Document 85MqB272vKpp2KEzb0gOoVn3o

MECHANICAL ENGINEERING Published by The American Society of Mechanical Engineers Volume 57 Number z Contents for February, 1935 iPCAlNTIFeSi AiiJfailriff' LABOR-MANAGEMENT COOPERATION IN METHODS DEVELOPMENT . . . ......................................................................................... R. C. Nyman THE AUTOMOBILE OF 1935 1.......................................`.................................................................... 1 APPLICATIONS OF SCIENCE TO THE MAKING AND FINISHING OF STBBL . ......................................................................................... John Johnston engineers' business contacts . . . . ' . . . A. G. Christie OCCUPATIONAL DISEASES-----PROBLEMS OF PREVENTION . . F. R. JoneS ADMINISTRATION OF OCCUPATIONAL DISEASE CONTROL . . A. S. Gray toxic dusts--origin and sourcbs in industry . . R. C. Stratton progress in power............................................................. C. F. Hirshfeld 79 87 90 92 95 99 THE APPLICATION OF CENTRAL-STATION PRACTICE TO DOMESTIC HEATING ................................................... . . . ... . M. K. Drewry 103 *, EDITORIAL .... \ ENGINEERING PROGRESS LETTERS AND COMMENT 69 110 122 .A.S.M.B. BOILER CODE . . . 125 BOOKS RECEIVED IN LIBRARY .' . 128 what's GOING ON . . . . . 129 DISPLAY ADVERTISEMENTS . 1 PROFESSIONAL SERVICE . . what's NEW .. . 14 CLASSIFIED ADVBRTISBMBNTS INDEX TO ADVERTISERS .... 32 OFFICBRS OF THB SOCIETY: Radi E. Fundui, Pmidmt Erik Obbko, Trtaturtr C. E. Davibr, Stertiary PUBLICATION STAFF: Gborob A. Stetson, Edittr Frederick Lask, Admrtiting Mgr. COMMITTBB ON PUBLICATIONS: I S. W. Dudley, Chairman S. F. Voorhbbs G. F. Batsman l W. F. Ryan M. H. Roberts ADVISORY MBMBBRS OF THB COMMITTBB ON PUBLICATIONS: E. L. Ohle, St. Louis, Mo. E. B. Norris, Blacksburo, Va. A. J. Dickie, San Francisco, Cal. Junior Member, O. B. Scbibr, 2d Published monthly by The Americas Society at Mechanical Engineers. Publication office at 20th tod Northsmptoo Streets, Hattoo, Pa Editorial sad Advertising departments at the headquarters of the Society, 29 West Thirty-Ninth Street, New York, N. Y. Cable address, `'Dynamic," New Yore. Price SO cents a copy, $5-00 a year; to Octobers sod affiliate!, 50 cents a copy, $4.00 a year. Pottage to Canada, 75 ccots additional, to foreign countries, $1.50 additional. Changes of address oust be received at Society headquarters two weeks before they arc to be effective on the mailing list. Please tend old as well at new address. .. . By-Law: The Society shall not be responsible for statements or opinions advanced in papers or... printed in its publications CB1, Par. 3). . .. Entered u second-class matter at the Post Office at Bastoo, Pa., uodcr the Act of March 3,1879.... Acceptance for mailing at special rate of postage provided for in section 1105, Act of October 5,1917, authorised on January 17,1921.... Copyrighted, 1915, by The American Society of Mechanical Engineers. OCCUPATIONAL DISEASES'" The Problems of Their Practicable Prevention in Industry By F. ROBERTSON JONES ASSOCIATION OF CASUALTY AND SU1ETT EXECUTIVES, NET TCU, N. T. NDUSTRY has so many and such a wide variety of major chargeable to health-hazards which industry itself creates. I problems these days that to many the problems presented by occupational diseases among workers may seem com Even that is too broad a subject for me to deal with in a brief introduction. Therefore I will restrict my remarks generally paratively insignificant. This is, however, far from being theto prevention of occupational dust diseases of the lungs, with case. Either from the standpoint of cost or of social better particular reference to silicosis--since those diseases, of which ment the situation confronting many employers as a result of silicosis ranks first, have now given rise to a problem of such their growing liability to provide compensation for or pay magnitude and pressing importance to industry as, temporarily damages to the victims of occupational diseases is equally as at least, to relegate other occupational diseases to a position of serious as the ever-increasing tax rates and the prospect of relative immateriality. - - soon being compelled to contribute to unemployment insurance From what I can learn the disease now known is silicosis is funds. Speaking as a representative of the largest stock as old as history. But whether because of a recent increase casualty insurance companies of the country, I can assure you through the use of modern machinery, or because of a growing chat companies are well aware of the almost overwhelm public recognition of its seriousness, or because of these two ing burden of cost which seems about to be heaped upon factors in conjunction, and possibly others also, silicosis has industry by the general extension of the compensation system now become a mortal menace to industry. Whether under a to cover occupational diseases of all kinds. Our companies, system of employers' liability for damages or under a system of course, have only what might be called an indirect interest of compensation--"regardless of fault" for occupational dis in the problems you are discussing, but they will be adversely eases, die cost of silicosis is becoming so heavy as to entail affected if necessary insurance costs grow so great that they the rapid or gradual ruin of many industries, ualesa the inci will be "more rh*n the traffic will bear." They are naturally dence of the disease can be radically, reduced. The cure of tremendously interested in these problems and anxious to silicosis, once it has progressed beyond a very early stage, is, cooperate in their solution. It is my opinion, which I believe} according to the preponderance of medical opinion, practically firmly to be well founded, that the primary essential in meeting out of question. Consequently, for silicosis, frrmtim is most the problems of occupational diseases is prevention. If these ' emphatically the primary and principal problem. diseases, through engineering and the medical sciences, can That problem has engineering, medical, economic, legal, be reduced to the level of exceptional misfortunes, the remain educational, and political aspects all of which need to be ing economic and legal problems can be readily solved. It realized by all concerned in the task of prevention. - therefore seems to me that most intensive consideration should In its engineering aspects, the principal problem in preven be given to this phase of the situation immediately by the tion of silicosis is the removal or prevention of inhalation outstanding experts of the country, so that suffering by work of duat. Aa a layman I cannot imagine how, practically, all men from preventable maladies may be reduced to a minimum dust can be removed or kept from inhalation. Therefore, and so chat industry may not avoidably be drained of its primarily at least, efforts should probably be directed princi resources. The character of this meeting and the program pally to the flwntwrinw of harmfal dusts. Here you are con to be presented indicates clearly that The American Society of fronted with several difficulties. The preponderance of medi Mechanical Engineers is alive to the situscion and has the cal opinion is that, of the inorganic dusts constantly generacad cooperation of the medical fraternity in its most laudable in industry, only dust of free silica- (silicon dioxide'), and objective of prevention. perhaps asbestos dust and these dusts only when in minute The specific subject for discussion at this meeting is the particles--are harmful, that is, harmful in the sense and to "Engineering Aspects of the Prevention of Occupational the extent of cauamg_specific -- of rhe-limgs.. Disease." It is not my purpose to much to enter into this But that is merely a majority opinion, from which there are subject as racher to lead up to it by calling to your attention dissents; and it is open to doubt. Only a Jew months ago a some aspects of the problem not special to engineering but high authority1 on this subject in Gnat Britain declared: which industrial engineers should study and bear in mind. "We need a scientific 'recessioaal' in which to reexamine From the start, it needs to be borne in mind that all forms with aa open mind many of the generalirations now accepted of ill health--"occupational" or of ordinary life--to which as current coin in relation to sflfcnsihand `miners' phthisis.' ** industry in any wise contributes, as, for examples, through Moreover, silicosis is, in colloquial language, "all mixed up defective lighting or ventilation, or excessive exertions, or with" tuberculosis. Apparently, tuberculosis induces ailicoaia. exposures to the inclemencies of the weather, are matters for and silicosis lessens resistance totnberealoam, or something prevention. That, however, is a cyclopedic subject. You like due. Bur tnberculoaia may be caused by organic dust or, have advisedly restricted your discussion at this session to the for'all that I can learn to the contrary, may bt indirectly topic of temfstimud diseases--which I construe to mean--in activated by other dusts. Consequently, how far all dusts, popular phraseology--those diseases, not of ordinary life. or, if oat sil, then what dura imperatively need to be elimi Contributed by the Safety <*'--t.-- mi uuemi at tbs Aanusl Messing. NswTarih;M.^r^Dsaasihw317,1934,ofTtafeauu* nate ia, as yet, a problem to be dcitnnintd largely by expert- 1 Prof. &. L. Cummins. Adviser to the British Tfocrcnlosfe Kocweh Committee, quoted in hitmitl MtJUm, April, 1934. Fbbxctat, 1935 91 mentation, not based a priori on present medical opinion, bat an the results of experience--on the resalts in the way of reducing morbidity from the use of specific means for preven tion, engineering means among others. A problem of vital importance in the study of engineering means of prevention is the determination of what is practi cable--economically and humanly. Economically, the best means for prevention may often be impracticable. Industry cannot afford to be continually replacing in machinery to experiment with the latest gadgets. It would be a jump out of the frying pan into the fire to load an industry to death to prevent exposure to an occupational disease; and some means of prevention may be such that the workmen simply cannot be induced to use them properly and consistently. This prob lem will be particularly acute in the smaller undertakings. What is practicable in large and well-organized establishments is often impracticable in minor operations. Thus in the prevention of lead poisoning, the well-established paint fac tories have been almost completely successful, whereas among che job painters the incidence of that disease has been very little reduced. Resulcs will probably be similar as to silicosis. In South Africa, where silicosis seems to be concentrated principally in mines, generally large establishments, measures of prevention are succeeding in reducing the incidence of the disease, encouragingly; but in Cumberland County, New South Wales, where a scheme of compensation for silicosis applicable to such small-job trades as quarrying, rock drilling, sewer excavation, etc., is in force, it seems that little progress in prevention is being made, though strenuous medical "<< are resorted to. It may turn out to be a job for engineers to discover means for prevention of silicosis practicable for the "little fellow." At least that point will require study. This question of what is practicable, as distinguished from the ideal, leads up to another aspect of the matter. In my opinion, besides studying the best practicable ways and means for prevention, engineers hnld also give consideration to the formulation of mhimtm standards, and to ways and means for procuring their observance. Authoritative formulation of such standards is needed for many purposes--to impress backward industrialists, to guide and support insurers in granting or refusing coverage, and to furnish a scientific basis for regulations to be enforced by public authorities. A code of such standards needs to be elaborate, so as to fit different conditions, and to be open to continual revision, to keep abreast with the developments of research and experience. A present obstacle to prevention, not often realized but of no mean importance, is that many states have laws which impose upon employers iivUfiniti obligations for the protection of the health of employees, such as to provide "adequate" venti lation, and to do this where "practicable" and to do that where "reasonable," subject to liability for damages for non-com pliance, leaving it to juries in litigated cases to determine what is "adequate," "practicable," or "reasonable" under the circumstances. How can any of you expea an employer to go to much expense to follow your advice when an ignorant and misled jury may mula him in damages for not doing differently? In my opinion, it is practically essential to pre vention by engineering means to procure the replacement of such laws as these by public regulations prescribing itfmit* standards, for the development of which your cooperation is requisite, and to g rid of the disturbing influences of juries in determining engineering questions by means of the adoption of "compensation" as the exclusive remedy for occupational diseases, for which your assistance would be of great weight. All this that I have had to say has been discursive as a whole and speculative in parts. I hope, however, that it will be of some use to indicate to you the ramifications of your subjea and how the particular topia to be today fit into the broad problem of prevention, in the solution of which technicians in many lines must all cooperate. NDUSTRY, in order to itay in busines* and I m^inrain its position in the economic world of today, most avail itself of all the materials and processes which have been shown to increase The Administration the efficiency and speed the output of its produc tion. New substances and processes and new uses for of OCCUPATIONAL older ones are constantly being utilized by in dustry. New chemicals, plating solutions, dopes, solvents, degreasers, condensation products, varn ishes, paints, lacquers, dyes, abrasives, and DISEASE CONTROL fabrics--substances used to increase and broaden production--are often employed without a knowledge of their possible effects upon health. A fire hazard is eliminated by replacing an in Br ALBERT S. GRAY flammable solvent wich one that is not inflam mable, without the realization that there has CONNECTICUT STATS DEPAXTMBNT OP HEALTH been substituted for the fire hazard a hazard to health in the new solvent. And it is in the use of these new substances and processes (and some of the old) nately, the conditions predisposing to occupational disease are rhir the health of the workers is affected and occupational mote subtle. They are not so attention-compelling as an disease results. accident; they may appear only aa increased labor turnover or This has been recognized by a number of states, and though decreased production. The effect upon the individual is not compensation for occupational disease was originally limited so self-evident, and so the cause of the condition is not to to a few specific occupational diseases, schedules have been readily recognized. gradually enlarged with a tendency, perhaps, toward the There is nothing particularly arresting in the gradual loss of blanket coverage which has already been adopted in a number power in the hands of those absorbing lead; nothing to stimu of states. I am not, however, confining my discussion of late the interest, no startling appeal in the slowed gait and occupational diseases to the limited compensation interpreta mental peculiarities of those exposed to certain solvents; the tion of them, but shall consider them in the broader aspect of development of "" and tiny hemorrhages in those exposed the effect of industrial environment on health. Hayhurst to other poisonous materials; or the gradual development of defines occupational disease as "Injuries and disturbances of fibrosis of the lungs from exposure to certain dusts. The onset health contracted in industrial pursuits or other vocations in is gradual, the change imperceptible from day to day, until lives as a result of exposure to toxic agencies, infectious or the individual either leaves to be replaced by another worker ganisms, or other conditions inimical to health." who passes through the same cycle, or remains at work under Unhealthful industrial environment not only causes specific progressively lessened efficiency until he can no longer work or occupational diseases but increases the incidence of disease becomes s compensable case. If he leaves for employment among the general.population. - elsewhere,- he -continues at work at lowered efficiency for s The life expectancy of the industrial worker is several years greater or lets time, dependent upon how much of the material less than that of those otherwise employed. Tuberculosis ' he has absorbed. The body is capable of wide adjustment to rates are much higher and pneumonia rates twice as high in the environment and much harm may be done before evidence of industrial group. Mortality rates for degenerative diseases the condition is noted. are two to three times as high in the industrial group. Occupational disease is not s new problem but it is only According to the 1930 Census there were more than 13,000,000 within comparatively recent times that we have attempted persons gainfully employed in manufacturing and mechanical to measure, definitely and accurately, its relationship to indus industries and the extraction of minerals in the United States. trial environment. We now know that there is s very definite And in these industries there are more than 900 occupations relationship between the health of the individual and the potentially hazardous to health. environment in which he works. We have been able to estab The control of occupational diseases, therefore, may be seen lish the amount of many of the materials used in to present a public-health problem of the first magnitude. industry that will affect health (which we have called the Mechanical engineers have a tremendous responsibility in "threshold dose"), sad when this information is not available, the control of these diseases, for in the majority of instances the amount which good industrial practice dictates; and we this control is bat the application of mechanical principles, can now measure the exposure of the individuals to these whether it be enclosure, ventilation, or both. materials to whether this amount is exceeded. We The progress of accident prevention daring the past ten or know the amounts of toxic materials sad the processes that fifteen years has resulted in the saving of thousands of lives will affect *"-*>* We-kaow thsx if these various materials and millions of dollars. A much greater saving may be; sad are not controlled they will seriously affect the iirftmpiiihwl by properly health of the individuals exposed to them, aad may even control. There has not been the incentive to prevent the affect the health of die people in the community. occurrence of occupational disease that has been accorded accident prevention, for an accident is self-evident; a man Tax <<M-unrr BOUAO OS OCCOVAXXOMA1. DISXASW slips on the floor, falls, or is burned or caught in a press . Cnnrirrr'urnf, in 1928, recognising the tremendous importance there is no question that he is injured and how. Unfbrtu- of the effects of industrial environment an the health at the Cootribunal by the Safety Cceamiaee and presented at the Annual Meeting, New York, N. Y., TVrrmbcr J to 7,19M, of Taa Awaeis Sectary of Mamocu Eswinaaaa. workers in the stare, set up ss pert oi the State Department of Health, a Bureau of Occupational Diseases under statute which provides that ail cases of occupational disease be rc- 92 FsBRUAiT, 1935 93 ngtrrJ to the State Department of Health and which authorizes (jie investigation of conditions causing or suspected of causing oncBjational disease, and which further provides that reports of occupational disease or the results of investigations cannot be used as evidence in compensation claims. This bureau receives and investigates reports of occupational nude to it in accordance with the statute; makes dirveys and field studies of workroom environment, including epedal determinations of dusts, fumes, gases, or other toxic materials, measurements of ventilation, illumination, etc., or any condition or process thought to be affecting the health of industrial employees, to determine whether the environment is safe or where and to what extent a health hazard may be present. It provides a central source of information for physicians, industry, or any agency interested in the cause, treatment, or prevention of occupational diseases. It maintains in this connection a reference library containing the most recent information relative to the effects of various industrial mate rials and processes upon health, and in addition, as part of the set-up, a well-equipped laboratory. The personnel of this bureau comprises technically trained men, who in the aggregate possess a broad knowledge of industrial hygiene, of industrial materials and processes and their effects on health, and the capadty to interpret the result of a survey or study as a basis for recommendations for control. BUXXAD S FINDINGS RJJPOBTHD TO INDOSTXY F*rb industry in which a study or survey is made receives a complete report of the bureau's findings, presenting the results of actual physical and chemical determinations of the working environment and the exposures of the individuals engaged in it, with recommendations for the elimination or control of any hazard that may be shown to exist. Actual determinations are made of the number of dust particles per cubic foot of air and of the concentrations of toxic materials present in the air to which the individual is exposed. These procedures necessi tate the application by specially trained technical personnel of precise physical and chemical determinations. But it is in the proper interpretation of these results that the existence or non-existence of a hazard is established. It is impossible for a lay inspector to tell by mere inspection whether the dust or other toxic material in the air of a work- is present in sufficient quantities and is of such a nature to constitute a hazard, whether the protection afforded is adequate, or the ventilation sufficient. It is only by measuring exposure to these materials and processes that we can that the individuals exposed to them are subject to jury from them. reports of these investigations are not just to the 'ustry but are presented by a technically trained man and with the officials and engineers of the organization, information not only establishes the nature and extent an existing hazard but provides constructive data which gineert can utilize for the control of the hazard. .-Already the work of the bureau, with the assistance of the Bineering profession, has resulted in defaiire improvement working conditions, changes in processes, substitution of ' " and, in a number of instances, in the purchase of new equipment, not as the result of any mandatory but due entirely to the fact that these industries were definite concrete information on the effects of the environ- on health. The actual requests for this service from r have been so numerous it has been necessary to schedule > months in advance. I say ``with the aid of the engineering profession" advisedly, for the work of the bureau in the control of occupational A'***tr is to render the laboratory and field service necessary to make the determinations of workroom environment, whether they be dusts, fumes, gases, illumination, ventilation, or any mate rial or process chat may affect health--chat is, to measure the exposure and determine whether the environment is safe and if a hazard exists, where and to what extent, and due to what causes, and to present recommendations for its control. If the control involves specific engineering problems, as it fre quently does, that is the job of the engineer; the bureau makes no attempt to provide this type of service, so that in the final analysis engineers have a definite responsibility in the control of occupational disease. 6thz lb op indostxt in thb cosmos, op occupational DXSSABI In any program for the control of occupational disease che cooperation of industry is essential. Possibly one of the principal reasons why industry has been less willing in the past to correct an environment hazardous to health is that little actempc has been made to provide it with definite data. Such changes as have been effected were largely accomplished as the result of arbitrary orders from a law-enforcing agency and no serious attempt had been made to establish the exact nature and extent of the condition. Industry is penalized through compensation payments if ia environment causes occupational diseases, and, if it can be definitely shown that a health hazard exists, realizes that it is a matter of good business to control the condition causing it. But no industry will cooperate to the extent of changing ia processes, installing new equipment, substituting new mate rials, etc., on the mere opinion of a lay inspector that a hazard exists. Under such circumstances it will do only what it is compelled to do, particularly when information secured as the result of such inspection can be used against it either in the form of mandatory orders, claims for compensation or both. With a set-up such as exists in Connecticut, where the law provides that the results of investigations cannot be used in compensation claims, with a specially trained pep. sound to make determinations and interpret the conditions found in industrial environment, industry is provided with just the information it has a right to demand before it is re quired to change ia processes, substitute materials, or take other necessary control measures. Actual determinations of exposures are made in the working environment, and industry is presented with definite concrete facts that not only establish a hazard where it exists but pro vide constructive data for eliminating it. It is our experience chat when industry is approached by a health agency in behalf of a health program and is presented with definite data regarding ia working environment, in a spirit of service rather than law enforcement, with the assur ance that the resula of the investigations will not be used in furtherance of claims against it, it not only sccepa the service as a matter of good business but actually requesa the assistance of such an organization in the improvement of ia general working conditions. TO SNOINXSa't VAST The engineer's part in a properly administered program is of vital importance to successful control of occupational disease conditions. As an integral part of the personnel of the Bureau of Occupational Diseases, the engineer can offer an important contribution in interpretation of some phases of data obtained 94 MbCHAKIOLL EnGOTBDUNO and in the development of recommendation* for control of occupational H'*'***** hazard*. The field of occupational diaeaae control is by no ""m confined, however, to that poop which may give fall rime to this problem. With the awakening of industry to the necessity of providing healthful environment, the entire engi neering profession has a large opportunity foe constructive work. With the data at your disposal developed by the cype of plant investigation I have outlined, you have new tools and more precise yardsticks. In order to perform your part in the control of occupational A you must be prepared to predicate your work not on the amount of air or material you remove but on the amount that is left behind and be prepared to meet a standard chat will keep the working environment safe. To you we must look for the practical application of our findings and recom mendations. It is you who design the machines and equip ment for the use of these materials in industry. There is, of course, a great deal of equipment used by industry that can be safeguarded in so far as the creation of occupational il'twy is concerned by additional protective equipment, but it seems to me that you should keep in mind s* s future develop ment the importance of taking care of the problem in the original design so that hazardous conditions may not develop. Why design s rock-crushing machine without proper dnro> collecting devices, a degreasing which peoniti rnrif quantities of vapors to escape, or an asbestos carding iwKim that subjects operators to 35 "''" particles of doe per cubic foot of sir, when, after installation, these equipments will require additional devices to protect the worker, more expensive and less satisfactory than if the equipment had h~n originally designed properly to protect the operator? Industry is very much alive to the necessity of providing safe working environment for its employees and you have a splendid opportunity through the exercise of your profession to profit and do your part in the prevention of occupational disease. An appreciation of the effects of these materials and the importance of such data as I have outlined is not only essential to the proper perfbsnance of your task, but will go far in convincing industry that the design sad installation of protective devices is not a tinsmith's job but one for a com petent engineer. TOXIC DUSTS Their Origin and Sources in Various Industries By REUEL C. STRATTON . THE TKAVELSU DQOIANCE COMPANT HE SUBJECT aligned to me presupposes that many in Air-flushed drills distribute these particles over a wider area Tdustrial diseases are produced through contact with or in than do water-flushed drills, but the offal from water-flushed halation of industrial dusts of a toxic nature. Personally, drills dries and then becomes distributed in the air. When 1 do not believe that the consideration of occupational diseacsreushers are operated, either gyratory or jaw, dust is produced prevention should confine itself to dusts alone; it should in in an amount depending mainly upon the size of the unit clude all materials produced in such manner chat they may be involved and upon the fineness of the material which is being inhaled by a worker. The question of whether a material processed. exists as a gas, a vapor, or a dust is but one of particle size and Sizing and screening operations also distribute dust, although chemical make-up; but with materials whose source is in in they may not in themselves be producers. dustry, it does not seem fitting to stop with substances com monly known as dusts and thus fail to consider those which shajt soncwo, mtnnuMo, kxcavation, and demolition usually exist as vapors. Drilling operations in all such activities afford opportunity It is a common fault to focus attention upon one object to for dust generation. Again, the exposure depends upon the such an extent that others of equal importance are thereby rele type of rock encountered. Transportation of materials to and gated to obscurity. For the present, pneumonoconiosis, or horn the face or working area also allows dust to be distributed. more particularly silicosis, occupies the center of the stage and Steam-shovel work in excavations exposes workers to dust possibly for the purpose of this meeting such importance is clouds. In demolition work, the palling of walls, the dropping justified. However, the engineer interested in the control of of floors, the loading and unloading of debris causes the genera occupational disease by plant equipment and operation must not tion of much dust. Blasting operations when required not forget that there are many occupational diseases produced only generate dust through the action of the explosive itself, through exposure to industrial dusts other than silica-bearing but may precipitate other settled dusts by the shock transmitted ones and to vapors, and that the control of these industrial to the surrounding structures or areas. diseases may be brought about through the application of the fundamental principles which will be propounded by other stonx DaamiNO and fintskino speakers today. At present and until new avenues of control When this activity is in conjunction with quarry operations, are discovered, explored, proved, and utilised, the problem in the same quarry items previously listed pertain. Stone dress many instances seems aimostl acking a complete solution, but it ing and finishing is probably one of the meet prolific sources of is unquestionably true that certain occupational or industrial dust known. At least the exposure is one of the most serious diseases need not occur. The engineering aspects of their con due to the intimate personal contact of employees to the area trol are so well known that in the hands of capable plant of in which the dust is generated. Stone dressing promotes much ficials there can be little excuse for their occurrence. In the hand-tool labor. control of such diseases, industry today faces a problem, the Surfacing work, both hand and machine, produces quantities solution of which rests in the hands of the scientist, the physi of fine dust. Sawing, cutting, and channeling, as well as drill cian, and the engineer. ing, are also prolific sources of contamination. Hand chisel 'While the generation of dust in various types of industries ing produces a certain amount of fine dust but in chis work the > a more or lew common mode of origin, namely, the produc- larger particle sizes usually predominate. Hand polishing pro of finely divided material, yet it does not seem fitting to duces some dust but only a very small quantity as compared to ->up industries together even though the operations producing a mechanical polishing mill or jack. Even when wet polishing dust are somewhat similar. Therefore, in this paper, opera- is done, the quantity of dust it only slightly reduced. Sand will be discussed as individuaT to a general industry blasting operations, if not isolated, are dust producers. Such than as individual unto themselves and assigned to many dust generation it cumulative, as the abrasive material is broken names. While this may produce some repetition of ma- and forms a dust in conjunction with the material which is be yet for the sake of those engineers who are especially ing blasted and eroded. . in an individual industry, I feel the paper will have In addition to the operations indicated, workers themselves ! value. create a dost hazard by the blowing, by means of a compressed- quauT onaanoMS air nozzle, of dust which has accumulated around the tools or operations. . . Although the exposure in a quarry due to dust varies in ity based upon the chemical composition of the material aoxuniro aiAHUfO g quarried, most operations are similar. Drilling opera The cleaning of buildings by hand or machine may be con , both well and small-bore, produce voluminous quantities sidered a dusty operation. This is particularly true when sand small particles of the material in which the operations occnr. blasting either by air or steam is employed. The seriousness of Contributed by the Safety Committee sad presented at the Annual ' , December 3 to 7, 1934, of Tam Awseta Soaaxt os Ma> the hazard somewhat depends upon the type of material being cleaned. Naturally, rhn is additive with the dust from the Emob sand used for blasting purposes. 95 *? " 96 Mechanical Enginhbsxno ridual "" or u balk may produce dost. Spoil heaps "i<-- salted down may generate dust when the ordinary land breezes blow over than. ' comcutz nosocrt and A*nnciAD-roM* mamusactuuxo Mixing operations are dost producers in this type of in dustrial activity. Finishing operations if by sandblast or hand tools also produce dust. buck manusactuumq In the manufacture of brick as well as tile and terra cotta articles there are several sources of dust generation. The day-drying department, whether natural material is used or a mixed slip is used, produces dust when the dried materials are thrown into the air through handling. The dropping on the floors of small quantities of material allows it to become dry and then be dispersed in the air by workers walking or by transportation. Mixing opera tions give off dust. The operation of pug tnilli and brick molders may generate dust through the drying of the waste material. Storage departments may be a source of dust oc casioned through the handling of material. . BLntXMATIMO DUST IK aOCX DUXXIMQ (The drill operates through a dust collector cooaisang af s metal cap netted by a hose line to a taction tank and dost catcher.) MXNXMO The more common forms of mining are coal, feldspar, glass, sand, metals, mica, refractory materials, and calc. In any form of mining, dust is produced in the use of drills and exca vation machinery. This is true even in open-pit work. The exposure varies according to the rock encountered. As in other cases, the use of wet tools does not entirely eliminate the generation of dust. SAMS AMD QAAVSL DIOOIMO--7LZMT AMD*isAX imXJMXS These two operations are oftentimes associated. Underwater sand and gravel production is relatively noo-haxardous bat the sizing and screening operation, even though upon moist ma terial, may be a source of dust generation as the fine p--vwl-- will collect on machines, ledges, and parts of the buildings and later be swept into the air. When flint and spar milling is carried on cither in conjunction with sand and gravel digging or with any other source of taw stock, the hazard varies, as has been previously stated, accord ing to the composition of the material being Practi cally all operations are sources ofdust fwiwmiMfidii Primary crushers, either gyratory or jaw, produce dust; secondary crushers, screens, jigs, air separators, conveyers, and ocher types of machinery generally produce dust in air to a greater or less extent. Bagging, packaging, and shipping either as iodi- cxmxnt and uki mamusacxobiko When operating in conjunction with a quany or mine, previous sources of dust listed under such headings apply. In addition, all crushing operations produce dust. The charging operations to burners either hand or mechani cally done will create dust. The operations of the finish ing and packing department where bags and barrels are packed, dosed, crated, and shipped are a source of dust generation. souMimms The exposure to dust in foundry operations varies only slightly according to the type of foundry. A non-ferrous foundry may be link if any different on an overall exposure from a ferrous foundry. Sand-condition ing operations produce dust. The use of sand cutters or blenders, screens, riddles, tlingers, grab backets, and other conditioning machinery or operations may create dust. In molding processes the general work on the molding floor or the use of sand throwing and blowing machines may produce a hazard. The application of parting^compounds to the mold may create a dust. This situation is naturally more serious when the patting material used is of high free-silioa CODtBOC* Shake-out procedure, rattling and tumbling with or without air, sand-blasting, grinding, and snagging are dust-producing operations. Scratch-brushing work may generate dust. As previously mentioned, sand-blasting generates dust under any Charging operations in a cupola or any other type of furnace may generate dust iirthe immediate vicinity and biter coctaminatt the remainder of the premises. The storage of raw stock, such as limestone, coal, sand, and pig stock, may through generate additional dust. In addition to the exposures enumerated under mining and ate production, these exist in dm refining oprrsrion dusty aposures. Furnace operations, such aakharginfaad drawing, generate dust. This is particularly true when all or ponJona of the charging material constar of scrap, such as storage-bat tery plate*. Trucking of such may strew the fine material an the ground or floors where it may be picked up and thrown into the air by walking or by the wind. Skimming, rehearing, sad Fbmuas.t, 1935 stapling operations produce dose. The handling of the material in bag honaea, fines, or Cottrell pre- npmr may create a dotty exposure which it parties* larly serious during the cleaning operations neceswy to keep Cottrell precipitators or bag houses operating at props efficiency. The transportation ofmaterials in leaky containers, non-enclosed mechanical conveyers, or un covered cars creates a hazard. Hand shoveling may pro* dace dust in serious quantities. lootcoaT, znrc, and coma uromro The items enumerated under lead refining apply here also. In the production of zinc, one added exposure ap pears which is the dust produced in the blowing out of re tort condensers, either by barring down or by "shooting" the condenser with a slug of water. BATTSET UANOSACTOUNQ--SXOtAQB AND PBZXAET In the manufacture of storage batteries an exposure to dust exists in the preparation department. The handling, weighing, and mixing of the lead oxides either by hand or machine generates dust. In the pasting operations, either hand or machine, the material may be spilled upon the machine or the floor, become dried, and later be thrown into the air in the form of dust. The brushing of pasted grids will generate dust in a like manner. On the assem bly line even when only hand operations are in progress, dust may be generated. In the manufacture of primary batteries not only may dust be generated by mctal-cssting operations, but also ' in mixing, filling, and sealing. OEDOCAL MANUTACTOUNO It would be impractical to attempt to list all the opera* ; in chemical manufacturing which may be dust pro . Here again the seriousness of the exposure de- upon the material handled and the amount of *mmM. K. T. aterial that is thrown into the air. Chemical dura, rly tome dye and dye intermediates, are posi- sources of dermatitis where the dust generated lodges the skin of employees. It is sufficient to say that i are generated in the chemical industry and each in- aOCX DULL MOtTNTSD ON IUMO AND sqUlWlD WITS DBVK3 SOX TO BtnCNATlON OS SILICA DOST (The. bottles shown on the tripod measure the amount of silica which would be inhaled by the drill operator.) ridual operation requires study by itself, or machine, the packaging ofthe insecticides into baga, cartona, fin chromic-add manufacturing the sintering of ore is a dust- barrels, either by band or mechanically, and the transportation dudng job. The handling and transportation of the ore of materials from point to point in the plant generate dust in to the sintering either in furnace or kiln produces dust, varying degree. quenching of the sintered material may generate dust at i die crushing of the sintered stock. SAINT ANCOUtt MANUSACXUUNO Asaanros and Asaarros-oocos nanctactuuno The handling of bulk raw materials, as well as the grinding of filter-press cakes, will generate dost. Mixing and blending ' mining operations sad quarry operations are exposures, operations either wet or dry produce dust. This exposure is * * ' discussed. In the manufacture of asbestos goods, inherent in the handling of dry materials, hot the spillage of rly dusty atmospheres are created in the break-out, water-wet materials any dry oat and later be thrown into the and picking operations. The crushing sod grinding air. Batch weighing when the handling is by hand produces fiber, as well as all spaaing and weaving operations, dusty exposures. -' - l tendency to throw asbestos fiber into the sir sad create ! of dust wwimniMri/w Crushing and grinding asbes- lucts generates dust. The most hassrdous dussy sress is gfast aasufsctnring are msacnoDs kanttsactuaxnu *. ttoxicity of any dust generated in inarcTicidc manufactur- loested in the nw-aatckfeli receiving department and die batch-mixing df|nrratnr Use unloading of glass sand, soda ash, spar, flint, and odtinematerials from ban csss or trucks into according to the material being processed. There is storage bins producct dust^ - $ven when these materials are 7 of operations in most inarcTicidc manufacturing, mechanically handled, dust is generated. Batch mixing where arioo department, where the raw materials ate manu- "the various ingredients. asy^sfawai from stongc bins and ,, 1, involves dusty processes. The grinding of cakes ham weighed preparatory to being transported to the furnaces also r prases, the mixing of different ingredients, either by hand produces dust. ' 98 Mechanical Engineering POTTB1T MANUTACTUUINO Whit has been listed for glass manufacturing also applies to pottery manufacturing. This is true even when a slip system is used. In addition, the grinding and kiln-firing operations are important sources of dust contamination. ENAMELING AND ENAMBL-WAJLB MANUJACTUXINO In the preparation of enameling material by mixing, grind ing, in either bar or ball mill, blending, and solution-making dust is generated. Spray coating or dipping objects may cre ate a dusty atmosphere through the dispersion of the fine drop lets in air and drying out at the suspended material. The rim* ming of articles to produce stripes is a dusc producer of high severity. Loading kilns for firing including the operation of continuous tunnel kilns may produce dust in large quantities. In such manufacturing as well as in many others, the transport ing, storage, and handling of raw materials may be sources of dust. TKxnm This caption also includes paper, linoleum, felt, hair, and other similar types of manufacturing operations. Such dusts are not generally considered as being toxic, but yet a sufficient umber of instances have arisen to make it.appear warranted to include them within the scope of this paper. Picking, opening, mixing, blowing, carding, willowing, spinning, and other similar operations produce dust. In linoleum manufacturing the receiving of the raw filler material, such as soapstone, calc, and mica, as well as the storage of these materials and their handling during process work, may produce dusc. Both in hair and in hair-goods manufacturing, the dust may also in clude the spores of anthrax and the origin of such contamina tion may be particularly prevalent in the blowing and curling operations. MSTAUIC-POWDSX StANUVACTtTUINO Where a cupola is operated in connection with such opera tions, certain exposures previously listed may be found. In scamping the metal, dust may originate. In coating operations dust also occurs. Where an air-float method is used for che separation of fine particles from large, dust may be ex hausted into the atmosphere of che place of work in copious quantities. MISCELLANEOUS HXFOSUUS There are certain exposures where a material may exist in the form of a dusc, a vapor, or possibly a spray of fine droplets. The correction of any exposure of this type requires recognition on the part of the engineer of the material to which workers may be exposed and a determination of che point of origin of such material. A few miscellaneous exposures are discussed in the following paragraphs. Exposurt to Mtrturj. Exposures to mercury may occur in the mining of the ore, the reduction of the ore, and in the amalga mation of gold ores. Exposure is also found in xhe manufac ture of thermometers, Vermillion, and other dyes, the felt-hat industry, the treating and handling of furs; incandescentlamp, radio-tube, and other electrical-apparatus manufacture; explosives manufacture; and laboratory work, including photo graphic and research laboratories.. The exposure may be from the dust of the salts of mercury, the generation of fine droplets of mercury together with dusts of ocher nature, and the vapor of mercury which is generated at high temperature as well as small amounts which may be given off at ordinary room temperature. Esepoturt to Chromium. The exposure to chromium is usually found in the generation of the dust of the salts of chromium. There are certain processes in the manufacture of chromic acid and chromium salts from chromium ores which produce dust. The manufacture of paint pigments containing chromium, yarn dyeing and calico printing, the use of bichromates in dye prepa ration, the chrome process of leather tanning may also have dusty operations. In electroplating with chromium many fine droplets of chromic acid may be thrown into the air by the bubbles of hydrogen disengaging at the surface of the liquid in the electroplating tank. Exfotun to Btnzol. Exposure in the case of benzol is usu ally due to the vapor of the material. The operations of its production, its use in artificial-leather manufacture, in de greasing operations, and in others may result in an exposure. Information may be found in che report on benzol which was published several years ago by the National Safety Council. Exposurt to Ltsd. As lead is used in widely varied operations and in widely varied forms, it would be relatively impossible to list all of the operations which might include an exposure. The exposure usually exists in the form of dust of the material itself or its compounds or in che form of fumes which may be generated at points where the material is handled at tempera tures above its melting point. Dusty operations may occur in lead mining, lead refining, lead smelting and sintering, the manufacture of plumbers' supplies, foundries, battery manufacture, both storage and dry, pottery operations, glass manufacture, certain printing trades, rubber-tire manufacture, and paint manufacture. In addition, dusty exposures may occur in the chemical-manufacturing trades which involve the manufacture or use of lead or its compounds. Exposurt to Arsuite. Exposure to this material may often be found in the dusty operations surrounding the refining of copper ores and the manufacture of insecticides containing arsenic, either in the form of the oxide or other saits. Exposurt to Kadium and Radiosetht Substancts. The exposure to this material while not by any means general has been recog nized in isolated sections and attained for itself relative promi nence. The exposure may exist in the inhalation of dust from radium-bearing materials or the exposure to and the inhalation of emanations from radium. In general, this exposure is pro duced in the mining and handling of radium ore, the refining of the ore, the collection of radium emanation, and che use of the material in producing luminous dials for watches, clocks, and instruments. conclusion ' One should noc necessarily conclude that every operation listed in this paper is an absolutely dangerous source or point of origin of a toxic dust. It should noc be a foregone conclu sion that the operations listed in this paper include all of the possible sources of toxic dusts. The operations discussed, however, are typical of those where known cases of exposure have occurred. To the engineer unfamiliar with sources of air pollution, even in the so-called non-hazardous industries, the listing may seem far-fetched and ambiguous. It should not be assumed that an exposure listed in this paper is prims facie evi dence that trouble is inevitable, but to an engineer interested in protection against the more important sources of air con tamination by dust generation from ordinary industrial pro cedure, the listing will provide a basis upon which he may work. All in all, it is best for any engineer to proceed upon the basis that any dust of any type in any concentra tion creates an industrial exposure and to suppress the dust at its origin. AFFIDAVIT ACITY OF Umf-in. OHIO, TO WIT: BEFORE ME, A Notary Public in and for the State of Ohio, personally appeared fflienA AJfAL-, who stated under due oath of law as follows: I, ^^ . iam a librarian for the (name & address)'FZhJid.L'ibri.h'f a-f 6fiJ Ik-IH l/j~an {'odi^Y ^Ot) ^39.03. . The 'pLC^ Library contains copies of /Ag aUa/i it w l <Vi<i<lr/ y m a. (] tl >-t * The pages attached hereto are true and correct copies from UpldvruL. 7 a-mj\Js(omi Li e>-T liie.6 k& it < e^a\ r~7>,4 A10.J&.2 f h -.j I \3!b and 19 3*9,which is maintained in the This document is in such condition as to raise no suspicion concerning its authenticity. It was received on 193*1 by the ~H Library and is presently maintained in the I'l'la ^A. z<*.fL (V<L ut) Section of the (name and address). Pl 0 % D & j/i n c. _____Qi f__ OJL__ 4R 3l0'q- -0.0 *7 f & 7~ 04. t~- STATE OF OHIO COUNTY OF JlAshurv^ rflC 4/f^ , Affiant, being first duly sworn, deposes and says: That the foregoing statements are true and correct. S kJ 'V-enr* "0"