Document LpJ8N3jaXL2OYVmJQe0pMM265

FILE NAME: Oil Industry and American Petroleum Institute (API) DATE: 1961 July DOC#: API167 DOCUMENT DESCRIPTION: The Medical Bulletin Article - Industrial Hygiene Aspects of Mechanical Operations in a Petroleum Refinery Medical Bulletin J U L Y , 1% 1 K1TORS R. F. Schneider. M.D. N. J. Roberts. M.D. J. M. Daley. M.D. W. E. Wakclcy, Jr.. M.D. J. J- T hor pe , M.D. R. E. Lee, M.D. 'S. I*. Wanner, If.N. R. Mae D iarm iii. Med. Adm Constance Lima, Secretary STANDARD OIL COMPANY (NEW JERSEY) AND AFFILIATED COMPANIES V O L U M E 21 NUMBER 2 Conyr'ujht, IUGI, Standard Oi/ Compili)// fiVrir J r m ' i r J 30 P/n*, J\Vt York 'l. N, Y. Printed in U. S, A. Kxpnsmvs to rliemieals and physical agents hy workmen in the hiccliauical cralts cover essentially the entire realm nf industrial hygiene concent. Such problems range from the inhalation of and physical contact with vapors, (lasts and fumes to excessive heal, noise and radiation. Mechanical craftsmen ma y work ei ther in a centralized .shop or in the field. In general, the sever i t y of expos ure is g r e a te r with field work than with .similar work in the shop. Many limes field work must lie d one <in confined spaces w h e r e the provision of a d e qu a t e ventilation may he dillieiilt. Under these conditions, for example, a weldin' 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 eonstruelion have tended to increase the al r e ady imposing list of hazar ds. As an example, in the relatively new field of pel ro-ehcmicals m a n y solvents, catalysts and chemicals are used which were not previously encountered. Alloy metals and protective coalings are more and mure in use which may produce quite toxic dusts, fumes and gases under heated conditions or when uhrasi vo-hlast ed. The importance and scope of industrial hygiene ('valuation and engineering control of the environment in which the mechanical craftsman must work is f ur th e r evidenced by the fact that roughly 50',i of a refinery work force may be employed in the mechanical tr ades co mp ar ed to dli'v each for process and ot he r 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 me nt s of the envi r o n m e n ta l factors should be made by menus of industrial hygiene techniques to d et er mine the ex t en t of controls required. . C u CU " at W -CcJ -CC c = t: c: ^ * Ih -- ~ 7Z <t S c o r v; o -s eI s -r* y- ^^ 3i x - a. c ? n? > INDUSTRIAI HYGIENE ASPECTS OF MECHANICAL OPERATI ON IN A PETROLEUM REfINFRY Medical Research Division Esso Research and Engineering Company INDUSTRIAL HYGIENE COMMENTS ON MECHANICAL OPERATIONS This tabulation will not be complete for all refineries as some may have specialized mechanical work not covered here. Also in some locations certain mechanical jobs may not be done in the shops or departments shown in this listing. This is not important, however, since this listing is concerned with the job rather than where it mav be carried out. . Area BOILERMAKER SHOP Hazardous Items Noise Free Silica ' (see also welding) CARPENTER SHOP Paint Solvents Sanding Dust Noise Comments Many of the operations in this area produce noise intense enough to dam age hearing of attendant personnel. Cold riveting, chipping, and plate bending are exam ples of operations w hich might require reduction of noise level or personnel protection. During pipe bending the pouring of sand in and out, as w ell as the sand handling facilities, m ake the air dusty. If the sand used has a high free silica content, exposures to this dust m ust be m in i mized. If w eid in g is d on e in this shop, the p otential ex p o su res listed under welding should be included here. . Various solutions and solvents arc used for loosening and rem oving paint from o b je cts req u irin g carp en try. In m ost in sta n ces the solvents contain arom atic or chlorinated hydrocarbons and either general ventilation or local exhaust should be provided. Skin contact with solvents can produce derm atitis. Prompt rem oval of solvent contaminated clothing and the use of gloves and show ers reduce the hazard. Sanding operations duce considerable dust. O ften the work piece has been painte v.*iin m eta llic p igm ents, su ch as lead or m anganese, w h ich car. id the air w ith ex trem ely to x ic m aterials. Local exh au st sh ou ld be }-- >vided for this op eration . 5S 3M C E M J i & J a g L g SSa<BaEaa w W B ^ B g 3 S g g s < g C ^ ^ 258 x . '' Area ELECTRICAL SHOP FORGE and BLACK SMITH SHOPS H azardou s /rents Solvents, i.e. Benzene Carbon Tetrachloride Trichloroethylene Smoke F umes C yanides Radiant Heat N o ise Circular saw s, bandsaw s, planers, shapers, and the like, can be noisy, p articu larly w h en w o rk in g on hard woods. Efforts to isolate and enclose these ^operations should be considered. Many electrical shops use carhon tetrachloride or similar toxic solvents for cleaning electrical equipm ent. These m aterials may be sprayed or used as a dip. Carbon tetrach lorid e in particular is highly toxic. If required for cleaning electrical equipm ent, special arrangem ents hould be provided, such as ventilated hoods or booths, so ti. 11 e m p lo y e e s do not in h ale the vapors. In som e applications it is p ossib le to su b stitu te m eth yl chloroform (M AC .500 ppm; for carbon tetrach lorid e (M A C 25 ppm) therehy reducing the hazardous conditions. Most forges have only a canopy hood placed some distance above them. The draft caused by the heat of the forge and the stack effect of the hood is g en erally insufficient to satisfactorily control the smoke and fum es from forging. The hood should be m echanically exh au sted to assist the natural draft to provide a satisfactory c o n trol velocity over the entire free face area betw een the forge and the hood. It m ay be ex p ed itio u s to red u ce this free face area by partial enclosure. Case hardening som etim es em ploys cyanide salts. The entire operation where cyanide salts are involved should be under mechanical exhaust. This includes preparation of the salts, dipping and sprinkling of the salts over the heated w ork-piece, and w ork piece quenching. A t forges or furnaces, sh ield in g should be used to reduce the am ount of radiant h eat tran sm itted to the work place. T his is particularly true for openings of the furnaces through w hich the hot interior surfaces can be seen , su ch as the door, pyrom eter ports, and so forth. S everal op eration s in the area can p roduce high in ten sity noise, i.e.. drop ham m ers and furnace burners. Efforts to isolate and enclose these operations should be made. A r`?a INSTRUMENT SHOP H a zardou s Items M ercury Sol ven ts, i.e. Benzol C.-;rhun T*:rncklnri-!v Ti : r::**' t't : v :rnr C o n tin en ts M ercury is often sp illed w h en in stru m ents arc repaired and serviced. A ccum ulation of m ercury droplets on tables, floors, and other w orking a r c 's m ay ea sily resu lt in excessiv e am ounts of mcrcurv vnpnr m the atm osphere of the work area Careful tech - n:c,".:v< h-' avi! to avoid >ptll:-j*> of m crcurv. prop.--!'- INDUSTRIAL HYGIENE ASPECTS OF MECHANICAL OPERATION IN A PETROLEUM REFINERY <S^Sia3ta55<'. Er* * *'* .............*-* 14 '** t5*`' .. fl'ii s-.irr.,u .;> t lir ^ u ^ h wln..: . ti,i- hoi interior surfaces ran hr seen , such ns the door, pvrom eter n^rt* and so forth. * ' ` S everal operations in the area can produce high intensity noise, i.e., drop hamm ers and furnace burners. Efforts to isolate and enclose these operations should be made. Area INSTRUMENT SHOP Hazardous item s M ercury S olv en ts, i.e. Benzol Carbon Tetrachloride T r ic h lo ro e th y len e INSULATORS MACHINE SHOP M etallizing Degreasing A sbestos Cadm ium Lead N ick el Zinc N o ise Chrom ium F lu o r id e s Solvents C om m ents M ercury is often spilled w hen instrum ents are repaired and serviced. Accum ulation of m ercury droplets on tables, floors, and other w orking arers may easily result in excessive am ounts of m ercury vapor in the atm osphere of the w ork area. C areful tech niques should be follow ed to avoid spillage of m ercury: properly designed stands for tearing dow n and serv icin g m eters help toward this end. In addition, good housekeeping and im m ediate cleaning of spilled m ercury does much toward elim inating this hazard. (See attach ed d raw in g "S u g g ested F ea tu res for M ercury M eter R epair SU nd" M RD-N2-53). If solvents are required for cleaning instrum ents parts, exposure to their vap ors m ay occur. S o m e so lv e n ts, su ch as b en zol, or chlorinated solvents like carbon tetrachloride, are extrem ely hazardous. These solvents should be handled with care and used o n ly in w ell ven tilated areas. If rou tin e u se of these m aterials is required, special facilities should be installed for the handling and application. If the insulators reclaim old insulation by shredding, the shredding device or m achine should be provided with m echanical exh au st ventilation to prevent the dissem ination of asbestos into the breathing zone. The spraying of molten m etals and alloys on heterogeneous m etallic objects introduces fum es into the workroom atm osphere. Control of these fumes is n ecessary and is accom plished through local m echanical exhaust ventilation. F um es of lead, lead alloys, cadmium and beryllium arc extrem ely toxic and com plete respir atory protection must be provided for the operator and other w orkers in the fume area. O ccasionally solvents are required for cleaning w ork-pieces. T hese solven ts should be han d led carefu lly and used only in well ventilated areas. If routine use of these m aterials is required, special facilities should be installed for their handling and applica- : <v, .i' ? ~ y P71'- .y*?v mu n-- r Twnt^www Area Babbitting Tool Grinding MASONS Hazardous item s Lead C adm ium Arsenic Cobalt B e r v iliu m Free Silica Radiant Heat C om m ents tion. M any satiMarif * com m ercial units are available for this purpose. Sk in cor.i'.ti-' oust be a void ed . S u ch so lv e n ts as b en zen e and carbon tetrachim :-..e h ave a h igh order of to x icity and special caution is required. B ab b itt m etai is lne! nam e orig in a lly g iv en to allo y s of tin. lead, and antim ony. Newer m aterials m ay also contain cadmium and arsenic. Health hazards due to m elting of babbitts depend upon se v era l factors such as: pot size, tem p eratu re of m elt, d rossin g procedure and disposal m ethods, frequency of m elt disturbance by ladling and level of housekeeping. Good industrial practice requires therm ostatic control of tem perature, careful drossing and disposal of dross in a separate covered receptacle. The need for m echanical exh au st depends prim arily on the frequency of the operation and quantities handled. E xh au st ven tilation is recom m en d ed for large pots u sed for m elting metal on a production basis. G rinders for sharpening tun gsten-carb id e tools should have local m echanical exhaust ventilation to prevent the inhalation of cobalt by the men. This cobalt dust com es from the cem ent used to bond the cutting tip to the sh ank. The w heels for grinding and sharpening non-sparking tools should have mechanical exhaust because these tools are m ade of a beryllium alloy. Som etim es such grinding and sharpening equipm ent is placed inside the tool crib and all operations arc restricted to this area. H igh silica content fire-b rick s m ay be cu t or ground to so ecia l shapes and sizes. The brick m asons should have a cut-off saw containing an integral exhaust system to keep the dust aw ay from their breathing zone. Furnaces lined with fire-brick m ust have the lining removed p eriod ically. This operation su b jects tho w ork ers to high co n cen tra tio n s of dust. A s the w ork is u su a lly in term itten t, approved A rea Hazardous Item s Com ments a i r - l i n c r e s p i r a t o r s s h o u l d h e w o r n w h i l e t h e w o r k is in p r o g r e s s . I,, the event air-line respirators are im praciicaole. the liter-typo respirator approved for protection against pneum oconiosis-pro d u c i n g d u s t s '.rill p r o v i d e a d e c p i n t e p r o t e c t i o n u. .^ >2.. !' : .;i.. (".V.W in <'-hr!rK." ni.yv I.- cu t or cruum i to sh.iji.'s and size:;. The hrick m asons should h ave a cu t-off saw containing an integral exhaust system to keep the dust aw av from tn n r breathing zone. ' Furnaces lined with fire-brick must have the lining removed p eriod ically. T in s operation su b jects the w o rk ers to high con centrations of dust. As the work is u su ally interm ittent, approved H a z a r d o u s Itevis Pigm ents S o lv en ts Thinners Paint Rem overs C om m ents a ir-lin e respirators should he worn w h ile the w ork is in progress. In the event a ir-lin e respirators are im practicable, the filter-type respirator approved for protection again st p n eu m ocon iosis-p ro ducing dusts w ill provide adequate protection. W ork w ithin furnaces som etim es exp oses the m asons to high h eat loads. S in ce m ost of this heat is from radiation, it cannot be easily controlled. Reflective, air cooled cloth in g m ay help in w ith sta n d in g the high tem p eratu re. O ften, the b est th a t can be done is to lim it the length of work tim e so as to control the duration of exposure. P ain t is applied by either brush or sp ray gu n . The hazards of the work com e from toxic pigm ents, solvents, thinners, and re m overs. P igm ents m ay contain lead or other m aterials having toxic properties. Arom atic m aterials, such as benzol, toluene, and chlor inated m aterials, such as carbon tetrachloride and trichloroethylene m ay be em ployed as solvents or thinners. Both benzol and carbon tetrachloride are popular m aterials for paint rem overs. Inhalation of these m aterials may take place around painting operations. Good paint rem overs are also strong skin irritants. Paint shops shouicl have w ell ven tilated d ryin g areas so that the solvent vapors being em itted during the drying process do not contam inate the general work area. An ex h a u st hood with a turn table m o u n ted in front of it can p rovid e a m ea n s o f control w hen spray-painting sm all objects. For isolated spray painting, personal protective equipm ent should he used and any group of painters should he placed under m edical supervision. T he health hazard of sandblasting is the inhalauon ol free silica dust possibly leading to silicosis after prolonged exposure. Both the san d h laster and his h elp er arc e x p o se d to t : type ot dust while blasting. There are generally two types of sandblasting. both ot thesp require protection for the w o rk er. T h e first is sar ininsting in on e cen tral location to w hich the parts are b rou gh t to be .leaned. INDUSTRIAL HYGIENE ASPECTS OT M K H A N I C A l OPTRATION IN A PETROIEUM REFINERY Area TIN SHOP Hazardous Items Lead F lu o rid es C ad m iu m Zinc C h lo rid es Comments Com m only this work is done in a room or cabinet. The other type of sandblasting is done in field locations since the w ork is too large to m ove. In this type, the operator m oves over the entire structure. The m ethods of controlling exp osu re to dust in these tw o situ ation s are different. W here sandblasting is done in a room or cabinet, it is usual to supply these structures w ith exh au st ventilation. W here the operator stsfbds on the outside of a cabinet or booth, the ventilation m ay be designed as to preclude the wearing of a san d blasting Helmet. H ow ever, w here the operator stands inside o f the cabinet he m ust w ear an approved blasting helm et. W here san d blasting is done in the open or on process equipm ent, structures, and the like, about the only m ethod of protecting the individual is for the operator to use an approved sandblasting helm et. D u st type respirators m ay be adequate for the helper. The actu al e x p o su r e to silica d u st can be ev a lu a ted o n ly b y dust counts. N ear the nozzle w here the blaster h im self stands, it is obvious that the exposure would be extrem ely high. Therefore, the counting of dust in such a situation is useless as it is not n eed ed to reveal a health hazard. On the other hand, w h ere it is ob served that other w o rk ers are being ex p o sed to silica d u st, it m a y be desirable to determ in e the level of exposure. This should be d on e by an individual trained in the industrial hygiene techniques of collecting and counting dust sam ples. Exposed personnel should be placed under close m edical supervision. (1) T in-L ead. The heating of tin-lead solder to the flow point so that it w ill bond w ith other m etallic surfaces w hen cooled is usually performed with a hand soldering-copper or tinning pot. The tem perature of the m elt is u su ally not high enough to produce in ju riou s con cen tration s of lead fu m es. H o w ever, d u rin g the "s h a k e off" of sold ered parts, fin e ly d ivid ed particles of lead m a y be dispersed to the general room atm osphere. Control of the ''shake off* exp osu re w h e r e large parts are in v o lv ed , is through m ech a n ica l exhaust ventilation. Area Hazardous Item* K-omments F luxes and various cleaning solutions contain chlorides or free hydrogen chloride. A hood with m echanical exhaust should be provided in any acid-cleaning area. (2) S ilver Solder. The process of silver soldering, som etim es known as hard soldering, involves the use of an oxyacetylen e or c ity -g a s torch to m elt the silv er so ld er in the p resen ce of :i Mux. W hen borax nr huracic acid is us**H nn lu-aldi h i?.*rd Lead Fluorides C ad m iu m Zinc C h lo rid es p i . -i j n d t T - : i m"i K `; > j ; i v i M ' i n . (1) Tin-Lean. The heating of tin-lead solder to the flow point so that it w ill bond w ith oth er m eta llic su rfaces w h e n c o o le d is usually perform ed w ith a hand soldering-copper or tinning pot. The tem perature of the m elt is usually not high enough to produce in ju riou s co n cen tra tio n s o f lead fum es. H o w ev er, d u rin g th e `'sh a k e off*' of sold ered parts, fin e ly d ivid ed p articles o f lead m a y be dispersed to the general room atm osphere. Control of the "sh ak e off** ex p o su re w h e r e large p arts are in v o lv ed , is through m ech a n ica l exhaust ventilation. m INDUSTRIAL HYGIENE ASPEC1S OF MECHANICAL OPERATION IN A PETROLEUM REFINtRY Hazardous Items F lu x e s Fluorides Chlorides M etals C ad m iu m Chromium Lend M anganese Zinc N ick el Other Oxides of nitrogen Ozone Radiation Infra-red U ltra-violet X and Gamma Comments j F luxes and various cleaning solutions contain chlorides or free I hydrogen chloride. A hood w ith m echanical exhaust shpuld be | provided in any acid -clean in g area. j f 2> S i l v e r S o ld er. T h e p ro cess of silv e r so ld erin g , s o m e tim e s ' known as hard soldering, in volves the use of an oxyacetylen e or city -g a s torch to m elt the silv er solder in the presence of a flux. W hen borax or boracic acid is used, no health hazard is presented i by the flux. H ow ever, som e types of work call for the use of a flux I containing fluorides. T h ese fluorides are hazardous if b reath ed in < appreciable quantity. W orkers also should be cautioned not to get , fluoride flux on the hands. . j Som e silver solders contain appreciable quantities of cadm ium w hich can be vaporized into the worker's breathing zone. C ontrol. ' w hen required, is through m echanical exhaust ventilation. If w eld in g operations are conducted in this shop p otential exp osu res sim ilar to the list under welding should be con sid ered . There are two classes of w elding--gas and electric. The gas types are oxyacetylene. oxvhydrogen. and atom ic hydrogen. E lec tric types are m etallic arc. carbon arc and resistance. The n ew er , m ethods such as gas-shielded arc. subm erged arc. and m agnetic are. and m agnetic flux, are electric also. T he hazards in cid en t to the operation are varied in their nature and severity. . The requirem ents for health protection and ven tilation in . w elding and cutting have been established by the A m erican W elding Society on the basis of the three follow ing factors w hich govern the am ount of contam ination to which w eld ers m ay be exposed: 1. D im en sion s of sp a ce in w h ic h w eld in g is done. 2. N u m ber of w eld ers. ' 3. Possible evolu tion of hazardous fum es and gases accord in g to the m etals involved. . *4 ^ t* i it i ti l o Area i u " i Ji i i i c'i.at-* .'^J J "-T Hazardous Items ; Com m ents As a guide on ly, 2000 CFM w eld er should be su p p lied as gen era l ventilation when w elding or cutting mild steel in spaces of less than 10.(\] i cu . ft. w eld er or in a room h aving a ceilin g h eigh t of less than 1' N atural ven tila tio n m ay be sufficient w h en these con fined s; ic*? ; sta tio n s do not e x ist. F um es from b erylliu m , cad m ium , lead, chrorr. or m ercu ry are extrem ely toxic and local ex h a u st and or supp. 'r'i air respirators are gen era lly required. W here local e x h a u st is used, a freely m ovable hood, intended to be placed b y the w e ld e r as near as practical to .the w ork, sh ou ld provide sufficient air flow to m aintain 100 lin ear*ft. m in. in the direction of the hood at its rem otest distance from the point of welding. Eye protection m ust be provided; the density of color of the protective glass being dependent upon the intensity of the radiation. Flash shields should com pletely enclose the inert gas w elding area to protect the e y e s of w ork ers other than w elders. The bottom of the sh ield s sh ou ld be a short distance above the floor (o h elp create natural convection currents. The new er welding processes produce around ten tim es the am ount of ultraviolet radiation as does ordinary arc w elding. P rotection of onlookers in these cases is exceedin gly im portant. X -ray m achines and gamma ray sources are used to test w elds. Film badges and direct reading pocket dosim eters shouid be worn during radiographic work. Short exposure times and the greatest possible distance from the radiation source are the m ost effective means of reducing exposures. TV* ,n'