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e. . ii The Medical Bulletin JULY. 1%1 EDITORS R. F. Schneider. M.D. J. J. Thorpe. M.D. N. J. Roberts. M.D. R.E.U-e.M.D. _ J. M. Daley. M.D. S. 1\ WjKer.n.*S. W. S. Wakciey, Jr. M.D. H. Mac Dianmul. Med. A<lm Consumer Lima. Secretarv STANDARD OIL COMPANY tNEW JERSEY) AND AFFILIATED COMPANIES - VOLUME 21 NUMBER 2 Cvpuritjhi. 13Q2, Standard Oil Com jMtti t/ (nVir Jersrul 2l) RirJcj/#Her Ptaso. N*tn York 2U. N. Y. Printed in U. S A. %t TS W % v - -rt V- idr* */r*- Ti ii f? INDUSTRIAL HYGIENE ASPECTS OF MECHANICAL OPERATIONS IN A PETROLEUM REFINERY W. H. MEYER and F. W. CHURCH Ks*** Hrseareh and Eneinocriiic Gmijumy Exposures to chemicals and physical agents by workmen in the mm-hamcal crafts cover essentially the entire realm of industrial hygiene concern. Such problems range from the inhalation of and physical contact with vapors, dusts and fumes to excessive heat, noise and radiation. Mechanical craftsmen may work either in a centralized shop or in the field. In general, the severity of exposure is greater with field work than with similar work in the shop. Many times field work must be done in confined spaces where tlac provision of adequate ventilation may be difficult. Under these conditions, for example, a welder may have higher exposures than normally occur in shop welding. In many industries, as in petroleum, automation and mechanization have reduced the exposures to process operators. Proportionate reduc tions have not always been made in the mechanical crafts. In addition, new processes "and materials of t uusti"action have tended to increase the already imposing list of hazards. As an example, in the relatively new field of petro-chemicals many solvents, catalysts and chemicals are used which were not previously encountered. Alloy metals and protective coatings are more and more in use which may produce quite toxic dusts, fumes and gases under healed conditions or when abrasive-blasted. The importance and scope of industrial hygiene evaluation and engineering control of the environment in which the mechanical craftsman must work is further evidenced by the fact that roughly 50'T of a refinery work force mav be employed in the mechanical trades compared to 25 r/> each for process and other employees. In the attached listing are summarized some of the more important mechanical operations, the potential hazards and suggestions for con trol methods. While basically prepared for shop operations, the general principles can be translated to other conditions. Actual assess ments of the environmental factors should be made by means of industrial hygiene techniques to determine the extent of controls required. [ [ | ^ j 1 {. f- io/i -- eaz "T--\ %? C l/. v. y oc `f o i o 3' r, H.'"E a r. < = IL" c c r 5 r. a. -r ^ # 3 j. o -- c o' ^ ~ < 3 <* ?r a -* _ o. ^c ~ - c: a. r~ iv u ttn o N i v U J N H is w n jio a n w h i n o i i t s 3 * 0 iy d iw v iid iw r or a- Medical Research Division Esso Research and Engineering Company INDUSTRIAL HYGIENE COMMENTS ON MECHANICAL OPERATIONS This labulalion h ill not be complete /or all refineries as some may have specialized mechanicalw...o...r.n.....n. .o. i covered here. Also in some locations certain mechanical jobs may noi be done in the shops or departments shown in this lifting. This is not important, however, since this listing is concerned wit [i the job rather than where it may be carried out. Aren f/<nnrdm iienn Comments I t i BOILENMAKEH SltOP Noise Free Silica tree also welding) ^ Many of the operations in lids area procure noise intense enough to damage hearing ot attendant personnel. Cold riveting, chipping, and plate bending are examples of operations which might require reduction of noise level or personnel protection. i I During pipe bending the pouring of sand in and out, ns well ns the simtl handling facilities make' the idr dusty. If the sand used has a high free silica content, exposures to this dust must be mini' miied. ,I I t It wadding is dnr in this shop, the potential exposures listed i under ueMiiiy should lie included here. . CAIU'ENTEn StIOP Paini Snhcnls Various solutions and solvents arc used for loosening and Sanding Dust removing paint from objects requirin'.,' carpentry. In most instances i Noise the solvents contain aromatic or chlorinated hydrocarbons and citlu'i general ventilation <' local exhaust should he provided. Skin contact with solvents can produce dermatitis. Prompt removal of i solvent contaminated clothing and the use of gloves and showcis reduce the hazard. Saluting operations duw considerable dust. Often the work piece has been pointv will* metallic pigments, such ns lead or maneanrsc. which can ad the air with extremely toxic materials. Local exhaust should be |"i\'lded for this operation. KtsoncamJKriCB ^nrif?r^xr*aftH-asw**KarnTxz^^nci*4rgrprin*-ajn!Ti/rrLZT'.:iyr jyggwgwgn^r'.^y.a^ajtwoirtw'mr^r^rrwr gsz Arta ELECTIUCAL SHOP FORGE and RLACK- SMITH SHOPS r*T i(n:nrclnus firm* Solvents. i c. IlciUPMC Carbon Tetrachloride Trichloroethylene Smoke Fumes Cyanides Radianl ileal Noise Comments Circular saws, bandsaws, planers, shapers, and (he like, can he noisy, particularly when working on hard woods. Efforts lo isolate and enclose these ^operations should tic considered. Many electrical simps use carbon tctrnchloride or similar toxic solvents lor cleaning electrical equipment. These materials may lie snrayed or used as a dip. Carbon tetrachloride in particular is highly toxic. H required (or cleaning electrical equipment, special arrangements should he provided, such ns ventilated hoods or booths so ti ll employees do not inhale (lie vapors. In som-r applications it is possible io substitute ntelhyi chloroform (MAC 5fMJ ppm) (or carbon tetrachloride (MAC 25 ppm) (hereby reducing (he liataidous Conditions. , Most forges have only a canopy hood placed some distance above (hem. Tbe (halt caused by (be heat of the forge and the stack effect o^| the hood Is generally insufficient to satisfactorily control the s'nokc nod fumes from forging. The hood should be mechanically exhausted to assist the natural draft lo provide a satisfactory con trol velocity over the entire free (occ area between the forge and the hood. U may be expeditious to reduce this free face area hy partial enclosure. Case hardening sometimes employs cyanide salts. The entire operation where cyanide sails are Involved should he under mechanical exhaust. This includes preparation of (lie salts, dipping and sprinkling of the salts over the heated work-piece, and work piece quenching. At (urges or furnaces, shielding should he used lo reduce the amount of radiant heal transmitted lo the work place, lids is niirticuiuriy (rue for openings of (he furnaces through which the hot interior surfaces can he seen, 6uch as the door, pyrometer ports, and so forth. Several operations In the area can produce high hilcnsitv noise. I.e., drop hammers and furnace burners. Efforts to Isolate and enclose these operations should he made. 'ptT /Irvo INSTRUMENT SHOP IfniiulniM (li'iiii Mercury Huh cuts, i c Denial Cuihuh Tetrachloride 1 n hlm eth-dnu- Comments Mercurv is often spilled when instt tnncnla arc repaired and serviced Accumulation of mercury droplets on tables, (lours, and other working arc s may easily result in excessive amounts ol mrrrury vapor m the atmosphere of the work area Careful levhmtjuw Should h.* inlio.wd lo avid spill;.-.:** of imicuiv. pcnpv.lv Jwvrrnl operations m the urea cn,., produce high inlenrit I c . crop hammers and furnace burners. EHorts to isot. ehclose these operations should he made. StUll r. Area j INSTRUMENT SHOP INSUl.ATOnS MACJIINESIIOP Metallizing DcyrcaMnB lltizordoiu item* Mercury Solvents. I.c. llcnzol Carbon Tclrorhloride Trichloroethylene Asbestos Cadmium I .end Nickel ?.tnc Noise Chromium Fluoiides Solxents Commoiii Mercury is oMcn spilled when instruments Are repaired and serviced. Accumulation of mercury droplets on tables, floors, and olbcr working nrers may easily result in excessive amounts of mercury vnpnr in the atmosphere of the work area. Careful tech- nitpics should he followed to avoid spillage of mercury: properly designed stands for tearing down and servicing meters help toward this end. In addition, good housekeeping and immediate cleaning of spilled mercury docs much toward eliminating this hazard. (Sec attached drawing "Suggested Features for Mercury `Meter Repair Stand** MIID-N2-53). *J If solvents are requited for cleaning instruments parts, exposure to their vapors may occur. Some solvents, such bs benzol. or fhlorjualcd solvents like carbon tetrachloride, aj'e extremely hazardous. These solvents should he handled with care and used rnly hi well ventilated areas. If routine use of these materials is required, special facilities should he installed for .the handling ^nnd application. I If the insulators reclaim old Insulation bv shreddins. the shredding device or machine should he provided with mechanical exhaust ventilation to prevent the dissemination of asbestos into the breathing zone. Tim spraying of molten metals nnd alloys on heterogeneous -metallic objects Introduces fumes into the workroom atmosphere. Control of these fumes is necessary and is accomplished through local nu'chanioal exhaust ventilation. Fumes of lead, lead alloys, cadmium and beryllium arc extremely toxic and complete respir atory protection must he provided for the operator and other workers in the fume area. Occasionally solvents ore required lor cleaning work-piece*. These solvents should he handled carefully and used only in well ventilated areas. If routine use of these materials is required, special facilities should be Installed for their handling and applica- Zo c A X 1O in io It l I nX> iz I -- om to o2 Z X O c J to on THE MEDICAL BULLETIN Area Babbitting Tool Grinding MASONS ((aggrdoas Items i Lend Cadmium Arsenic Cobalt Beryllium Free Silica Kadinnt Heat Comments tVn. Many sntb'n.'h - commercial units nrc available lo< this purpose. Shin coitl n must be. avoided. Suclt solvents ns hcnccnc atid carbon telnuhlx. -ic linvc a high order ol toxicity and special out ion is required. Babbitt metal is Inc name originally given to alloys of tin. lead, and antimony. Newer materials may also contain cadmium and arsenic. Health hnrnrds due to melting of babbitts depend upon several (actors such as: pot site, temperature of melt, droning procedure and disposal methods, frequency of melt disturbance by lodling and level of housekeeping. Good industrial practice requires thermostatic control of temperature, careful drossing and disposal of dross in a separate covered receptacle. The need for mechanical exhaust denends primarily on the frequency of the operation nnd quantities iiandled. Fxhansl ventilation is recommended for large pots used for melting metal on a production basis. H Grinders (or sharpening tungsten-carbide tools should have local mechanical exhaust ventilation to prevent the inhalation ol cobalt by the men. This cobalt dust comes from the cement used to bond the cutting tip lo the shank. The wheels for grinding and sharpening non-sparking tools should have mechanical exhaust because these tools are made of a beryllium alloy. Sometimes such grinding and sharpening equipment Is placed inside the tool crib and all operations arc restricted lo Ibis arcu. . High silica content fire-bricks may be cut or ground to snocial shapes and sires. The hrick masons should have a cut-off saw containing nn integral exhaust system lo keep the dust away from their breathing tone. Furnaces lined with fire-brick must have the lining removed periodically. This operation subjects the workers to high con centrations of dust. As the work is usually Intermittent, approved Area Jfotordom (Icon Corn meats airline respirators should be woin while the work is in progress. In tlw event air line respirators are impracticable, the liltcr-type respirator approved (or protection against pncumuconusfs-?>rod'.icmg dusts will provide adequate protection \V,uh dm. Mr: uv. vim-tilsii-n ..... .. tho tU.Kon* ! hil*h I "*w Arrn PAINT SHOP i SANDBLASTING KJ Hw-ii hrcathini* mnc IP MU* MMmi IO kcc'ji llic <ln\l r IMM ..r.i ,,r,i,|iP* lir1 "',1' l)'P,,r'c,< *< lnvc the lM.il,i; iclIMM.-d IMf M.lMally n,ls opc.Hon subjects the worker* lo hii;h' con centrations of dust, As the wok is usually intermittent. ap,noted i I //mnrdoiM ilcnif Pigments Solvents Thinncis ` Point Removers ' H Free Silica Nohr CoMiinrnlj nil - line respirators should he worn while the work is In progress. In the event air-line respirators ore impracticable. tiic filter-type respirator approved for protection against pneumoconiosis-producing dusts will provide adequate protection. Work within furnaces sometimes exposes! the masons lo high heat loads. Since most of this heat is front radiation, it cannot he easily controlled. Deflective, air cooled clothing may help in with- standing the high temperature. Often, the lies* that can be don* is to limit the length ol work lime so ns to bonlrol the duration of exposure. j' Paint Is applied by either brush or spray gun. The hai.nrds of the work conic from toxic pigments, solvents, thinners. an<i removers. Pigments may contain lead or other materials having toxic properties. Aromatic materials. such as benzol, toluene, and cldorinated materials, such as enrhon tetrachloride and trichloroethylene may be employed ns solvents or thinners. Roth benroi and caihmi tetrachloride arc popular materials for paint removers. Inhalation of these materials may take place around painting operations. Good paint removers arc also strong skin irritants. Paint shops should ha\* well ventilated drying areas so that the solvent vapors bring emitted during the drying nrocess do tint i-Miitaminalc the general work area. An exhaust hood with a turntable mounted in front of it ran provide a means of control lieti spray-painting small objects. For isolated spray painting. personal protective equipment should he used and any group of painters should he placed under medical supervision. The health linznid of sandblasting Is the inhalation ut free silica dust possibly lending to silicosis after prolonged vximsui e. Moth the sandblaster and Ids helper are exposed to (' ; ivpc of (Ills'! while blasting. . There arc generally two types of sandblasting. belli of these require protection for the worker. The first is sar Jid.vtliug in one central location lo which the parts are brought to be leaned. I< * J> |J I I1 |' j' ' - ( " i. ' ,; Jj |' ( > j c ^ \ , : j - /AW* .^0 F^j I e?s /Wca TIN SHOP y4' Area 4 lia:ofdoiu Hems Lead Fluorides C^ilniiuirt Zinc Chlorides Commonly (hi* work is done in a room or cabinet. The other type of sandblasting Is done in field locations since the work is loo large lo move. In tills type, the operator moves over the entire structure. The methods o( controlling exposure lo dust In these two situations arc different. Where sandblasting is done in a room or cabinet, il is usual lo supply these structures with exhaust ventilation. Where the operator shlhris on the outside ol a cabinet or booth: the ventilation may be designed as (o preclude the wearing of a sand blasting helmet. However, where (lie operator stands inside of the cabinet he must wear an approved blasting helmet. Where sand blasting is done In the open or on process equipment, structures, and the like, about (he only method of protecting the individual is for the operator to use un approved sandblasting helmet. Dust type respirators may he adequate lor the helper. The actual exposure to silica dust can be evaluated only by dust counts. Near the nniele where the blaster himself stands, it Is obvious that the exposure would he extremely high. Therefore, lire counting of dust fn such^a situation Is useless as il is not needed to reveal a health hninrd. On the other hand, where it is observed that other workers are being exposed to silica dust, il may he desirable to determine the level of exposure. This should be done by an individual (rained in the industrial hygiene techniques of, ` collecting and counting dust samples. Exposed personnel should be placed under close medical supervision. : {II Tin-Lead. The healing of tin-trad solder to the flow point so that il will bond with other metallic surfaces when cooled is usually performed with a hand soldcring-coppcr or tinning pot. Tiic temperature of the melt is usually not high enough lo produce injurious concentrations of lead fumes. However, during the ``shake off* of soldered parts, finely divided particles of leod may he dispersed to the general room atmosphere Control of the ''shake off exposure where large parts arc involved. Is through mechanical exhaust ventilation. t o n k tm C a z "** Hazardous Items Comments Fluxes and various cleaning solutions contain chlorides or free hydrogen chloride. A hood with mechanical exhaust should he provided in any acid-cleaning area. (2) Silver 5oMer The process of sihei soldering, smnerancs known ns hard soldering. Involves the Use ol nn oxyacrlylrnc or city-gas torch to melt the silver solder its the presence of :i ll'.is When borax or horaeie acid is-used n* lo-uhli hi.rd i* pi-vern I i** *< Area WFLDING and CUTTING riuomios Cadmium Zinc Chlorides /** so that it will bond with oilier metallic su'biccs w * 0 is * * usually performed with * soMering-copper at mini; pot 1 The temperature ol the melt is MMiilly not hit'll enough to produce' . ' i Iniurinus ronccnli ations of lead lumes. However, during the "Shake * . off nl sold'*io(| parts, lincly divided particles ot lead may he . dispersed to the general room atmosphere Control ol lire "shake | off exposure where large parks are involved, is through mechanical' . , I exhaust ventilation. I Hazardous Items fluxes fluorides Chlorides Metal* Cadmium Chi nniium l.cul Manganese Zinc Nickel Other Oxides l nitrogen Ozone Rdi(ion infra-red Ultra-violet X .nut Gamma Commentt Fluxes and various cleaning solutions contain chlorides or free hydrogen chloride. A hood with mechanical (exhaust shpuld lie provided in any acid-cleaning area. \ (21 Slli'er Solder. The process ol silver soldering, sometimes known as hard soldering, involves the use of pn nxyacetylcnc or rily-gas torch to melt the silver solder In the [presence of a flux. When borax or hnrnclc acid is used, no health hazard is presented by the flux. However, some tvpes of work call for the use of a flux containing fluorides. These fluorides arc hazardous if breathed in appreciable quantity. Workers also should be cautioned not to gel fluoride flux on the hands. , Some silver solders contain appreciable quantities of cadmium which can be vaporized into the worker's breathing zone. Control, when required, is through mechanical exhaust ventilation. If welding operations are conducted In this shop pntruti.il exposures similar to the list under U'eldini; shpuld he considered. There arc two classes of welding*-gas and electric. The gas types nrc nxvacctytcnv. oxyhydvngcn, and atomic hydrogen. Elec tric types are metallic arc. carbon nrc and resistance. The newer methods such as gas-shielded arc. submerged arc. and magnetic arc. and magnetic (lux. nrc electric also. The hazards incident to the operation arc varied in their nature and severity. The requirements lor health protection and ventilation in urhliug and culling have been established by the American Welding Society on the basis of the three following factors which govern the amount of contamination to which welders may he exposed: '* 1. Dimensions of space in which welding is done. 2. Number of welders. ` H. Possible evolution of hazardous fumes and gasrs according to the ntckiii involved. i; l i; t; li . \ < < 1 2 > I jizjN m ? wnnosM J 4 red t l/n:nrilou* (trmi Comments As a guide only, 2'100 CFM welder should lie supplied as general ventilation when welding or culling mild steel in spaces ol less than lO.I'w cu. (I. welder or In a room having a culling height of less than I*' Natural ventilation may he sufficient when these confined sj tre I iltnliwis do Jtol exist. Fumes from Iwryllium, enthuhim, lead, eh ion. or mercury are extremely toxic and local exhaust and or supp. *r`i air respirators are generally required. Where local exhaust is used, a freely movable hood, intended to he placed hy the welder as near ns practical to .the work, should provide sufficient air flow to maintain 100 linear *ft. min. in the direction of the hood at its remotest distance from the point of welding. Eye protection must he provided; the density of color of the protective glass being dependent upon the intensity of the radiation. flash shields should completely enclose the inert gas welding area to protect the eyes ol workers other than welders. The bottom of the shields should hr a short distance above the floor to help create natural convection currents. The newer welding processes produce around ten times the amount of ultraviolet radiation ns docs ordinary arc welding. Protection of onlookers In these cases is exceedingly important. 'V X-ray machines and gamma ray sources arc used to lest welds. Film badges and direct reading pocket dosimeters should he worn during radiographic work. Short exposure limes and (he greatest possible distance from the radiation source arc the most effective means of reducing exposures. I i* .o ! o X C. vcuvmc m rs VQUIK U t il Ij fcr~ -iU 410 tn-o n XH o m SUCCES7B FEATURES_FOR HgRClgT METE.fi REPAIR STAHO 01Vf*S10*S Att OXIT SVCSISTIOKS 1X0 1X IOT CXI nut \ cn if coxttsifiw xAOf nos sxtrT siru a !; ixox.xobxiss.iuo ox corn usio. TXOUCX SlOXfSTO 0*11* 1*0 ISftUfO YITK Wt(l. U0UVT1XS *OSTS ixt SlICX SUE 1X0 KtlCXX 10 MICE mu* COXVlXUttlT >0X XfUltKll VOXXIIC UttU TXOWCX 10 It ViSXfO 00! Vl!x YAXSOl OCCISiOXlllT 10 XEHOVE ICOMUUHO CXUSE U'O OIL. in cxiexs iso cifyjcrs to u cicsio it suoixc o mm. hi msuoxtu somefs ' TO If ?T TO 1 Kiliwox,