HX64076830 RA1231.L4 H184 Lead poisoning in th U. S. DEPARTMENT OF LABOR BUREAU OF LABOR STATISTICS ROYAL MEEKER, Commissioner BULLETIN OF THE UNITED STATES / iVffuni x: -.^^ BUREAU OF LABOR STgg^]gi^— \^ff°,^^l {Q^ INDUSTKIAX ACCIDENTS AHDHyciENF I^^TilTTrT^ LEAD POISONING IN THE MANUFACTURE OF STORAGE BATTERIES . DECEMBER 15, 1914 WASHINGTON GOVERNMENT PRINTING OFFICE 191S ^ii^ ^tii& :.^^ii5^gB5p|p^. T^Altv^/'l^ ///8^ COLLEGE OF PHYSICIANS AND SURGEONS LIBRARY Digitized by tine Internet Archive in 2010 with funding from Open Knowledge Commons http://www.archive.org/details/leadpoisoninginmOOhami U. S. DEPARTMENT OF LABOR BUREAU OF LABOR STATISTICS ROYAL MEEKER, Commissioner BULLETIN OF THE UNITED STATES* " (WHOLE 1/?C BUREAU OF LABOR STATISTICS^ ' ' ' i NUMBER 10 J INDUSTRIAL ACCIDENTS AND HYGIENE SERIES: No. 6 LEAD POI SON I NG I N THE MANUFACTURE OF STORAGE BATTERIES DECEMBER 15, 1914 \S7ASHINGTON GOVERNMENT PRINTING OFFICE 1915 COiNTENTS. Lead poisoning in the manufacture of storage batteries: Pago. Introduction 5-7 Processes in the making of storage batteries 7-16 Casting or molding - ' 7-9 Trimming grids 9, 10 Mixing the oxides for Faure plates 10 Making the paste 10, 11 Pasting plates - 11-13 Drying pasted plates 13 Forming or pickling 13, 14 Assembling and lead burning 14-16 Finishing 16 Hygienic conditions 16-19 Sanitary equipment 18 Medical care 19 "Wages, duration of employment, etc , 19, 20 Lead poisoning in the industry 20-32 Sources of information concerning the poisoning: 22, 23 Number of cases in five large factories 23-25 Type of lead poisoning 25-27 Lead poisoning in the industry in Great Britain and Germany 27-32 Summary , 32-34 Appendix A. — Regulations in Great Britain for the manufacture of electric accumulators 35-37 Appendix B. — General provisions of the French law governing th*^ man- ufacture of electric accumulators 38 LIST OF PHOTOGRAPHS. .Facing page — Plate 1. Casting room in large American factory 8 Plate 2. Casting grids by hand 9 Plate 3. Mixing lead oxides ' 10 Plate 4. Paste mixing by hand [Backing plate 3] Plate 5. Paste mixing by machine 11 Plate 6. Filling ironclads 13 Plate 7. Cleaning lugs and edges of pasted plates by machine vrith guards and exhaust 14 Plate 8. Cleaning lugsand edges of pasted plates without exhaust [Backing plate 7]. Plate 9. Assembling and cleaning [Following plate 8] Plate 10. Lead burning 15 Plate 11 . Charging room 16 3 BULLETIN OF THE U. S. BUREAU OF LABOR STATISTICS. WHOLE NO. 165. WASHINGTON. DECEMBER 15, 1914 LEAD POISONING IN THE MANUFACTURE OF STORAGE BATTERIES. BY ALICE HAMILTOX, M. A., M. D. INTRODUCTION. The making of storage batteries, or electric accumulators, as tliey are called in every country except our own, is increasing in extent and importance everyAvhere. It is regarded as a very dangerous lead trade. and the Governments of Great Britain and other Euro- pean countries have made strict regTilations as to the sanitation of places in which such work is done and as to the methods to be em- ployed in thencj^ since experience has shown that in the absence of regulations lead poisoning among the workers is a very serious evil. In the United States there are five large factories where storage batteries are made, one in Cleveland, Ohio; one in Depew, N. Y. ; one in Suspension Bridge, N. Y.; and two in Philadelphia, Pa. A great many smaller plants, employing from 5 to 15 men each, are scattered throughout the country, and many automobile factories -now have their own storage-battery departments. There are also estabhsh- ments where no new batteries are made but where old ones are reassembled and recharged. Railway companies usually have small plants for recharging the batteries used for train hghting. As a rule the smaller factories are rather neglected and dirty, more so than are the larger ones. The largest factory in the country has branches in several cities to which are shipped the plates ready for use- and these are then assembled into batteries in the branch estabhshments. A storage battery is described as a collection of secondary cells, or accumulators, which, when once charged by an electric current, may be used for some time as the source of electricity. The original type of storage battery, known as the Plante, consists of lead plates, which are usually corrugated or perforated to offer a larger surface for the chemical action of the charging current. The Faure cell was constructed with the purpose of hastening these 5 6 BULLETIN" OF THE BUREAU OF LABOE STATISTICS. cliemical changes. Faure plates are covered with a paste of lead oxides, the positive plate with red lead or a mixture of red lead and litharge (rarely with pure litharge) and the negative plate usually with litharge. Sometimes a Faure negative is paired with a Plante positive plate. Both Plante and Faure plates are ''formed" by the passage of an electric current, the effect of which is to change the metallic lead of the Plante positive plate and the lower oxides of the Faure positive plate to a higher oxide of lead, the brown peroxide, while at the same time the surface of the negative plate is reduced to spongy metallic lead. During the discharge of the electric cur- rent the reverse takes place, and a certain amount of lead sulphate is formed also, so that an old storage-battery plate is covered with a mixture of the sulphate and the lower oxides. For many years such cells were the only ones used for storage batteries, but of late the nickel-iron battery of Edison (the so-called alkaline battery) has been introduced and is said to be coming rapidly into general use. In this battery the positive plate consists of perforated steel tubes filled with nickel hydrate, the negative of perforated steel pockets filled with iron oxide. They are immersed in a bath of potassium hydroxide and charged, the nickel in the posi- tive plate being changed to black nickel oxide and the iron oxide of the negative to spongy iron. ' Edison batteries are, therefore, free from lead, but the Plante and Faure are lead batteries and their manufactuire involves the ex|)osure of workmen to the dangers of lead poisoning. There are many proc- esses in the making of these batteries which are attended with the formation of lead fumes or metallic lead dust or lead oxide dust and in which the workman's hands and clothes become covered with these' substances. First, there is the casting or molding of the ''grid,"j or plate, from molten lead which has usually a small percentage of antimony added. For Plante cells the grid is cast m ridges and furrows, or it may have roughened markings on the surface, or spaces filled with rosettes of lead ribbon. Faure grids are made in such shape as to hold large quantities of lead oxide paste. The gxid v/hen it comes from the mold is straightened and the irregular edges are trimmed smooth by hand or by machine. Then the grids for the Faure batteries must be covered with paste, and for this pur- pose red lead and litharge are weighed and mixed dry and then worked up with a hquid, usually dilute sulphuric acid. This also may be done either mechanically or by hand. The resulting paste is rubbed and pressed into the interstices of the leaden grids and the pasted plates are dried, assembled in pairs of positive and negative, unmersed in dilute sulphuric acid, and subjected to the action of an electric current. This is known as "foi-mmg," and the formed LEAD POISOiSrils^G IIST MAXUFACTUEE OF STOEAGE BATTEEIES. 7 plates are then washed clean of acid, dried, and made up into battery cells. To do this the pairs of plates must be assembled into large or small groups and bound together by means of pure lead which is melted with an oxyhydrogen flame, a process called lead burning. Then another electric current is passed through the cells to ''charge" them, and finally the men known as the "finishers" place them in receptacles of acid and fasten on the outer connectors with pure molten lead. This is a general description of the work in a storage-battery fac- tory, but it will be necessary to take it up more in detail, for there are many ways of carrying out the different processes, some of which are more dangerous than others. In the following sections the proc- esses are given in their logical sequence, not in the order of then* occurrence as one passes from room to room in any one factory. Often in the smaller plants all the work is carried on in one room, but in the five largest the dift'erent steps are separated to a certain extent. Forming and charging are always done in special rooms in these larger factories; weighing and mixing oxides and compounding paste are usually separated from the rest of the work; this is some- times true of pasting; and casting and trimming the grids and assembling and lead burning the plates are generally carried on in one or more large rooms, together with the making of Plant e plates and the final "fijiishing." PROCESSES IN THE MAKING OF STORAGE BATTERIES. CASTING OR MOLDING. There has been a good deal of controversy, especially among the Germans, over the presence of lead fumes in the air around the casting kettle of a storage-battery plant. Wutzdorf ^ holds that fumes escape in the course of the work of casting grids even when the lead is not much above 450° C. (842° F.). Wagener - also beheves that fumes arise from the melting pot, and he calls attention to the appearance of blue clouds whenever the workman stirs the contents of the pot. The tests made by the factory inspectors* in the Hagen factory, where the kettles are furnished with hoods, showed that even with that protec- tion lead escaped into the air, for clamp filter paper suspended above the casting benches showed the presence of particles of lead. British factory inspectors assume that there may be an escape of fumes from any molten lead which is exposed to the air, and they insist on precau- tions being taken accordingly. In American factories the lead used in casting is supposed to be decidedly below the fuming point, but if one watches the work of a 1 Arbeiten aus dem kaiserlichen Gesundheitsamte, 1S98, vol. 15, pp. 154-170. 2 Deutsche VierteljahrsscTirift fui- affentliche Gesundheitspflege, 1902, vol. 34, pp. 529-578. 8 BULLETIN OF THE BUEEAU OF LABOR STATISTICS. molder one can see that thougli there are no visible fumes as long as the lead is undistui'bed there are quite perceptible bluish fumes when the dross is skimmed or the lead ladled out. These fumes are in all probability the lowei oxides of lead in a state of very fme division and are therefore very poisonous. The analyses of air made for the New York Factory Investigating Commission ^ by Dr. C. T. Graham Kogers and John Vogt, B. S., shov\^ that in the storage-battery fac- tories in that State there is sometimes lead in the air around the molting pot. They found 3.4 milligrams of lead in 1 cubic meter of air in the casting room of a plant which had no exhaust over the pots and 1 milligram in a second place where the kettles were weU hooded. As an adult breathes about 4.5 cubic meters of air (hiring 10 hours, this would indicate that a man in the first factory might breathe 15.3 milligrams of lead during his day's work and a man in the second 4.5 milligrams, 25i'ovided this contamination of the air were constant and not accidental. In that case a man employed in the casting room of the first factory would run serious risk of lead poison- ing, if it is true, as Teleky says,- that a daily dose of 10 milligrams for several weeks may lead to severe acute poisoning. The molder stands close to the kettle, skimming dross and ladling lea'd into the molds. The dross he usually throws on the floor beside the kettle and walks to and fro over it as he works, grinding some of it into dust, which contaminates the air. The accompanying illustrations show how conditions may vary between casting rooms. The first (pi. 1) represents a casting room in one of the five large factories visited. The kettles are hooded, the hoods being connected with flues which carry off the fumes from the molten lead. The floor is reasonably clean, and the room dis- plays an evident intention to reduce the inevitable dangers of the work to a minimum. In the second (pi. 2) conditions are much less satisfactory. The kettle is unhooded, the open window beside it being relied upon to carry off the fumes. The dross and lead scraps on the floor are much in evidence. It is easy to see hoM^- as the men go about their work this lead refuse, is ground iato the wooden flooring until cleaning the latter m any satisfactory fashion is a practical impossibility. The danger in the casting room is in proportion to the number of kettles, the presence or absence of hoods with exhausts over the kettles, the degree of care which is used in handling the dross, and the separation of this work from other dangerous processes, for, in many factories, pasted plates are handled in this room and the dust of the dry oxide paste is thus added to the metalhc dust. Work in the casting room is sometimes made very disagreeable by the 1 Second report of the New York State Factory Investigating Commission, vol. 2, pp. 1129 and 1131. 2 Protokoll der Sitzung des grossen Rates deslnstitutsfiir Gevrerheliygicne, 1912, A. Seydel, Berlin, p. 1.5. LEAD POISONI^^G IN MANUFACTUEE OF STORAGE BATTERIES. 9 methods used in preparing the molds to receive the molten lead. For instance, in one plant visited the molds are dusted with very finely ground soapstone, used in such quantities that the room looks hke a flour mill, while the men are powdered like millers. In another jets of smoky acetylene gas are passed over the molds till a layer of carbon has formed, and the result is an atmosphere black with smoke. Wutzdorf ^ draws attention to the danger of arsenic in the fumes from the melting pots in the casting room, for the lead that is used may contain an appreciable quantity of arsenic. He quotes some analyses made by Fischer,^ which show that the arsenic present in hard or antimonial lead may run from 0.16 to 7.9 per cent. A smelting expert in the United States is authority for the statement that no antimonial lead in this country is quite free from arsenic. TRIMMING GRIDS. For convenience in handling, grids are often cast in pairs and then sawn apart by a machine which may have no protection or may be furnished with a glass or celluloid screen to keep the particles fiom flying in the workman's face. The edge of the grid must be smoothed and the superfluous lead cut or filed away, either by hand or machinery. In some places this work is very slight in amount, but in others there is a great deal of it. For instance, one plant was visited in which 16 boys were trimming edges with big knives, while in another plant almost as large, there were only two hand trimmers; the rest of the work was done by machinery and, since the grids were cast with clean edges, not much of it was necessary. There is a handle on the grid which projects from the battery and forms part of the connecting system, the leaden connectors being fastened on here. This is called the ''lug," and in the case of small grids the lug is cast in one piece with the body of the grid, but in the case of large grids it must be burned on to the body. The work of lug burning is also done in the casting room. The casting of Plante plates differs somew^hat from the method just described. Usually lead from a large kettle is run into a great flat moid and the resulting thick sheet of pure lead is rolled out by machinery tiU it is ^ery thm. Plates are cut from this sheet and ridges and furrows are then cut into them by machinery. This is called ''spinning" or "swedging" and is done with an abundance of oil or water to keep down the heat; incidentally the dust also is kept down. Another common, variety of Plante plate is the Manchester,. which consists of a frame of antimonial lead with interstices into which rosettes of lead ribbon are pressed. 1 Arbeiten aus dem kaiserlichen Gesundheitsamte, 1S9S, vol. 15, pp. 160-161. 2 See Ilandbueh der chemisehen Technologie, von Dr. Ferdinand FLsc^ier, Leipzig, 1893, S. 272. 10 BULLETIN OF THE BUREAU OF LABOR STATISTICS. The men wlio handle the Plante plates are exposed to oxide dust to a certam extent after the plate has been formed. MIXING THE OXIDES FOR FAURE PLATES. Up to this point the workmen have been exposed only to metallic dust and possibly to fumes from the kettles, provided the processes described have been carried on in rooms separate from those in which operations involving the making or handling of paste or pasted plates are performed. The trimmed grids for Faure cells must next be covered with a paste, the composition of which is a trade secret, but the essential elements of which arc the oxides of lead. It is generally said that dilute suli:)huric acid is used for moistening the oxides, but some paste rooms reek with ammonia fumes, showing that ammonia may enter into the composition of the paste. Usually, mixing the dry oxides for the paste is done with some pre- caution against dust. Plate 3 is an illustration of the mixing of oxides by hand without precautions. In one plant the weighing, dumping, and mixing all go on under cover and are controlled by a workman who stands outside the inclosuro and works through a window in the waU. In another of the larger plants there is a similar method of dumping the oxides under cover, but it is so carelessly managed that though the room is new and the mixer weU covered, the place is full of oxide dust. In a third the work is done in the open but carefully and with exhausts over scales and mixers, so that the room is very clean. In a fourth large plant the mixing is carried on at one end of the pasting room. There is no exhaust over scales or mixer and the litharge or red lead is simply scooped up from the kegs and dropped into the scales, which are then emptied into the mixer. At the time this place was visited a worlonan was engaged in mixing oxides, and clouds of yellow dust were perceptible. In one of the smaller plants also the oxides were being weighed on unprotected scales and mLxed in an open chaser directly beside the pasj:ing table. The accompanying illustration (pi. 4) shows the process of mixing paste by hand. The mixmg takes place under glass cabinets con- nected with a large flue, the exhaust in which is supposed to carry off the dust. Nevertheless a coating of dust is plainly visible on the platform on which the mixers stand and on the benches and utensils near them. MAKING THE PASTE. By far the safest way is to have all the paste made up in a special room and given to the men who then apply it to the grids. Id this way only a few men come in contact with the dry oxides. This method is followed in three of the five largest plants, but in the other PLATE 3.— MIXING LEAD OXIDES. Tho v/ork is done partly by hand, partly in a primitive, churn-like machine. There is no device tcr^rcmoval of the dust which is formed in weighing, in filling the mixer, and in emptyingthe PLATE 5.— PASTE MIXING BY MACHINE WITH DUST-PROOF FUNNEL. The oxides are admitted from an overhead bin and mixed without necessitating opening the machine. LEAD POISOXIXG 11^ MAXUFACTUEE OF STORAGE BATTESIES. 11 two the dry oxides are made into paste in the pasting room. In one of the latter four or six men make up the powder into paste by hand^ working at a table with a glass case and an exhaust. At the time this place was visited the floor near the paste-mixing table was covered thickly with scarlet dust and the mixers' overalls and shoes were scarlet. Three cases of lead poisoning were found which had been contracted at this table during 1913. The dust is also a menace to the pasters who work in the same room. The other plant has an even worse method, for here the dry oxides are weighed in open scales in quantities for the pasters, each of whom must make up his own paste. There are no exhausts at these pasting tables. In the three plants where the paste is made for the men, paste mixing is done in a special room. Bread-kneading machines are used for this purpose in one (see pi. 5), and in another the paste is mixed in large mortars beside each of which is an exhaust. Neither of these plants is above criticism in the conduct of this part of the work, for the rooms are far dustier than they should be and one is in an ex- tremely neglected condition. The third plant has a fahly clean mixing room with a cement floor which can be flushed with water, but the man who makes the litharge paste has a dangerous habit of throwing handfuls of dry litharge over the tray which is waiting for the paste, as a baker would flour a pan to keep the dough from sticking. Wagener ^ says that when the making of paste and the pasting of plates were carried on in the same room in the Hagen factory, 20 out of 27 men in that room had lead poisoning, but a,fter the two processes were separated only 10 out of the same number were poisoned. He also gives the results of certam changes in a Cologne factory, where, in addition to separating the pasting from the mixing, the pasting tables were furnished with glass cabinets and exhausts, this being necessary because the pasters sometimes had to add dry oxide to the paste. Before the introduction of these protective measures there were 37 cases of lead poisoning among 153 pasters; afterwards there were 9 among 194, and the following year, only 8 among 209. PASTING PLATES. Pasters v/ork at tables which may be covered with glass and fur- nished v/ith" projecting wooden rims, or of wood with a glass plate laid on it, or simply of wood with no glass. Of course, glass is by far the best because it can easily be cleaned at the end of the day's work, while wood becomes impregnated with the oxides and can not be scrubbed clean. It is desirable to have a raised rim around the edge of the table to keep the paste from dropping on the floor. There is a great difference in the pastes used in the different plants, and the same plant may use several kinds. Sometimes the paste is 1 Dentscbe Viertel jatosschrift f iir oflentliche Gesandheitspflfige, 1902, vol . 34, p. 550. 12 BULLETIN OF TPIE BUREAU OF LABOR STATISTICS. decidedly moist a,nd takes some time to diy and become dusty; again, it may be so dry as to crumble. There are pasters who wear leather or rubber gloves and use wooden spatulas to rub the paste into the grid; but the majority wear no gloves and many Ivnead the paste with their fingers. It is doubtful whether gloves afford much pro- tection, for so many men have a habit of taking them off and then putting them on again over dhty hands. In three large plants the pasting tables are furnished with an exhaust system, though in one of the three this is installed only at the tables for red lead paste, not for the litharge. The arrangement con- sists in an opening, wide or narrow, along the far edge of the table opposite the paster or along the right-hand edge, with a board pro- jectmg over it and an exhaust behind it. Such an exhaust is of very doubtful value, as the wet paste on the table is not in itself a source of danger. In no case was it possible to see any dust arising from the paste which was under manipulation. The danger comes from the paste that has fallen and dried on the edges of the table, on the floor, and on the men's clothes, and the exhaust can not catch up dust from these places. Pasting rooms are always scarlet and yellow from red lead and Utharge dust, though they are supposed to be cleaned every night. The part of the room devoted to litharge paste never looks as dusty as the part devoted to red lead, because the latter is such a vivid color, while litharge is about the color of wood and does not show on tables and floors. One supermtendent, how- ever, said that he had more trouble with lead poisoning from the litharge paste than from the red lead; he thought it was dustier when it dried than red lead. Rogers and Vogt^ found in one pastmg room, just over the table, 4.2 milligrams of lead in a cubic meter of air, and in a second 1.2 milligrams. These quantities mdicate that in the first factory it might be possible for a man to breathe in, during the day's work, 18.9 milligrams, and in the second 5.4 milUgrams. The dust in the pasting room is increased where the men are allowed to throw on the floor strips of paper covered with paste; these soon dry, and as the men walk back and forth over them the dry paste is ground into dust. This is seen in factories where the process of drying the plates is hastened by pressing strips of paper on them much as one would use a blotting paper. These papers must be pulled off and then, covered with oxides as they are, they are sometimes thrown on the fl_oor to be gathered up at the end of the day. In two plants, however, they are dropped into receptacles so that they do not spread the dust as they dry. One kind of plate is known as the ''ironclad." This is a light grid made of slender parallel rods of metal over each of which is 1 Second Report of the New York State Factor}- Investigating Commission, vol. 2, pp. ll:?9 and 1131. LEAD POISONING IN MANUFACTUEE OF STORAGE BATTEEIES. 13 slipped a very loosely fitting rubber tube with narrow openings in its circumference. The grid is placed upright on a table uncier a glass case and dry red lead is forced into the spaces between the rubber tubes and the rods, the grid bemg violently shaken all the time to shake the red lead down. It is an extremely dusty process and in spite of the protection of the glass case, there were heaps of dust all around the place in the one plant in which these plates are made (see pi. 6). One man working at the machme for filling these grids had his face powdered with red lead and the red color could be seen in his nostrils. The full grid is taken to another table which also is provided with a glass case, is place.d m a frame, and the end is fitted on, and the connectors burned. This second table was of wood, with wide cracks, and there were quantities of dust over it and over the floor. From this table the plates go to the acid tank. DRYING PASTED PLATES. The pasted plates, if they are small, may go at once to the tanks in the ''forming" or ''pickling" room, but large ones are usually dried first because the acid in the pickhng trough penetrates more quickly if the paste is dry. This drying is done either in a separate room or on racks in the pasting room. When the plates are dry their surface has set Hke cement and is hard and firm, yet they can not be handled without raising dust, the shelves on wliich they rest are always covered with dust, and the men who take them ofi^ the racks and carry them to the assembling room have a very dusty piece of work. When, as is often the case, the drying cabinets are in the paste room, this makes another source of air contamination in that room. FORMING OR PICKLING. The forming room is large and usually well ventilated, filled with long troughs of dilute sulphuric acid in which are immersed large numbers of plates, connected by a copper bar. A current of elec- tricity is sent through the plates, and when they are taken out they have been "formed" and the positive one is covered with a coating of the brown peroxide, the negative with gray, spongy lead. In the forming room and, to a slighter extent, in the charging room where a second treatment with an electric current takes place, the fumes of sulphuric acid are strong enough to cause much discomfort to a person not accustomed to them. Nevertheless the men working there do not seem to experience any irritating efl'ect upon the eyes and throat, and German factory inspectors say that physicians find no increase in lung trouble or in inflammation of the eyes among these men. Chyzer,^ how^ever, after an examination of some Aus- 1 Annales d'hygiene publique et de medecine legale, 1908, 4th series, Vol. X, pp. 239-260.. 14 BULLETIN OF THE BUEEAU QF LABOE STATISTICS. trian factories gained quite a difTereiit impression, and in order to decide the question lie subjected rabbits to an atmosphere similar to that in forming rooms. He found that there was enough sul- phuric acid in such air to cause bronchitis and even foci of inflam- mation in the lung tissue of animals. The bubbles which are always rising from the acid troughs carry with them tiny drops of acid, and Chyzer found, in a forming room with open wmdows, a deposit af 1.28 grams of sulphuric acid on one square meter of surface. In a room with closed windows the cpantity on a surface of this extent was 3.97 grams. The workmen, he found, often suffered from bron- chitis and nosebleed and the acid fumes also exerted an injurious effect on the enamel of the teeth. On the other hand, Bottrich, one of the physicians to the Hagen factory, behev-es that these acid fumes are actually beneficial. None of the physicians interviewed in the course of the present study had noticed any ailment among the men traceable to their occupation in the forming room. When the formed plates are taken from, the acid, they are washed and soaked in various solutions, the composition of which is f.lways a trade secret, but the work is of no apparent importance from the writer's point of view. ASSEMBLING AND LEAD BLTRNING. Tlie dusty processes begin again in the assembling room where the formed plates are grouped and fastened together by lead strips. A group of positive plates is then fitted together with a group of negatives and between each pair of plates is shpped a thin strip of wood. This work is known as assembling and the men as assem- blers. Lead burning consists in fasterdng the groups together and connecting positive and negative groups by a soldering process in wliich pure lead is used instead of ordinary solder,- and the heat is apphed by means of an oxyhydrogen flame. This is done in the same room as the assembhng and the two &re often spoken of together as assembhng, or the work of the whole department may be designated as lead burning. This makes it difficult to find out exactly what Idnd of work was done by a man employed in such a room. Other occupations are frequently carried on in the assembhng rooms, such as the inspection of formed plates before they go to the assemblers, the imperfect ones being rejected, or straightened, trimmed, and filed. Small plates wliich have been pasted in pairs are sawn apart in tliis room and both the trimming and sawing are productive of a great deal of dust because the plates are now covered with diy oxides. The cleaning of the edges and the lugs of pasted plates is another dusty piece of work usually carried on here. The projecting part of the plate, known as the lug. and the edges of the plate have, PLATE 8.— CLEANING LUGS AND EDGES OF PASTE PLATES WITHOUT ANY EXHAUST. LEAD POISOinNG IN MAiS^UFACTUKE OF STORAGE BATTERIES. 15 ill the process of pasting, become more or less smeared with paste and in order that good connections may be made this dried oxide must be cleaned off and the metal brushed and scraped till it is bright. The work may be done by hand or by machine. The accompanying illustrations (pis. 7, 8, and 9) show the oper- ations of cleaning and assembHng. The machine shown in plate 7 is carefully equipped to reduce the danger to the worker as much as possible. In spite of the exhaust, however, an accumulation of dust and bits of paste is seen beneath the machine. Plate 8 shows the method of cleaning plates by hand, in which the worker has either no i^rotection at all or only such as is given by a respirator. Plate 9 shows conditions when, as is often the case, cleaning and assembling are carried on in the same room. The assemblers proper handle dry oxide plates, but not in such a way as to cause the production of much dust. The lead burnei-s have work which German and English authorities consider particu- larly dangerous. They use a small but very hot oxyhydrogen flame to melt a narrow bar of pure lead (see pi. 10). The question is how much volatihzation of lead is caused by the tiny flame. As we shall see later, the most recent British reports show more lead poisoning among the lead burners than among any other workmen in the electric accumulator factories, and British factory inspectors are advising the installation of air exhausts at the work benches to protect these men. The German factory inspectors also report a rate of lead poisoning among burners in certain factories even higher than that among pasters, and they have shown by means of pieces of moist filter paper suspended above the lead burner that lead passes into the air.^ Roth, however, questions the interpretation of these tests. He repeated them and found that when the workman was engaged only in lead burning there was no appreciable lead caught on the filter paper, but when, after bm-ning, the man proceeded to polish the surface of the lead with a steel brush, there was a distinct deposit of lead dust on the paper.^ In the United States the lead-burning department has a much better reputation among physicians and workmen than has the mixing or pasting department,, and very few cases of lead poisoning cduld be traced to it in the plants visited. It may be that we have so much more sickness in our pasting and mixing rooms that the less dangerous departments are overshadowed. Another explana- tion was offered by an expert familiar with the industry in England as well as in this country. He said that the Enghsh use in lead 1 Jahresbericht des Regierungs- und Gewerberates fiir die Regierungsbezirk Armljerg pro 1S96. = neitrage zur pathologischn Anatomic und allgemeinen Pathologie VII Supplement 1905, S. 1S4-197. 16 BULLETIN OF THE BUEEAU OF LABOR STATISTICS. j bui-ning a pure oxyliydrogen flame, while the Americans use hydrogen mixed with atmospheric air in which the oxygen is greatly diluted. The pure oxygen makes a much hotter flame and therefore causes more volatihzation of lead. The source of lead dust noted by Roth, \ the pohshing of the hardened lead ^vith a steel brush, was not seen in any lead-burning room visited in the course of this inquiry. Eogers and Vogt were able to demonstrate in one factory 2.6 milli- grams of lead per cubic meter in the air over a lead burner's bench, and 1.8 grams in another,^ but in view of the many dust- producing processes which are carried on in those assembhng rooms, it is impossible to estimate how much of the lead represented vola- tilized oxides and how much dust. FINISHING. This term is a little confusing, for it is used bot-h for the trimming and polishing of grids in the casting room and for the final making up of batteries. In this report it is used in the latter sense only. The plates wdiich have been assembled and burned together, go next to the charging room for the passage of the second electric current. The accompanj'ing illustration (pi. 11) shows the method of charging. The room in wliich this oj)eration is carried on is like the forming room except that the acid fumes are less strong. The plates are then brought to the finishers who place them in ceUs filled with acid and fasten on the covers and the outer connectors, thus making up the batteries. The only lead work here is making the coim.ectors on the outside of the battery. This is essentially the same as lead burning, for it is done ^vith pure lead and the oxy- hj'drogen flame. Small plates are placed in hard-rubber containers, medium-sized ones in glass and large ones in wooden boxes lined with sheet lead. The making of these lead-hned containers is similar to lead burning, the edges of the lead sheets being welded together by the oxyhydro- gen flame. It maj^ be done in the assembling room or in the room for casting Plante plates. One foreman called attention to the fact that in making the largest of these containers, the bm^ner was obhged to put his head inside it or he would not be able to make accurate joinings, and of com'se the sHghtest leak would spoil the battery. If there reaUy are fumes produced in such lead burning, the workman can not avoid inhaling them. HYGIENIC CONDITIONS. An inspection of the storage-battery establishments in this coun- tiy gives one the impression that only lately have the employers awakened to the dangerous character of the work they have been 1 Second Report of the Xe-.v York State Factorj- Investigating Commission, 1913, vol. 2, pp. 1130, 1131. "^ — ■'-' C3 ^> O f^ c3 id., p. 201. Annual Report of the Inspector of Factories, 1912, p. 205. LEAD POISOXIXG IX MAjSTUrACTUEE OF STOEAGE BATTEEIES. 31 It is easy to see from this report why the dangers of lead buriiino^ and finishing were so apparent to the inspectors. The process of ptisting and of mixing the paste, which with lis is the most dangerous of all, has been well controlled in England and docs not cause nearly as much trouble as the comparatiyely safer work of lead burning. In 1910 visits were paid to two large accumulator factories in the city of London. As the vigilance of the factory inspectors has brought about various improvements during the last four years in British factories of this l-dnd, it is probable that some of the featm-es which were noted at the time of these visits as being open to criticism have since been corrected. On the whole even in 1910 conditions were superior in these factories to those in our own, chiefly because of better supervision of the men at work, greater personal care of the employees, and better housekeeping. We shaU mention only the most important features in these factories. The casting rooms had in both instances hooded kettles provided mth exhausts. In one the kettles were further protected by sliding panels of iron which could be open or closed according to the draft in the room. The surface of the lead in the kettles was covered with charcoal to prevent the -formation of skim or dross. The Home Ofiicc assumes that lead fumes or oxide dust ma}^ escape from molten lead no matter how low the temperature, and therefore insists on hoods for the kettles. In both factories the mixing rooms in which also the paste was made were quite separate; the floors were of cement, kept moist, and cleaned by flushing. The mixing was done under an exhaust draft in a closed machine, and the men at work wore respirators which in England consist of muslin bags tied over the mouth and nose. The scales on which the ingredients were weighed were also protected by a hood with an exhaust. In one factory 2 men were emploj^ed at mixing; in the other 14 took turns at it, 2 working at a time. Xeithor room was entirely dust free. The paste was given out to the pasters, who worked in a room in which no other process was carried on. These rooms were large with cement floor, kept continually wet. The pasters stood on boards to keep their feet dry. The workbejiches were covered with sheet lead and protected by a raised edge to keep the paste from falling to the floor. The men were furnished ^vith full suits of overalls, oilcloth or leather aprons, and heavy leather gloves. In both factories the drjdng room was open to criticism because of the fine dust on floors and sh-elves. It was said that they were flushed out once a week. In the forming rooms they had a way of drawing off the acid entirely before the plates were taken out, which added to the comfort of the workmen removing the plates. 32 BULLETIJ^r OF THE BUREAU OF LAEOK STATISTICS. Assembling and load burning were at tliat time carried on just as in American factories, with no special precautions against dust or fumes, because, as was explained by the factory inspector, these proc- esses were not supposed to be attended with, danger. As we have akeady noted, there has been a change of opinion since then and an effort is to be made to carry off the fumes and prevent the dust. As is usual in British factories, the lavatories in these two con- formed to the strict letter of the law, but were not luxurious. They were, however, entirely adequate. The men exposed to lead are required to take a bath once a week. There were large lunch rooms, p.nd no food might be kept or eaten in any other room, nor were any of the men allowed to enter the lunch room before taking off their overalls and washing. Medical inspection was monthly in one, every three weeks in the other. In the larger of the two factories, between 80 and 100 men came in contact with lead in castmg, mixing, pasting, and drying. There had been no case of lead poisoning discovered among them during the preceding year. Here, as in the German factory, a man engaged in lead work who seemed indisposed was given a job in the open air temporarily. This company sold tooth- brushes to the men at twopence halfpenny apiece, and if the man failed to use his toothbrush, if his teeth were persistently dirty, he was discharged. The British special rules for the making of electric accumulators are published in full in the appendix; essentially they are the same as the German.^ The German rate of lead j)oisoning in tliis industry, or rather that of the greatest German factory, is less than 1 per 100 men employed, and the British rate is about 3 per 100 employed. The rate in our five largest factories is almost 18 per 100 employed, and this great difference must be explamed by the neglect in this countiy of factory sanitation and of personal care of the men employed. No new legislation is needed to bring about reforms in this industry; the laws of Ohio, New York, and Pennsylvania are quite adequate. It is a c[uestion of adequate enforcenaent. SUMMARY. The ordinary storage batter}^, not the Edison, consists of plates of lead, or of lead grids covered with a lead oxide paste. In the prep- aration of these plates and grids the workmen are exposed to the 1 The French law of October 1, 1913, covers establishments in which storage batteries are manufactured. The regulations, which are given in the appendix, are similar to the German and British, but there is one specially good section which requires that men who apply for employment in an accumulator factory must bo examined hy a physician and that they can not continue to work without obtaining a second certificate of good health at the end of the fu-st month, and after that, at the end of every three months. The exam- ining physician is paid b}^ the company. LEAD POIS0Iv'I]N"G IN MAXUFACTUEE OF STOEAGE BATTERIES. 33 dtmger of lead poisoning through dust of metalHc lead and tlu'ough fumes from melted lead. In making and applying the paste the workmen are exposed to still greater danger of poisoning from the oxides of lead. The subsequent processes of assembhng, lead burning, etc., involve exposure to the fumes of melted lead and to the dust from dried oxide paste. These dangers can be obviated by installing hoods and exhausts to carry off fumes and dust, by substituting machine for hand work, by providing ample washing facilities for the workmen and insisting on strict cleanliness on their part, by providing a separate lunch room as the only place where food may be kept and eaten, and by keeping the premises where the work is carried on clean and free from dust. Inasmuch as some risk always remains after all possible precautions have been taken, there should be thorough medical supervision of the men in order to detect and eliminate those who are oversusceptible to lead, to discover cases in the early stages, and to give instractions to the men on the care of themselves. By using precautions such as these, German and British employei"s have greatly reduced the amount of lead poisoning in factories of this kind. In the largest German factory the rate of poisoning m 1912 was 0.97 per 100 employed, and in Great Britain the rate for all factories "during this same year was 3 per 100. In the United States the five largest factories were during 1913 employing about 915 men in work which exposed them to lead. It has been possible to discover 164 cases of lead poisoning which occurred among the employees of these plants m this one year. This makes a rate of 17.9 per 100 employed. The largest proportion of lead poisoning occurred among the men handling lead oxides, the lowest among those handling met^Uic lead only. The disease was usually typical acute lead poisoning, with gastric symptoms predominating, but even an acute attack often resulted in incapacitation from work lasting for several Aveeks to two months or over. Out of 40 cases 23 had marked nervous symptoms. Chronic plumbism was rarely found, since the men hardly ever remain long at the work. The employees in this industry in the United States are for the gi-eater part of foreigTi birth; many speak no English and are ignorant of the dangers of the work, or if they recognize the danger, do not know how to protect themselves against it. The difference between the American rate of lead poisoning and tlie British and German rates must be explained by the different standards of sanitation and management in this country as compared with those of European-countries. None of the five large factories in the United 73764°— Bull. 165—15 3 34 BULLETIX OF THE BUEEAU OF LABOE STATISTICS. States comes up to the British, or German estabhshments in cleanH- ness or in the removal of fumes and dust, and only one provides as careful medical supervision. Smaller factories in this country are even less well managed. The three States in which the five largest factories are situated have ahead y passed laws which cover this industry and provide safe- guards for the men engaged in it, and if these laws are strictly enforced by intelligent factory inspectors there is no reason why our record of lead poisoning should not fall, as it has fallen under intelhgent super- vision in Great Britain and Germany. APPENDIX A.— REGULATIONS IN GREAT BRITAIN FOR THE MANUFACTURE OF ELECTRIC ACCUMULATORS.^ Whereas the manufacture of electric accumulators lias been certified in pursuance of section 79 of the Factory and Workshop Act, 1901, to be dangerous; I hereby, in pursuance of the powers conferred on me by that act, make the following regulations, and direct that they shall apply to all factories and workshops or parts thereof in which electric accumulators are manufactured. In these regulations "lead process" means pasting, casting, lead burning, or any work involving contact with dry compounds of lead. Any approval given by the chief inspector of factories in pursuance of these regula- tions shall be given in writing, and may at any time be revoked by notice in writing signed by him. Duties of occupier . 1. Every room in which casting, pasting, or lead burning is carried on shall contain at least 500 cubic feet of air space for each person employed therein, and in computing this air space, no height above 14 feet shall be taken into account. These rooms and that in which the plates are formed shall be capable of thorough ventilation. They shall be pro\-ided with windows made to open. 2. Each of the following processes shall be carried on in such manner and under such conditions as to secure effectual separation fi'om one another and from any other process. (a) Manipulation of dry compounds of lead ; (6) Pasting; (c) Formation and lead burning necessarily carried on therewith; {d) Melting down of old plates. Provided, That manipulation of dry compounds of lead carried on as in regulation 5 (6) need not be separated from pasting. 3 . The floors of the rooms in which manipulation of dry compounds of lead or pasting is carried on shall be of cement or similar impervious material, and shall be kept con- stantly moist while work is being done. The floors of these rooms shall be washed with a hose pipe daily. 4 . Every melting pot shall be covered with a hood and shaft so arranged as to remove the fumes and hot air from the workrooms. Lead ashes and old plates shall be kept in receptacles .specially provided for the purpose. ■ 5. Manipulation of dry compounds of lead in the mixing of the paste or other pro- cesses shall not be done except (a) in an apparatus so closed or so arranged ^\T.th an exhaust draft as to prevent the escape of dust into the workroom; or (6) at a bench provided with (1) efficient exhaust draft and air guide so arranged as to draw the dust away from the worker, and (2) a grating on which each receptacle of the com- pound of lead in use at the time shall stand . 6. The benches at which pasting is done shall be covered with sheet lead or other imper\T.ous material, and shall have raised edges. 7. No woman, young person, or child shall be employed in the manipulation of dry compounds of lead or in pasting. 8. (a) A duly qualified medical practitioner (in these regulations refeired to as the "appointed surgeon") who may be the certifying surgeon, shall be appointed by the occupier, such appointment unless held by the certifj-ing surgeon to be subject to the approval of the chief inspector of factories. (6) Every person employed in a lead process shall be examined once a month by the appointed surgeon, who shall have power to suspend from employment in any lead process. (c) No person after such suspension shall be employed in a lead process without written sanction entered in the health register by the appointed surgeon. It shall be 1 Factory and workshop acts. Dangerous and unhealthy industries. Regulations and Special Rules in force on 1st January, 190S. London, 1907, p. 7. [Regulations, dated November 2i, 1903,made by the secretary of state for the manufacture of electric accumulators.] 35 36 BULLETIX OF THE BUEEAU OF LABOR STATISTICS. sufficient compliance vidth. this regulation for a written certificate to be given by the appointed surgeon and attached to the health register, such certificate to be replaced by a proper entry in the health register at the appointed surgeon's next -visit. (d) A health register in a form approved by the chief inspector of factories shall be kept, and shall contain a list of all persons employed in lead processes. The appointed surgeon will enter in the health register the dates and results of his examinations of the persons employed and particulars of any directions given by him. He shall on a pre- scribed form furnish to the chief inspector of factories on the 1st day of January in each year a list of the persons suspended by him during the previous year, the cause and duration of such suspension, and the number of examinations made. The health register shall be produced at any time when required by H. il. inspectors of factories or by the certifying surgeon or by the appointed surgeon. 9. Overalls shall be provided for all persons employed in manipulating dry com- pounds of lead or in pasting. The overalls shall be washed or renewed once cA-ery week. 10. The occupier shall provide and maintain — (a) A cloakroom In which workers can deposit clothing put off during working hours. Separate and suitable an'angements shall be made for the storage of the overalls requii-ed in regulation 9. (h) A dining room unless the factory is closed dming meal hours. 11. No person shall be allowed to introduce, keep, prepare, or partake of any food, drink, or tobacco, in any room in which a lead process is caiTied on. Suitable pro- visions shall be made for the deposit of food brought by the workers. This regulation shall not apply to any sanitary drink provided by the occupier and approved by the appointed surgeon. 12. The occupier shall provide and maintain for the use of the persons employed in lead processes a lavatory, with soap, nailbrushes, toAvels, and at least one lavatory basin for every five such persons. Each such basin shall be provided with a wa.'^te pipe, or the basins shall be placed on a trough fitted with a waste pipe. There shall be a constant supply of hot and cold Avater laid on to each basin. Or, in the place of basins the occupier shall provide and maintain troughs of enamel or similar smooth impervious material, in good repair, of a total length of 2 feet for every five persons employed, fitted withAvaste pipes, and without plugs, A\-ith a suffi- cient supply of Avarm water constantly aA-ailable. The lavatory shall be kept thoroughly cleansed and shall be supplied A\-ith a suffi- cient quantity of clean towels once every day. 13. Before each meal and before the end of the day's Avork, at least 10 minutes, in addition to the regular meal times, shall be alloAved for washing to each person AA^ho has been employed in the manipulation of dry compounds of lead or in pasting: Provided, That if the lavatory accommodation specially reserved for such persons exceeds that requh-ed by regulation 12, the time alloAvarice may be proportionately reduced, and that if there be one basin or 2 feet of trough for each such person this regulation shall not apply. 14. Sufficient bath accommodation shall be provided for all jiersons engaged in the manipulation of dry compounds of lead or in pasting, with hot and cold water laid on, and a sufficient supply of soap and toAvels. This rule shall not apply if in consideration of the special circumstances of any par- ticular case the chief inspector of factories approA-es the use of local public baths Avhen conveniently near, under the conditions (if any) named in such approval. 15. The floors and benches of each workroom shall be thoroughly cleansed daily, at a time when no other Avork is being earned on in the room. Duties of persons employed. 16. All persons employed in lead processes shall present themselves at the appointed times for examination by the appointed surgeon as pro Abided in regulation 8. No person after suspension shall work in a lead process, in any factory or Avorkshop in Avliich electric accumulators are manufactured, without Avritten sanction entered in the health register by the appointed surgeon. 17. Every person employed in the manipulation of dry compounds of lead or in pasting shall AA^ear the OA'eralls provided under regulation 9. The overalls, when not being worn, and clotliing put off dming working hours, shall be deposited in the places proAdded under regulation 10. 18. No person shall introduce, keep, prepare, or partake of any food, drink (other than any sanitaiy drink provided by the occupier and approA^ed by the appointed surgeon), or tobacco in any room in which a lead process is canied on. LEAD POISONIXG lis MAXUFACTUEE OF STOEAGE BATTEEIES. 37 19. No person employed in a lead process shall leave the premises or partake of raeals without previously and carefully cleaning and washing the hands. 20. Every person employed in the manipulation of dry compounds of lead rr in pasting shall take a bath at least once a week. 21 . No person shall in any way Interfere, without the concun-ence of the occupier or manager, with the means and appliances provided for the removal of the dust or fumes, and for the caixying out of these regulations. These regulations shall come into force on the 1st day of January, 1904. A. Akers-Douglas, One of His Majesty's Principal Sccreto.Tiies of State. IlOME Office, "Whitehall, £lst November, 1903. APPENDIX B.— GENERAL PROVISIONS OF THE FRENCH LAW GOVERNING THE MANUFACTURE OF ELECTRIC ACCUMU- LATORS.^ The kettles for melted lead must be kept in separate well-venti- lated rooms, and efficient air exhausts must be provided. Work with lead oxides must be done wet as far as possible. When this is not practicable, it must be carried on mechanically in a closed apparatus, or if the oxides must be handled, then the work must be done under a strong exhaust; if this is impossible, the workmen m.ust be given respirators. Mixing must be done in a sej^arate room. No dr}' oxides may be handled in rooms where other work is done. Oxides, dry or wet, must never be handled with bared hands. The employer must provide proper tools or impermeable gloves. The tables on which the paste is handled must be covered with impermeable material and kept in good condition. The floor must be of impermeable material and kej)t always damp. Tables, floor, and walls must he washed at least once a week. Overalls must be provided and maintained in good condition. No food is to be carried into the workroom. Separate dressmg and wash rooms must be provided with sufficient washing facilities, soap* one clean towel a week for each man, and a locker for each man's clothes; a weekly warm bath, tub or shower, must be provided. For specified workers a dailj' warm bath must be provided. Before employment a man must undergo a medical examination to show that he is not suffering from any disease which would make his employment in such work dangerous. At the end of the first month he must undergo a similar examination, and after that at three-month intervals. A medical register must be kept of all the men employed. 1 Bulletin de I'lnspcction du Travail et de I'HygieDe Industrielle, 1913, Nos. 5 and G, pages 421 to 424. 38 o ( DUE DATE 1 mu] L2 f99l 5FP 3 !Q 9^ ; ^ SEf'?^ 7| * mm 2 b 1994 ^^\ s j^ 9^' ;^ ^ 'i iU ^uu*» OCT 5 ^00* NOV 2 2 2004 Printed in USA tES it the -wing, COLUMBIA UNIVERSITY LIBRARIES 0023789298 I'-! ■''^;