Document 6wjmpqgvp7VEBMadR4o9dGB03

FILE NAME: National Safety Council (NSC) DATE: 1938 Oct 12 DOC#: NSC188 DOCUMENT DESCRIPTION: Excerpt - Transactions of the NSC Pamphlet - Silver Jubilee Safety Congress - Dust, Fumes, Gases and Vapors Dusts, Fumes, Cases and Vapors W EDNESDAY M ORNING SE SSIO N October 12, 1938 Assembling in the Grand Ballroom of The Stevens Hotel, this meeting was called to order by Chairman Walter S. Paine, Manager, Engineering and Inspection De partment, Aetna Casualty & Surety Com pany, Hartford, Conn., and Vice-President for Engineering, National Safety Council. Chairman Paine briefly outlined the session objectives, and then introduced the speak ers. Recent Developments in Detecting Hazardous Dusts, Fumes, Gases and Vapors By W A RREN A. CO O K Superintendent, Engineering Department, Zurich General Accident and Liability Insurance Company, Ltd., Chicago In discussing the determination of injuri ous dusts, fumes, gases and vapors, 1 am very sure that you arc not interested so much in a meticulous dissertation on such phases of the subject as whether the loga rithm of the reciprocal of the hydrogen ion should be 9.5 or 9.0 for the determination of lead by the dithizone method, but rather iu a discussion of this matter along broad lines, pointing out what types of potentially injurious materials should be looked for, whether determination of them is in order, a brief discussion on some of the more im portant and common methods of determina tion, and interpretation of the results ob tained. Foolhardy to "W ork in the Dark" Working in the dark without any means of illumination where there may be hazard ous conditions serious enough to cause loss of life or severe injury would be considered most foolhardy ; yet every day men conduct their operations in atmospheres containing dusts, gases, and vapors which may cause death or severe injury to health without be ing able to see or otherwise perceive the potentially hazardous condition. Most gases and vapors can no more be seen than the well-known black cat in the coal cellar. Some of them cannot even be detected by odor, though odor is itself no reliable criterion as is evidenced by the gas, hydrogen sulfide, which has a most ob noxious odor but lias caused many a case of poisoning. How, then, are we to know whether the atmosphere in which we work is safe or injurious? Arc we to wait until we see the effects of unhealthful or irrespirable at mospheres on our men or is it not more intelligent to determine, within the limita tions of modern methods and practical ap plications, just what sort of atmosphere we are subjected to? The importance of having facts before us is well illustrated by an atmospheric con dition where a life could be snulfcd out in a few minutes, even though the more com mon situation is where excessive exposures may require weeks, months or years to cause their injurious effects. 45 4# S i k r r Juhiiee Safety Ctaitjress Thirteen years ano 11ti> month a powder crew was walking down the tunnel nt a new water supply system of a Lonnectirut city. Their duty was to inspect the root and the face, to see that all the shots were tired. On approaching the tunnel heading immediately after the blast, they found that living rock had broken the compressed air line, which had keen left turned on in order U> blow the smoke and gas away tmm the face of the tunnel. The crew, consequenth. ran into a heavy blanket ut smoke, hut they were hardened workers, used to smoke and gas. and a little smoke, even though they knew it contained carhon monoxide, did not hold them hack. They found the root intact, lint tour oi the holes had not tired. Caps with o-looi fuses were inserted in sticks oi dynamite, one for each of the holes. 'Idle gas condi tion by the time this work had hern ac complished was beginning to make the"* men feri a lot groggy, hollowing the usual practice, the powder Joreinan -111 iiie icsl of the men hack down the tunnel beiore lie lighted the fuses. The men walked hack through the "moke to the car. about a quarter of a mile down the tunnel. There they waited lor the loreman. Seconds passed. I he* time stretched to a minute. l)own the tunnel came the boom of the blast--but no foreman. I lie men rushed to the heading and lound the foreman stretched on the tunnel lloor. nearly covered with rock Irom the fila^t. where lie had collapsed irom the Hierts m the carhon monoxide. Tins a true story up to a certain point, hut I have omitted a part ot the story, and the eliding. I am glad to say. U pure fiction. The part *f the- story which I omitted was that carbon monoxide determinations were being taken when those men got up to ihc heading, and a concentration of .a per cent carhon monoxide was shown to he present hv means of the lloolamite carbon monox ide detector. With such a high concentra tion. it was realized hv the man making the determinations that it would not take long for exposed persons to collapse. He in formed the crew of the condition and hur ried them back to the car to wait until the smoke and gas had cleared enough to per mit them to work safely and fire the blast. The difference between fact and fiction in this case, between a brief delay and a fatal caso of i-arhot mouoxide poi-oiime, th ready availaluiily of a "iniplr meati" <, detenni ni ug 11ir ca rh<>n motto \ ide c 0 n*tr:tration mi th p*b The prescnt tendmev m dc\riopment >r inethods of <Ir:r ntunat wu ni miiitiou- ma teriaK in air n toward sneh "iinple, quickacting devi e-, \s mam >i voli kuow. tP I loolaniite cnrh<m mouoxide detector *ipcrate" mrrelv by pn-sAng a vubln-r bulh ter times and cutnparing a purple color wIlici dcvelopx m pre-ence ni carbon mni)n\ii|( with a standard co!u- scale mottnird mi t!:. instrumeut- :m "peration v\ bici) rrquuxabolii a minute, [n-triimmi- ot ibis typ are e"prriall\ imporiaut i"C ga>C" wIlici mny cause acute pn-oiiing -urli as cari; nioiioxide. hy drogai cvanide, and hydroger -lllphide. A n ms t r u me i i t n r d e t e r m i n a t i o n oi Ii\ d r o g e n t- vani de. s| m i i a r !<< 1he l h><daini'.-. c a r l m11 llli U K i d e i I e t r r p u\ h a s 1 ee< nt i \ b e e n de\ e l o p e d h\ t he 1 llip.d S t a t e s IS l e a n ot M m e w 0 r ix e r - s . a n d . t o g e t h e r v. it;- a n u m h e r - f o i l i e r oi t hes e -Ampl e d<la'- 1. , 1-s. I" in 1vx .1 a ; !ai de c o m m e r c i . d l \ . Ik t e r m i n a t i o n <>1 - m e ; i) m a t e r i a l - c a n a r c m; m g l \ be m a d e m uci i ni u w idt iy ;1at; to r n i e r l v w lieti lab or i oi i x c h e m i c a l !ah ora- !<if v met 1m u P w ei'e ne c c s . a r \ . Potentially Hazardous Materials The first '!;. m an oi ga m/ ed riideav"' to avoid environmental condition-* wine:, may cause injur-', to health is a listing 01 ai= materials, n-md *>r prodiie ed. wInch ma\ limler OTtain conditions he deleterious. I: was found in a -m<i\ by the I'nited State* Public Health Service oi poKiiital hazardin a ivpical indu-trial area f | ) that a con siderable percentage, nearly 20 per cent, the workers were exposed potentially t' arbon monoxi de. The reporl by no mean* intimated that this percentage ot workerwere being poisoned by carhon monoxide hut rather that if tilings went wrong and a concentration ot the g a s built up to in j u r i ou s proportion, these men might be come poisoned. So I suggest that you go through yotr plants and see what operations involve po tentially injurious materials. Of the dust?, those which may produce silicosis occur not only in the well-known industries where mnior studies ot conditions have been coll' ducted but in other industries as well, though usually to a Ic-ser extent. In silver D u sts,'l; times, Gases and Vapors 47 ware manufacturing, for example, .me man may be exposed day after day to tripoli dust in making up a polishing compound fur use within the plant. A list of iii.lus tries in which such dust exposures may exist is given in the report of the National Silicosis Conference/ The toxic dusts and fumes are more readily spotted. We recognize and guard against lead exposure in storage battery plants, but often overlook such an operation as where red lead is being mixed with a vehicle bv a worker in one corner of the top tloor of the plant to color lettering on a steel part. It is not so much whether a pound of lead or a ton is used in a day, lint the extent to which it contaminates the air breathed by the worker. Carbon monoxide, hydrogen sulphide, hydrogen cyanide have been mentioned as examples of gases. The first ot these oc curs where producer gas or water gas is iiM-.b The last named should be looked for where fumigating may be done from time to time. Where dry ice is used in rpiantity or fermentation processes are conducted, carbon dioxide is liberated and has caused .baths usually at the bottom of confined areas such as ships' holds and fermentation tanks. V'apors are present wherever organic solvents arc used. Death may result quickly where high concentrations exist as has oc curred when a drum of solvent was dropped on a basement storage room floor and split open, and again where carbon tetrachloride was being used for fumigating a Ilnur mill and the fumigator sprinkled the liquid in the basement as his last operation. It was his last. Injury from continued exposure to sol vent vapor at concentrations which cause their effect after weeks of exposure is the more common condition. The various solvents differ widely in the concentration of vapor necessary to cause injury. These are divided into groups in accordance with their toxicity in a paper delivered before the North western l niversity Symposium on Occupational Diseases a r ear ago.* Where Should Determinations Be Made? After going over your plants and learn ing where potentially hazardous materials are present, it is my suggestion that, before Making actual determinations of concentra tions in air or instituting control measure', you make a thorough survey of the condi tions and divide the various operation' where these materials are pre'.-iit into groups: (1) those which are obviously safe: (2) those which are admittedly caus ing injury to health or are worse than good industrial practice dictates; (2) iho'c conditions where it is not readily discern ible by general observation whether the ex posure is within safe limits. Certain conditions we know definitely and can say definitely will not cause injure to health. I would not sav that tlio'c arc to he forgotten, hut at least tiny need imt he the subject of initial action. If. for e x ample, a gas containing .10 or 40 per rent carbon monoxide is used for hot plates, and those hot plates are connected with rigid conduit rather than with rubber tub ing, you can feel reasonable safe that the carbon monoxide exposure i' eeithin 'a ir limits, and 1 would not recommend that determinations he made. Where -prae painting is being done in a well ventilated booth in sueli a manner that there is m. excessive rebound into the face of tinsprayer, determinations of vapor or pigment need not be made even though the odor of the solvent is detectable. l-'rom time to time it may lie well for state authorities to cheek some of these lesser exposures, hut there is a considerable number of such e x posures which can he accepted as safe. The second group of exposure'--that where conditions are admittedly severe--i< another where determinations are not c'seutial. Institute control mert'itres immedi ately. If there are cloud' ot .lust contain ing free silica in your plant, g o to work o n them. If excessive lead ab-.option is shown by development of symptoms o r by liigli basophilic aggregation percentage', reduce the lead exposure. It may he desirable to make determinations even in these cases either to provide a before-and-aftei' picture of exposures to show what improvement is effected or to obtain a clear picture of iust what part of an operation is responsible for the excessive cxpo'ure to the end that con trol measures can be more specifically ap plied. This latter use of air analysis data is of especial value where the materials are invisible as is the case with gases, vapors and even some of the more toxic dusts such as quartz and lead. The principal use for determination of