Document k6d1EqbjQ6y429aeEed4NLN2O

FILE NAME: WR Grace (WRG) DATE: October 1934 DOC#: WRG014 DOCUMENT DESCRIPTION: 1934 Oct Letter regarding Division of Occupational Hygiene and Notes on November 27, 1934 visit to Almy Chemical Company. Letter marked Plaintiffs Exhibit P-5. Octooer 1L, 1324* 3Dra.wr3rr&sdaLi:A7 lEbayroCyh,alPiroens.1ldCaooutp,ay 35 Sorvcy Street Cubriere Baasasnasetts Eeaur jrzAlyt ' 7 ,&re est*oliahlA 1a tb i* daprtaaot aZUrlaloD ' o Cecuputicaul By^ime, en* o toa m a porpes#* o tJLcA s i l l . ba to ivo arlcm toa bal? to aplayara la tbo aootral o oo- n-- thy caaitlfla* causad 07 la4urioua suostsacu asad 1a lariaatry 3 a are aturtiA; o lu a very scu ll voy ana latead to aparata la u s occconic-l u, osxjier us is ccussisrteat sltb resarlad r u l arrice. 3a ara settla^ up & aa11. c a tu id l Isuor-tcry Car tae analyais o tas uottriis _ita .-.alca se eoae la coatoct 1a incastry sao "1 11 euploy cae ca lia t . Cur desist Dr. Horrey fl. ilast ls a ycao* o*a sao cooes to os Tito vrry olja recaaatecsticaa rca tbe Borrar Lep*rtueat o CucaiAtry una tba Borrara Scs;'al o Puulie Heultb. Sis actual ioaustrial xperleuca ota boaoT=rf beca linitcd to * ' 8 u s a r us ticaaical ussiat-At Cor tac Atloafcie Balala* Co p*rxy. " Bceauae it is jy Cira bells tbut tba vala o a laoor*tory su dolo* auca orb la rettly doauncea tArou*h flrst-iuioa * c > u iatuaco itb actual cocaltloos la lngastry, Z *sat to hav Dr. 21i-;3 scJce fon riclts to sauoucturiag planta la tbis otate. 3oulu yoa ba villla to lut aa scad Dr. u H o to yoor pl-at, to ucet sao* o your a-r> coa i e m t a sucb tina to tba proecoaca iaralvia* tac _ora._ tesis eaesieulo aa uo feais teU I ba p m i U o l a to i-e 1 d*y sr ~ ao apcAt la cxy vould, I a m r o , be nal! ^orto Mi %ii. : I^eaa proaisa rcu tbot Dr. L1a s ls oot tba sort too touid solee lilnsal ib uny -cay a cnlaaaca 1a tbc pluat. 3a la a Aial7 intc-Ili^aat yoan* uaa c a u sill ba v-itc ** -pprec-liTe os all I e aoy courteslea s ao to,o a . - ' 5ica unfred Sowiitd Elrtctor ` DIvI.Io a o Occuputiaiol E ^ i c u o and Deeomber 11 f IS34 and to the-Mnltlbostoa^oraD^^JTelDOle, on November 28, 1934 - - - By:' B. B. Slklns Official met: Mr. Egan (chief chemist) Mr. Ferguson (plant manager) Mr. Leach Mr. Edwards Mr. Ross Mr. Jensen Mr. Taggart `4 Br. Mr. Mr. Mr. Mr. Mr. MoMordle Bateaon Slagle Martin Maars Stowe (engineer) (superintendent, Hnltibeetos) > The more important eontaots are underlined. Note: Due to the nature of its business many of the processes of this company are unique. Items which it is bellowed may not be general practice are marked with an astertSlc_and should be treated as confidential until passed upon by an official of the company. . . The Dewey and Almy Chemical Company manufactures primarily latex cements and allied products, such as solvent rubber cements, rubberized fabrioa, and rubber bonded brake linings. It was because of their developments in this last field that they acquired the Wultibestos Company, which manufactures brake linings and clutch facings of all types. . -- Dewey and Almy Company Mr. 2gan showed me sbont the plant in Cambridge. Latex cements: - ' Rubber latex is obtained in aolutiona containing 35, 60 or 75 per cent solids. In tbs dilute solutions there is about three fourths of a per cent of ammonia, which keeps the solution at a pH of 11, axxd so prevents fermentation and spoilage. In the moat concentrated aolutiona the alkalinity la maintained by a mixture of caustic potash and a potassium cocoanut oil soap. Acsnonia lu preferable for most purposes because it evaporates off. Its concentration is ' so low that it is no problem except when the cement or compound la used in very large quantities. ' ' *7arloua materiale such as pigments end fillers are added to the latex solution in making the compound. One such material la a modifying soap mads from beeswax and ammonia under high pressure. Sulfur la added whenever it is desirable and possible to cure the rubber in the cement or other product. In the linings for tin cans sulfur can not be used but fortunately an uncured material is more satisfactory. For many purposes a latex cement Is inferior to an artificial rubber emulsion, made by masticating vigorously coagulated rubber and then dispersing it with protective colloids and other suitable chemicals. A cement of this type seemed much finar and more homogeneous then corresponding latex cements, and its cost as 3aid to be the same. 2 :-^etex aeaents are of Interest to us beoause they compete with solvent m ffi.'.aMMtit One of the chief uses of benzol la as a solvent for the latter, purposes non-toxic non-lAflanmabls latex 3amenta are better substitutes ^ o r toxic, inflammable benzol oementa than the slightly toxic but inflammable naptha cements* . . ~ Mr. Ferguson said that there had been a swing away from latex sealing campounda toward solvent compounds, but that he felt that its peak had passed and tha immediate future would sea an increased use of the latex produats. Solvent room: This company makes both benzol and naphtha a d v e n t cements end com pounds. the latter constitute about two thirds of the total, and It was said that probably next yeer three quarters of the solvent compounds would be made from naphtha. The so-called solvent room la the second floor of an isolated building. It is about 35* x 12* i 8 ' ( and contains two miXBra, for naphtha and benzol produota, respectively. Saoh mixer.holds about a hundred gallons. Exposure to: the solvent may occur chiefly in three places; the pump roam, the solvent room, end muddler room, in which the finished aement la loaded into drums for shipment. In the pump room there ia some leakage of vapor, or seamed to be, but the pumps are operated from outside, and the room is rarely entered. In filling the drums there la undoubtedly seme exposure, but the greatest hazard Is certainly In tha solvent room. The solvent ia ordinarily pumped through a meter into the mixer. The stirrers are heavy spiral shaped knives which twist and tear the small pieces of rubber which are introduced. Seme heat is evolved in this operation, so that the temperature of tha mixture is raised, the outside of the mixer being above body temperature when the process was observed. Tbs mixers are closed except far an opening in the top about 18w x 10" which is covered loosely except when materials are being added, when the batch is being in spected, and when it is being emptied. The addition of rubber (cut in small pieces) takes seme tima, as the several layers are torn apart by hand or they are fed into the machine. Sons other materials, such as wax, are usually added. In the operation observed inspections of the batch as it was being mixed were frequent. As the top of the mixer ia about five feet from the floor the tendency la for the workman to put his face close to the opening in locking in at the batch. After two to eight hours, depending chiefly on the kind of rubber used, the mixer is tipped on its aids and the batch of finished produst is dumped through an opening in the floor into the muddler. The dumping operation observed took four minutes, including the time required to rake out the residual compound. The opening in the mixer through which the substance is poured la about three faet from the floor, and the operator stands three to four faet away except when he is cleaning out tha residue. The extremely viscous and elastic ass was said to contain only thirty per cent of solids. Its vapor pressure would presumably be aopreolably more than 70 per cent of that of pure benzol, but the viscosity of the mixture should cut down its rate of evapora tion considerably. I 3 / A blower wee operating in the wall opposite the mixer, near the floor, and above it the window wee opened. The operator was between the window rnd the mixer, but a little to one aide most of the time. The efficiency of this system of ventilation seems somewhat Questionable. Teata on the air in this room (made by the insurance company) showed satisfactory conditions, however, it was said. The men working on this Job are given blood counts every three months and aa a rule ore transferred after aix to nine months. No real cases of benzol poisoning have been encountered. Alt dope: This impregnating materiel is a mixture of about five parts coal tar pitch and one part toluol. The components ore heated in mixing, and ventilating equipment has been ordered for the process. The fumes did not seem bed at the time a finished batch wne observed in the open mixer. Rubber bonded brake lining material: Certain brake linings, especially those for heavy work, are made Tram asbestos to which carbon black and other substances may be added, and rubber latax. The various materials are nixed in a paper beating machine, spread on a wire screen and the water sucked out, then pressed in a hydraulic preaa, cured end brought to the proper thickness with a sanding machine. The last operation is well ventilated, but the method of feeding the paper barter was said to be dusty and nesds improvement. Probably 3ome such method as was worked out at ,7alpole will be applied hers. None of these processes ware in operation. Artiflcal leather: A soft absorbent paper is passed through a latex solution containing sulfur, coloring matter, etc., and than over e series of heated rolls where the water and ammonia are given off and the rubber is cured. An exhaust system provides for the removal of the ammonia given off (estimated at three pounds, or about sixty cubic feet, per hour). , It is necessary to stop the machine for brief periods in order to attach new rolls of paper. If the stop 13 for too long the paper in contact with the hot rolls tends to disintegrate. 2ven ths short stops unavoidably made may cause variations in quality in the finished material. ' The rubberized sheet ia passed through a calender to bring it to the proper thickness. Two or more sheets are often cemented together, sometimes two or three rolls being combined on a machine similar to the impregnating mechine, but smeller. No provision for the removal of ammonia ia asds in thia case, but there was no appreciable odor of ammonia around the machine. If still thicker sheets are to be made, pieces about five feet sauers are cemented together by hand. In the operation observed a naphtha solvent cement was used. Other products: Soda lints, used in gas gases, is made in some quantity. chloride crystals ere also made, materials. - masks for absorbing phosgene, chlorine and Zinc chloride solutions and zinc ammonium f-omo dermatitis has been caused by these acid \ 4 Chloroform and toluene are used aa preaervotlYss. Carbon totra- eblorldo la also used for seas purposes. Apparently these are used in rel w atively small amounts. Another asall use of benzol la la claiming out drams* i The Mltibestoa Company Ur. MeMordle, ho designed a large par of the atHating equipment used at the plant, shoved me about There have been numerous oases of asbestosls developed here, and as a result the methods of manufacture have been greatly modified The cording proc ess has been drooped, the yarn being bought already 8pun, end a vet weave sub stituted for a dry weave process Sr Bateson said that more oases of asbestosls were developed In the weave room where the dust count was about seven and a half- . million particles per cubic foot, than In the carding room, where the dust count was touch higher The moat recent counts ran from half a million to two million, except at a carboloy saw, here it was 0.7 million, end at the paper beater during Its feeding (SI million) A new process has been developed for feeding the paper beater, the use of the carboloy saw is discouraged pending its removal, and the general ventilation has been greatly Improved since these counts were made Woven fabrics are used chiefly for brake linings, but for soma clutch facings sa well. Most of the latter and soma brake linings, especially for heavy . brakes, are moulded, or made originally cs an asbestos paper. For Impregnating materials asphalt, chlnawood oil, and bakellte resins are used Rubber bonded linings are not impregnated; the rubber bending Is dons in Cambridge, but all cutting, shaping and finishing is done in Walpole Veave room: The yarn consista of cotton and asbestos fibre wound around a small wire. The warp is dry as it loaves the spools but passes over a wet roll before going through the guide . so that the dust given off by the vigorous agitation of the dry warp in the weeving process is largely eliminated, since the yarn is wet at this stage. The spIndies of weaving yarn are soaked in water before usa The loon spools of dry yern ere shaken somewhat but undoubtedly by far the largest port of the potential dust is prevented frcm coming off. ' *0n acme of the loans c process of impregnating the yern as it is wovan is being tried. The roll wet with water la replaced with one wet with impregna ting solution, in moat cases asphalt in kerosene. This is supposed to give a more thorough impregnation and eliminates a process. It has the disadvantage of dirtying up the loom, however, and the fumes of the solution contaminate the air of the weave roan. A solution of resin was nlao being applied in this way; they have succeeded in eliminating toluol from th<? solvent for these mixtures. On one section of a loom a water emulsion of a raain imprgnant was being tried, it being both non-toxic and non-inflammable. The fumoa of kerosene near the looms usinr the asphaltic imprgnant were somewhat obnoxious. Impregnating room; The method still used for most of the woven nating the fabric efter it is woven. A long strip is tion, before and after which are placed drying ovens. seemed satisfactory. linings is thet of impreg run through a bath of solu Conditions In this room 6 Grinding roc: Here the elutah facings and brake linings are ground down to the proper sine, the required holes are drilled etc., and in this .roan the most strenuous efforts in ventilation here been made. The removal of risible dust seemed almost perfect in the case of all the grinding operations observed. The chief source of dust seemed to llo in the handling of piles of artloles in loading or unloading a machine. In some cases ventilation was even pro- Tided for these operations. One of the men operating an inside grinder (for the inside of clutch facings) wore a respirator, however. Clutch deportment: m the process of making moulded brake linings and especially olutch faolngs, asbestos is fad into a paper beating machine, where it la mlxsd with water, pigments, fillers and a little red lead, which helps the Imprgnant to harden. From here it Is pumped to the paper machine where a layer of the mixture is soread continuously on an endless belt, the water drained off, and ths re sulting sheet of asbestos paper is removed, pressed, end out up. Formerly the set of feeding asbestos Into this machine was very dusty. Row the bags of asbestos are emptied into a chute (in an enclosed room on ths second floor) and the water for the mixture is sprayed in simultaneously, wetting down the asbestos so that it la soaked with water when it enters the beater, and little, or no dust Is given off. The man handling the bags of asbestos wears a respirator, the operation taking but a few minutes. The room where this was done seemed surprisingly free from visible dust. This seumad to me a very satisfactory, common sense and sconcmloal solution of this particular problem. Twenty pounds of red lead are aprlnkled with a hand scoop into each batch mixed up In the paper beater. This is heavier than many lead compounds end none of It seemed to be dissipated in ths form of dust. I understood the workman to say that the maximum output of the machina was five botches a day. Clutch impregnating roam: Most of'the clutch facings are Impregnated with AR dope, a solution of a coal tar pitch in toluol, which is made in the Cambridge plant. A rack about 4*- x 5* x 6* is filled with clutch faolngs and then submerged in one of the tanks of dope, of which there ere three or four in a room about 28* x 12* x 8*. The solution is kept at 60 degrees 7. or higher, and the tanka ore covered except when the solution or solvent Is being added, when the rack of clutch facings la being introduced, and when the clutch faolngs have just been re moved and the excess solution is allowed to drain back into the tanks. There is no ventilation In this roan and the fumes ore said to be bed st tinea. The foreman said ho wouldn't enter the place on a damp dey, and that the men often got Jags from tho fumes. One of the men said he was often mode dizzy by the toluol vapor, and that he and hia colleague suffered con siderable discomfort generally. I 7 seemed to me that unless these men were exaggerating greatly the conditions should by all means be improved, a determination of the toluol, concentration in the air might be worth while. Two or three window blowers* to be operated when the tanks were open, might improve the situation suffi-- . ' olently for practical purposes. . - : . -... 3hlla the insurance company was said.to have Investigated these condltlons and to be satisfied, and while it le true that toluol is-not as In- sldlous a poison as benzol, or asbestos dust, and whlls there is same doubt about Its ever causing chronic poisoning, it Is still classified with benzol . in Bulletin 582 of the 7. S. Dept, of Labor. Certainly conditions suoh as apparently exist here should not be tolerated if they can be easily remedied. . alcoh. ol. Crums containing toluol were in some oases labelled as containing . ' - ;* v . -V ... - , . . . ' . General:. ' '' ' * lir. Jiciiordie said that sane dermatitis "was caused by the formaldehyde used with tar aoid in the manufacture of baksllte reelne. Respirators were worn on many odd jobs, -such as sweeping the floor, ' using the earboloy saw, etc. . t ./ In general the firm has been admirably thorough. Ingenious, and, I believe, effoetlve in the etepa taken to eliminate dusty conditions.