Dffluorodlbromomeibans ....................................................................................... Dtlaobutyl ketoos ...................................................................................................... EPN (cthybp-nltropbeoyl Uilooo benxeae pbospboattc).................................. Ethyl tnercnptnn ...................................................................................................... S Elhyieua diamine....................................................................................................... I Ethyko# Ic&lna.......................................................................................................... Ferro vanadium dust................................................................................................ Furfural ...................................................................................................................... I Furfuryl alcohol ....................................................................................................... I Hydraxfna................................................................................................................... Uydrocea bromide ................................................................................................... Hydroveo peroxide, 90%.......................................................................................... iUydroQoloooe ........................................................................................................... UopropyUmtoe ......................................................................................................... iLead araeoate ......................................................................................... *................ Uodaue (bexacblorocycluhexaoe, famine uuiucr)........................................... Malatbon (O.CHJlmstbyl dUbio pboipbeta of dieuayl uiereapiosucclflate).. Meiboxychlor (iXdtparametboxypbenyl-l.l.l.uichioroetbans) .................... I Methyl acetylene ...................................................................................................... Methyl laobutyl earblnol (methyl amyl aleobol).............................................. Methyl mercaptan..................................................................................................... Molybdenum I (soluble compounds) ........................................................................................ f (insoluble compounds)................. .........................-....................... .............. y-NItroaniline ............................................................................................................. Orfaoo aereurlals (as mereury)........................................................................... Percbioromethyl mercaptan .................................................................................. Phenylhydrazlne ...................................................................................................... Plerte add ................................................................................................................. S Propylene Mntne ............................................................................. ,...................... Pyridine .................................................................................................................... I Quinone...................................................................................................................... Sodium hydroxide................................................................................................... fluliur hexafluoride ................................................................................................. Sulfur peataduoride ............................................................................................... TEDP (tetraethyl dltbiuoo pyropbospbate)................................................... TEPP (tetraethyl pyropbospbate)...................................................................... I a-Tertiary butyl tolucoc......................................................................................... I Tetrabydroluran ..................................................................................................... I Tetraultrometbane ................................................................................................. Titanium dioxide ................................................................................................... I Trifluuromonobrotnometbsne ............................................................................. Vanadium (V*Oe dust) ....................................................................................................... (VsOs tuuie) ...................................................................................................... I Zlrtooliiiu .................................................................................................................. 10 inr/M' 1.0 mg/M* 60 ppm 0.1 ppm 0.25 IDf/M` 100 ppra 60 pptn 0.5 wg/M* 250 ppm 10 ppih 6 ppm 1 mt/M* 6 ppm too ppm 1 ppm 5 ppm 1 ppm 2 mg/M* i pptn 0.1 mg/M* 04 mg/M* 15 mg/M* 15 mg/M* .1,000 ppm 25 ppm 60 ppm 6 mg/M* 16 mg/M* 1 ppm 0.01 mg/M* 0.1 ppm 6 ppm 0.1 mg/M* . 25 ppm 10 ppm ppm mg/M* ppiu 0.025 ppm mg/M* > mg/M* ppm ppm ppm mg/M* ppm 0.6 mg/M* o.i mg/M* 6 mf/Ma Beryllium: During the past few yrais, several papers bavc appeared in the literature which report a limit ef 2y per culuc meter of air fur beryllium. Aiming these is the paper by Vau Ordstrand. H. S.: Berylliosis, A. hi. A. Arch. Imdust. Hyg. 10:222*234 (Sept.) I9$4, and one by Sterner. J. H.. and Eiscnbud. M.: Eptdeauolugy of Beryllium Intoxication, A. hi. A. Arck. 1 adust. Hyg. 4:12J*1S1 (Aug) 1951. Conflicting data from industrial experience bat caused tbe Committee to postpone the suggestion of a Threshold Limit for this material. It is apparent that more cpidcmiologie work is needed for tbe establishment of a denmte value. Reference material has been prepared on each of the above substances and, though in some instances rather meager, is available for distribution. The committee would welcome suggestions of substances to be added and also comments, additional references, or reports of experience with these materials. William L. Ball L. T. Faiahall Kingsley Kay H. E. Stokinger A. J. Vorwald Louis F. Weller Allan L. Coleman, Chairman Re: ALUMINIZED CLOTH We have had the occasion to study an aluminized cloth produced by the Minnesota Mining and Manufacturing Company. The coating is produced by a new process in which most of the original properties of the cloth are maintained. Yfe have been impressed by the material and believe that the aluminized duck made into aprons and sleeves can be an effective shield for radiant heat. 3-M was contacted for a list of protective clothing fabricators who use their material. The following companies were givens Wheeler Protective Apparel, Inc. 221* West Huron Street Chicago 10, Illinois Mine Safety Appliances 201 N. Braddock Avenue Pittsburgh 8, Pa. Industrial Gloves Co. Danville, Illinois Industrial Safety Specialties Co., Inc. Eighth II Chestnut Streets Perkasie, Pennsylvania Safety Clothing & Equipment Co. 1090 E. 69th Street Cleveland 3, Ohio American Optical Southbridge, Mass. Literature has been received from the above companies and while all market face shields and aluminized asbestos, only the Safety Clothing i Equipment Co. and the Mine Safety Appliances furnish clothing made from aluminized duck. It is suggested that those with radiant heat problems consider the use of the above material. L. V. C. APC 001314 IM SO-CALLED IAFE SOLVENTS--HUGHES Beecher11 alio found the difference between placebo and morphine more atrikirvg with 3% carbon dioxide inhalutkm than with inhalation of room air. A partiul explana tion for this fact ii that the deprenion of the retpiratory center U manifested ftrtt by a decrease in Its reserve, ns measured by its ability to respond maximally to the driv ing force of an increased pressure of carbon dioxide in the arterial blood. A second factor of importance, demon strated by Loeschcke and associates ' is the increase in alveolar and arterial pressure of carbon dioxide that oc curs after a dose of morphine. This acts in a compensa tory fashion by increasing the stimulus to the respiratory center and thus masking the effect of the drug in patients breathing room air. A third possibility comes to mind, however. Ordinary respiration is subject to a certain amount of voluntary control. The greater variability in retpiratory rate and minute volume between subjects when breathing room air than between the tame subjects breathing 3% carbon dioxide " suggests that the use of a powerful involuntary retpiratory stimulus may override voluntary factors and thus reduce the variance due to nondntg factors. Because of simplicity of measurement, it is customary la many laboratories to report respiratory minute volume in such studies, although effective alveolar ventilation k actually the Information desired. The use of respiratory minute volume rather than effective alveolar ventilation eosma partially justified by the failure to find significant (hinges in respiratory rate after administration of mor phine in the doses used. Although this lends support to J.A.M.A.. fepl- is. IVM the use of this parameter ax n valid index of rcspiiutory depression, the technique may lead l> un underestimation of the depressant effects of morphine. If the dead space does not change significantly, the per cenl decrement in effective ulvcnlar ventilation would he even greater than the decrement in respiratory minute volume, since the percentage of this volume contributed by dead space would be greater after administration of morphine titan ufter administration of a placebo. SUMMARY AND rONrt.USIONS A study of puin relief in 122 pulients after operation revealed only slight increase in potency and duration of analgesia of morphine when the dose was ruined from 10 to 15 mg. The side-action liability and respiratory effects of these two doses were studied in 10 healthy vol unteers. In this latter group, a trend wus observed toward greater respiratory depression with the larger dose, and a significantly higher incidence of troublesome sideeffects was recorded. A review of the literature indicates that 13 mg. doses of morphine are probubly unnecessary to relieve pain in the majority of patients receiving this drug and are apparently more productive of undesiruble side-effects than 8 to 10 mg. doses. In view of these findings the routine use of 15 mg. seems unwarranted. The optimal dose appeurs to be 10 mg. per 70 kg. of body weight. IT Knit. A. I.. tnd Beecher. H. K.: Afiallc Pmeiss. ead Suit Action LlaMtHp ta Mtfi Ol WIN *-Mrihyl UiftyUio- morphine. Mttopon, Lffro-laomrlhMiooc ont) Pcnuthartollat SataJiunv jv a Further Eflon to Refine Mclhoik of Evaluation n( Analgeak Drum. J. Pharmacol. A Eapcr. Iherap. ltl&i 109 (Jonci 1952 HAZARDOUS EXPOSURE TO SOME SO-CALLED SAFE SOLVENTS James P. Hughes, M.D., Cincinnati There is scarcely an industrial plant or a business that .'does not use some solvents. The kinds and the quantities vary from the can of type cleaner in the secretary's desk to tank car loads of leu familiar substances used as de greasing agents in the metal trades or as vehicles in the manufacture of chemicals. There are hazards in the han dling of all solvents because of their appreciable volatility. Some danger may be recognized by the user, but flam mability and explosiveness are more likely to be consid ered than physiological action. The selection of a solvent for a specific purpose de pends on technological factors, such as required action, volatility, handling practice (including vapor recovery), the tendency of the substance to leave a residual film on metil surfaces, cost, and availability. The safety aspect may be introduced as a last consideration but, perhaps, only in terms of risk of fire or explosion. The final choice usually is a compromise. While none of the criteria for aelectkm can be ignored, only rarely is it possible to meet all of the demands made. The purchasing agent may suggett a low cost petroleum distillate, the fire chief mjy . . : * Keuerlei Laboratory. Department of Prevrnil*, MtJicln oy_l0Mrtol_H.IUi. Depanmem of laiermel Medicine. Uimef.liOool Oool Oh Ilia Actual Meeting of Attottodto. CMcaoo. April it. IPM. she American Industrial Hyglrne want carbon tetrachloride, and the safety engineer may propose a new preparation of dubious composition labeled "Safety Solvent--Nontoxic." No one will be completely satisfied, and the industrial hygiene adviser may be least satisfied of all. A situation threatening to health now may arise. One solvent may he accepted with out question as being "safe" from the point.of view of toxicity and then handled quite carelessly; another, rec ognized as being relatively toxic and requiring some control measures may be inadequately controlled. Trouble can occur in either of these situations as sug gested by some recently observed episodes. PULMONARY EDEMA CAUSED HY lXI'OSUKI tu METHYLENE CTILOHIDI. Case I.--A Negro mute laborer, uged IV. w.i, admuicst to Cincinnati General Hospital because of shortness of bre.iih. cough, and suhsicrnal pain uf eight boms' duralion. On his lust day of employment in a meial parts assembly shop, he h.id been given the |Ob of degreasing small copper gaskcis b> dipping them into an open drum of methylene chloudc He slated ih.ti the .olvem bulb ''fell like ice water" on his bare hands. He had .maning of the eye. on bending over the drum, and he noie.l an opprc.ivc odor. The work area was fuund 10 he in a sni.ill. dark, brick garage. There wa> no eshausi ventilation or mechanical equipment of any kind for the movement of uir. During the taller part of the ihifi this boy complained of excessive f.iiiguc. weak ness. sleepiness, hghtheadcdne.s. chilly sensations, and nausea. ARC 001315 \ ol. I5h, Nm. y NO-CALLED NAFF. NOLVEVI-HUCHE lit IU tiiMtu .iiu i .1 iiti.tl i< lour liottr* of woik. He fell asleep I'lM .out on .ikittK mo hours luicr fell very weuk. short of hu-.iih. .ol h.ul . dry. nonproductive tough. He hud Mtbsiernul p.un on viMiylunj; ;ind deep breathing. On .idmusioii to Ihe hospit.il hu icmperuiure was MX) F. piil^c t.iie MHi. .nd lespii.oory rule 42. Iherc wu> mild respiratory duoes K.ilcs were lie.ud ul the husc of ihe right lung und oce.*- sion.illy elsewhere over ihe ehcsi. On u rocnigenogrum of Ihe ehesi tlieie w.is ilillu\c. fu//y mliluulion disinhutcd hilutcrully ihiouglutui hoih lung lields. characteristic of pulmonary cdcm.i uee iigmei I heie w.is no eonjuneiiviiis or irriiution of the akin. Ihe p-iiiem treated with HKI.(HX) units nf penicillin intfu* muss'tdaiM eve> eight hours htu did noi require ihe adminisim- lion ol ovygen Within 12 hours ufier admission und IX hour* ulier ihe Iasi e\posuie. there wus mtul relief of sympioms; the tctnpciatuie. pulse rate, and respiratory rule were normal. Faint iiupiiaioiy and expiratory rales were still heurd at the base of hoih lungs, hut these had disappeared a few hours later. The lesulis ol complete blood cell count, urinulysu, blood culture, and blood urea nitrogen determination remained normal. Chest toenigenogriims made after intervals of thice and live days were noimal. and the patient was then discharged from the hospital. MctlisIcnc chloride, also called dichloromethunc. has conic inio increasing industrial use us a paint remover, refrigerant, and. less extensively, as a degreas ing solvent. It has a pronounced narcotic action, but it is more irritating to the respiratory system and more csciiiiiors than is chloroform.1 In industrial use only slight acute cllccts had been reported until 1952 when Mnskov.it/ and Shapiro reported the clinical histories of four men exposed to a high concentration of methylene chloride vapor in a plant where un olenresin was ex tracted from vegetable material.- There was loss of con* sciousncss in all of those exposed, with one immediate death and some irritation of the upper respiratory truct ol short duration in the others. Methylene chloride had been described by Browning as "practically harmless" in ordinary use.' When the local vendor of ihe solvent was advised of the illness of the hoy referred to ahovc he staled vigorously that some other solvent must have been used, since methylene chloride is so "safe." As a matter of fact, this was found to he the only volatile substance in the shop. The sug gested minimum tolerable concentration of methylene chloride under conditions of regular industrial employ ment is 5titi ppm. Nevertheless, it should he recognized that this solvent is capable of acting as a pronounced K-'i'ii.ilois irritant. Ihe probability of some absorption ol the solvent tluough ihe skin, in addition to the inhala tion ol vapoi. must tv considered as a contributing factor in tins ease. I lie lialogenated hydrocarbons arc excreted cluclly through the lung', regardless ol the mode of ab sorption. Pulmonary irritation may occur as a result ol the exaction. well as die absorption, of these sub- stances. aii it til I1 v 111 is i in i ms isi. t \rost to hi II I K VI III I1HIII i m i t si 1 -si y -- \ while m.ile r*-w\tr-iIJ -ale- trainee of a cheniieat .onipanv wa. ailmme.l 10 a lui-pti.il in another en> in April. 1*1*1. hee.ooe of i.iitmliee. weakness, anU anoresi.i. the onecl of sviiipi.tms h.nl oeeiuteil |u ilavs earlier, with nausea, vomiting, -tail none. Ii^ihi hrown stools, an.l vleepenmp jaunjiec. bor sis momhs prior 10 ihe onsei of svmptonts he hail worked on main tenance an.l repair nf solvent cireiitahng ss-tem- in dty cleaning e.i.iHohmenis. boi a penoj of 11 weels op to the umc that he became ill he had worked rcgularl> on telrachlorocth) lenc unite Mic j.h duties inelcided the rehlling of eceiemc wuh cnlvcnl. mechanical repairs, and test running of units. When emergency repuirs were necessary he often worked 12 to 16 hour ihlfu and sometimes over week ends without regular days off. Expoaurg to the solvent, both as liquid and vapor averaged over eight hours per day. When lines were repaired some of the solvent drainod out onto the floor. The servicemen often worked near these spills. I he cleaning plants usually ssrere hot, humid, and poorly vend* luted. No gloves or other personal protective equipment were used. On one occasion this man had spilled a pall of tetrachloroethylene over his shirt and trousers. He noted burning and tingling sensation of ihe akin until he changed hit garments several hours later. On iwo or three occasions he became light headed when the concentration of vapor teemed especially heavy hut returned lo work after a short period In fresh air. The odor of tcirachlorocihylcne became Increasingly distasteful to him during this period. For two weeks before the onset of lllatti there was excessive fatigue and unusual difficulty In rising in the morning. Hncmpcmwam of the chi of min aipoaad to mathylana chloride (case I). I he medical history was not significant except (Hit ihe pelient hud received one intramuscular injection of penicillin in the treutment of a brief episode of nausea and vomiting on Feb. 7, 1V5.V Ml weeks prior to the onset of this Illness. He rarely drunk uny type of alcoholic beverage and never to the point of intoxication. On admission to the hospital he wat Jaundiced. The results obtained from tests of liver function were grossly abnor* mul and suggestive of hepatocellular dysfunction. He made an uneventful recovery, but when he was examined four weeks luicr there was still some evidence of Impaired liver function. 1 he results of hemogram and urinalysis were within normal limits. He wus removed from work on systems designed for the use of chlorinutcd hydrocarbon solvents but continued in the Job of sulcs und maintenance work on other types of solvent units. I en months after the acute illness, he reported thet on one or t. Hrowntn*. E.: Tottclty of Industrial Oriantc loteaau, Na Ywk l hrmual Puhitehini Company. Inc.. Jt9). 2 Mmsnwtt/. and Shapiro. H-: Fatal lapoaura id MaftqlaM l htortde Vapor. A M A. Arch IMutl. Hys* Si III (Aap.) 1911. s 1 hrrwhoid Limit Values for 1fS4. Adorned at tM Moashis 1 *a Amcruan ConltreiKc ot Governmental Induemat HyfWniaca. ChSaooo. 1*54. A M. A Arch Induet. Hu 000 liana) ItU. APC 001316 2.U MMAI.ITI) *AKK MIIAKNTH^m c.llKS two occasions whe he hud worked briefly near m tciTiichloio* ethylene system he hud experienced nausea immediately on de tecting ihc hum odor of ihe solvent. Tetr;ichlim>clh>lcnc. CO-iC'Cl.. uImi culled pereltlorcthyicnc. ix usuully placed lowcxi in toxicity in the asccndinj; series of chlorinated hydrocarbons used as dr> cleaning agents ' Until recently no unchallenged cases of toxic cllccts front its industrial use had heen reported. Colcr und Kossmiller huve now presented some clinical observations as hemp suggestive of impairment of liver function in three men of u group of seven engaged part lime in the degreasing of small steel disks in u lank con taining tcirachlorocthylenc.' Complaints of headache, nausea, lighthcadcdncss. fuliguc. stuggering gait, and mcntul confusion were said to have been common among these men. Concentrations of tctruchlorocihylcnc in the utmosphcrc of the workrttom were reported to average front 2.12 to 2K5 ppm parts of air. In our patient little or no precaution hud been taken to ovoid inhulution of solvent vapor or contamination of the skin since tetruchlorocthylcne wus repurded us being "practically nontoxie." Symptoms of narcotic cllcct on several occasions preceded the episode of uculc illness characterized by jaundice. It scented clear that this man hod absorbed tetruchlorocthylcne in substantial amounts. The temporal relationship of the onset of ucutc hepatitis to repeated hazardous exposures suggests that solvent intoxicution was either the sole cuusativc factor in the illness or a contributory factor in rendering the liver susceptible to ultuck hy an infectious agent. These two eases show injury to workmen resulting from Ihc permission of inexcusably cureless bundling: of compounds of a relatively low order of toxicity, but dif ficulties also may arise in dealing with solvents ucccpicd us highly toxic when the-measures provided for the con trol of exposure to them ure either inadequate or un enforceable. NAUSEA AND VOMITING CAUSMI) HY I.XI'OSIIHI: TO CAKHON Ti l KAail.ORItM ( asi .1.--A while female luhorutory technician, aged 2h. reported to the bureau nf industrial hculth of the C incinnan Heulth Department that she had fttst become ill on the job while handling curbon tetrachloride. She compluincd of nausea und hcuduchc und had been unable to Hike her lunch. She was em ployed in the duality control laboratory of u manufacturer of roofing materials. A principal job duty was the solvent extraction of usphull from samples of roofing puper. T his was done accord ing to a stundurd specification hy boiling strips of the usphulftmpregnuted puper in u I.IXKI ml. heuLer of carbon tetrachloride on an electric hot plate inside an enclosed hood equipped with un exhaust fun. The strips in the beaker were ugmttcd ut intervals of two or three minutes during the 2(1 minute extraction period. Extracted mutcrial and spent solvent were poured off into a drain inside Ihe hood once nr twice during each extraction and the beaker was refilled. A glass sliding puncl on Ihc Iron! of the hood was raised for this purpose. Icmpcruturc und humidity in the luhorutory room were controlled hy air conditioning. Ihc girl had worked on this job for a period of two years Shortly after being hired, on a day when the odor of carbon tetra chloride Was Strongly perceptible, she hud had headache, nausea, and vomiting, causing her to lose three days Irom work. One year lutcr a simtlur episode occurred, und again she was oil work for scvcrul days. She now experienced nausea on days when out side wind velocity was so greut us to interfere markedly with the * H H. n<J In Srriull Inoutiry. A M A. Aixh H. K.: IcUathliifrihklrnr hiftmuti IfkluM mi iSrfM I |VV J.A.M.Am Hr*. I*. |f*4 4CtH%n of ihc hood exhaust fan. I he (line** repotted to the hculth department hud its onset on such a day. 1 here w% improvement idler hernu outside Ihc labor.uoiv for several hours, although hcuduchc periled during the evening. < *si 4 --A white femnlc hr hoi .nor y technician. aged 22. employed on ihc same job ns ihc woman in caw 1. complained of nausea und belching und unable o take her lunch on this duy While die hud never been o ill as in rem.iin oft work, die did report mild nausea when die detected u hcavv odor of curb.in letMchloridtf in the luhorutory'. I ho occurred on the uveiugc of once weekly. An inspection of the luhorutory wus mude u tew horns after the report wus received. 1 here wus s;iid to huve heen little ehunge in conditions since the onset of symptoms in the technicians. Humpies of air collected ut the breathing rone of workers si finding ill the hood conmmcd curbon tciruchlondc in average coneentra* lions of from 10 to 144 ppm. Air movement ut the opening fuec of the hood varied in vel-v* ity from zero to ?0 ft. per minuic. ti wus determined thut the ex* huiist fun wus toliilly inefleciti.d in removing contaminated uir from the hood under eeriuin recurring conditions of ooiside wind velocity und direction, such us occurred on the duy of our inspection. At these times positive pressure wus ercuted inside the hood. Ihc direction of uir flow wus reversed, und contuminutcd uir entered the workroom when the front puncl wus ruised. Rceom* mendulions were mude for redesigning the exhaust system with the erection of u short stuck to curry off the vupor. Periodic deter* minuiions of the effectiveness of the proposed changes und udded precautions in the bundling of curhon tctruchloridc hy the teehm* ciuns were suggested. Substitution of u less toxic solvent wus not possible hecuiisc of standardization of the extraction technique. Curbon tetrachloride, it highly toxic uubxiuncc. wits heinj! used in these coxes under conditions erroneously repurded as entirely safe. These two euscs arc reported for the purpose of emphasizing that complete safely in the handling of this treacherous solvent can he assured hut rarely, and never when provisions for the protection of personnel arc inadequate or unenforceable. In general, the principle of suhsiitution of u less toxic mutcrial should he followed whenever possible. TOXIC AMHI.YOPIA <*Al'Si:i> HY rXPONUKI. TO MUHAMU ( am .5.--A Negro laborer, aged IV. wus udmitted to < incin* nuti General Hospnul completely blind, compluining of vomiting, uhdommut crumps, und severe hcuduchc of two days' duration, with increasing loss of vision us the other symptoms hud *h* sided. I he onset occurred 4K hours after u Saturday night drink* ing hom during which he hud consumed ut least onc*half pint of u mixture nf wine und uhoiii un cquul pun of u clear, color* less liquid thul he hud druined from u mctul drum ut his pl.icc of employment. On udmission to the hospit.il he wus not acutely 111. There was slight injection of the conjunctiva. Ihc pupils were diluted equally, measuring A mm. in diameter. Neither rcuclcd to light except for oecusional slight hippos on strong stimulation, hui hoih eontructed briskly on convergence. I here was slight mar ginal blurring of the optic disks. The rciinu wus normal except for the peripapillary regions, which were slightly edentulous, wilh reduced transparency und obscuring nf the deeper blood vessels. The curbon dioxide cupucit) of the plasma was 41 vnl. ' and the concentration of chlorides 47n mg. per 100 cc. Ihe resulis of lesis of liver function were within normal limits, the hemo gram wus normal There were numerous hyuhn east* in ihe urinary sediment on admission anil unit a few on %ub%cqiicni days. The urine had u pH of 5 n. -\ specimen was toted foi ihc presence of formic acid b> a gallic acid method beloie and aftci reduction of portions of the distillate to fornuldchidc formic acid was found to be present in high concentration' T he puticnt worked m u plant engaged in the reconditioning of metal drums. He had drained (iff liquid from the bottom of a returned drum, thinking it to be grain alcohol. Ihe drum w.is found to have contained a lacquer thinner composed of "hydro* carbons 50'* , mixed alcohols 2*'r. und butanes or esters 2V* " Three other men uio hud drunk some of the udiilteruied wine ARC 001317 V|, 156. Sn. 3 MM Al.t.H) SAW. MH.VKMV-m CillKS 137 On- nl these. the patient in c*c K w.i* admitted 10 the hospital it the umc lime with Io** of vision *tnt uchIo*<* und the olhei m*o wcie muI o have hml nausea and vomiting. |hw- p.utcni admitted Hi.ii w,(* common piaciicc for employee* in dunk m.ilcu.il horn leimned diom*. although thi* .<* in violation ol company tide* lie wa* di*chaigcd improved, cvecpi loi lo%* ol wonn. on the ninth hospital d.i>. I luce month* later he Mill could hatch peueivc movement m Hi|iln light. amt both opin disk* wcie m.nkcdly .iiioplued C am ii. \ Scion j.miioi. aged Ml. when hiought to < meinnull (ieiiei.il Hospital wa* asuicty ill. with imp.mcd inhii ol i^ao day* tlnriiiion. On the pieviou* Saturday and Sund iv he lt.ul dnml till|2C amount* ol the lacquer ihmnei de*ctihcd m ea*e V the tinsel of symptom* oecuncd unit severe he.nl.iche on Mon il.iv nliernoon A leu (tout* later he began to vontn. He hee.otie mentally contused. resile**, .uni ilien disoiientcd. Iheie wa* piogiossive dimming ol vomit on Monday night ami luesday. On admission to the hospital Wednesday morning he wa* unable It* perceive litliil. I he conjunctiva* were slightly injetieil. 'I he pupil* were widely and equally dilated and did not react to light. On fundtiscopic examination then* was slight edema ol the retina* at the periphery of both optic disk* und macula*. Ihc cat bon dioxide capacity ol the plasma ua* Mk vol. *. the concentra tion of chloride* ua* M mg. per 11KI ce.. und the hloikl had a pH of 7.2K. I he result* of test* of liver function were within normul limits. I he hemogram was normal. I he urine had a pH of h. und a trace of ulhumin was found, ihctc were no ca*t* in the sediment and no reducing substance* by the Benedict te*t. Sodium bicarbonate w.i* uilmim*tcicd intravenously over a pcii.t.l of 12 hoiii*. with eon*iderable clinical improvement. H> the third hospital day the patient was lully oriented I here was no Itjjht perception by the right eye und only slight perception by the left. I he right pupil was lived, and the left reacted sluggishly to light; he was unable to converge. I he fundi weic unchanged. An electioeaubogram on the fourth hospital day had a I wave of low soilage in lead* I and 2. with invcr*iou of the I wase in lead* V V. V. V.. interpreted a* indicating non*pcctlic myo cardial damage. A needle biopsy of Ihc liver ua* taken on the *i\lh hospital day. nine day* alter mge*tion of lire alcohol. I hi* ua* reported a* .turning a few foci ol nonspecific liver cell nccro*t*. The patient wa* discharged on the ninth hospital day . On examination live week* later hi* vision wa* V2M0 in each eye. He wu* barely able to lind hi* way through door* and to avoid large object*. I here w.i* mm pronounced optic atrophy with deep cupping of both disk*. ( 4*t 7.-- A Negro laborer, aged 55. was brought to the < incmnati (ieucr.il Hospital receiving ward because of the sudden on*ct of loss ol vision He staled that he had been in good health until the day before, when he had nau*ca. (ever, chills, wcakne**. lighthcudcdnc**. cxcc**i*c thirst, and mild shonne** of breath on exertion. On wakening ihc following morning he w.i* unable to perceive light with ihc left eye and only pariiullv with the right. While the other symptom* improved during ihc next 4K hour*, he gradually lost remaining vision in the right eye. He wa* admitted in the hospital for study eight dav* alter ihc onset of symptom*. He w.* mm able to perceive light lor the !ir*i time in four day*. I he pupil* were equal, markedly dilated and did not read to light oi awcomimklaiion. Ihc itcular lundi were of normal appearance 'Ihc patient at hr*t denied the ingestion ot methanol or any other unusual substance, but stated that he often drank whisks over week end*, ordinarily "X" bi.ind. and hail l.tsi it.id .i dunk two day* before the onset nl symptom* He had been employed for 15 sear* in the opeiation of a wa*h tank in which u*ed metal drum* were dipped in sodium hsdioxidc a* a tn*i *icp in rcvondtiioning I he drum* uc<c re*ei*ed from local indu*m.d plant* and usually had contained some chemical compound I tghi oihct men engaged in the same work apparent!* were in good health I he manager reported that, while u ua* siricil* agai.isi plant rule*, it ua* common practice for workmen io drain the resid uum from drum* that haJ an alcoholw odor Ihc p.iiieni wa* last ob*cr*e*l to do tbi* one month hclotc the on*ci ot illnc** when he Idled n houlc from u drum and drank j portion of i: Near this man * work station at the plant un empis whisky bottle labeled "X" brund wu* foun*l. Ovci ii pcriikl of 12 month* there wu* gradual imorovcmcnt of visual acuity to maximum uncorrected vision of -right esc ami 4/2IKI left eye. with residual evidence of optic uirophy more maikcd on the left side Methanol poisoning arising out of industrial exposure i\ secoml;ir\ in importance to that due to ingesliiin of adollcriitcd liquors. A feu validated cases of poisoning of workmen following the inhalation of the vapor of melhanol or absorption of the liquid through Ihc skin have been reported, liven some of these hear the suspi cion that the solvent maj have been ingested as well. 'I he chief dttnger of its use in industry still is the tempta tion to drink it. T he eases described here, while not com pensable as being due to occupational disease or injury, might have been prevented by closer control of solvent handling. The two unrelated episodes of typical methanol poisoning with blindness in men engaged in the recon ditioning of metal drums have led me to regard the dis order as an unusual risk of this occupation, related to the temptation to drink from chemical containers that have the odor of alcohol. In all eases of Monday morning blindness Saturday night drinking habits should he con sidered and industrial sources of methanol investigated. Sl'MMAKY There is danger in the handling of ull solvents, al though tire and explosion are feared more commonly than arc hazards to health. The selection of a striven! for a specific industrial use is a compromise between tech nological requirements and considerations of safety. Significant absorption of organic solvents by workmen may occur as a result of cither one of two errors: the acceptance of inexcusably careless handling of com pounds of relatively low' toxicity or the provision of inadequate control measures in dealing with more toxic ones, instances of pulmonary edema following exposure to methylene chloride and of acute hepatitis in u man exposed to tctrachlorocthylenc arc described as examples of the first type of error. The second is illustrated by the report of eases of illness due to exposure to the vapor of carbon tetrachloride and hlindncss Irom the ingestion ol methanol obtained at work. I den and Hclhcsdu Avcv lIVi. The Biological Approach to Immunity.--In u world (hat is full of microorganism* capable ol infecting living U*mic>. it is a positive necessity for survival ih.it mn*i experience* of infection by an* given microbe should be followed hr*t by recovery and secondly hy a persisting insusceptibility to un attack of ihc same disease. . Perhap* Ihc important factor in the development of the particular type* of immune reaction with which we arc (amih.tr m man wa* the evolution ol ho mammalian ancestor* tor ihc most part a* relatively solitary arboreal animuK in uopic.il jungle*. In such environment* it *ccm* likely that the major type of pathogen that woul.l he encountered would he iho*c protozoa und ' iru*c* spread hy in*cei--especially mosquito __wetor* It i* noi improbable that the type of immunity charac- ioisti* of human being* i* c**eniiully something evolved to deal ellcsiively with mlccuon by mo*quiin-hornc viru*e* of the scllow-tocr type At least we can be *urc that immunity i* a mcen.mism that ha* been evolved to deal wtih ihc entry of foictgn mieroorgam*m* into the body, and that it hus been perfected hv the normal prove** of selective survival--Sir Macfailane Hornet. Ml). 'I he Newer Approaeh to Immunity in h* Hejnng on Medicine and biology, &mnh Mciiuul Journal. July N. APC 001318 J. T. HOBBS HO US TRIAL HYGIENE COMMITTEE ALCOA FABRICATING PLANTS COPY April 27, 155 to: DR. LESTER V. CRALLEY INDUSTRIAL HYGIENE DEPARTCENT PITTSBURGH Re: CONTROLLED ATMOSPHERE GENERATING UNITS Not long ago we had an unfortunate experience at the Alcoa North Plant which could have had serious consequences. Le felt that it would be worthwhile tc give you a general account of the incident in the hope that the information might be of benefit to other plants. Two brick masons entered the combustion chamber of a controlled atmosphere generating unit to make repairs. They did not open all available ventilating parts or provide any forced ventilation of the chamber. The men were overcome presumably by residual CO or CO2 gases. Luckily, both were removed from the chamber quickly and given treatment at first aid. Henceforth, at Alcoa no one will enter these chambers without opening all parts and providing forced circulation. An attendant will always be on hand outside the chamber to provide immediate aid if necessary. Best personal regards J. T. HOBBS !TH:L? APC 001319 O tfl 8 Tg 5 -V~J3l oro OM ?nfMtsr so cmo -w U1 > *fTtJ Oso 1M fot tm-3 3 ft M M> o U> M o OVJ1 I-- D 3 ffott o ft- W M *-3 O CO 3 '= X O >e MQ M SC o > > *3 W JO o C2 SM ft 63 K - - *T3 _ SO -8 *r k-3 Jr H X So m3 VO M U1 O wR / Sound Pressure ro O Decibels uo> 0* o* APC 001320