Document 4GmJpVXX7eL6kXJqXZQZYe1j

FILE NAME: National Safety Council (NSC) DATE: 1939 May DOC#: NSC219 DOCUMENT DESCRIPTION: NSC - National Safety News - Settling the Dust Problem By J O H N M. ROC HE Snfetu Kngineer,Industrial Division, S'nlw m l Safely Council T HE inclusion of occupational disease claims in the compen sation laws of several states, a few years ago, caused an almost hys terical response from plant operators and their insurance carriers. Because of the threat of retroactive compen sation payments for past cases, vi sions of ruin seemed all too real. Hap pily, the fears proved groundless, for in every case the laws weie modified so that the burden was equitably dis tributed between the employer, the cartier and the state, with just provi sion being made for the affected work ers. The turmoil of the period before adjustment, however, focused atten tion upon the causative factors bf'nc-' cupationul diseases and the needed corrective action. Much that 'was done in basic was ill considered and worthless. On the other hand, safety engineers and later management,' be cause of flic expen'eno: gained through this furred .icliou, came to the realiza tion that occupational diseases could lit: prevented and that the cost was not prohibitive. In many awes, oper ation under the improved conditions showed increased profits. Dust is one of the important causa tive agents in the occupational disease picture. Not only are certain types of dust involved in occupational diseases that are potentially m ost costly, but dust in general has a direct effect on efficient operation. Excessive wear of moving machine parts, spoilage of ma terial, and sometimes damage to the finished product are part, of the dust ,,costs that can be eliminated by effec tive control. Another hidden factor is the lessened efficiency of men who must work in a dusty atmosphere, even when the dust is not toxic. The effective control of industrial dust is an engineering problem in which many factors must be consid ered. Some of the most important fac tors are the type and fineness of dust involved and its physiological effect upon the worker. Other points which command serious attention are the type of building in which the opera tion is carried on, the specific oper ations conducted, the machines used, and the physical condition of the worker. Where a new plant is to be erected to fit a definite process, the job of controlling dust is relatively niore Mvi simple than where the existing srfWi ture may not have been designed Jar the present operation. I the fall) case, the engineer must rely mote * mechanical control devices sW y structural difficulties frequently impossible isolation of processes i" arrangement of machines or the -'if*1 duction of improved methods; From the standp m t of physiol cal effect upon the worker's btsF dust may be divided into classes: 1. Those that art. quickly yol .... through breathing, ingeifion, or ijmbh' c* tact. : : : :2, Those which r<-un}t :te- tySteuuV:vilM #ge- over longer jperiod*. o t - l i m m w i ,3>- Nuisance .dusts t^bidr; kmjl JXpwlSft#. k-ss or which may pn.*ibly came slight V j phatoty inflammation, colds, or rvtii p W 'j1 m onk In this latter (lass are irduilid which cause reaction., allergic in which affect only n-viduals who its j tuliarly susceptible lo the particular s'h stance. 4. Flammable dusts, whose itnvvt .'tttremeiyLimporlw'froh} the sbwftattjj fire or explosion, This latter class U"1' many which aie aisi.i members oi the 1 three. Dusts which arc instantly ous are rarely runt with hi inda*1! JVmianal ik/ety Akn'b fflt ^ ^Ibiilhted cases have appeared from;: j^u'nje t time in chemical and pharma/itu tic a l plants and laboratories where J\m ch materials are elements in the production scheme. Their hazards,' * however, are so well known that ade- piotection has long been in *% )led. 'i'he second class, however, is vciy common and consists of the 'mimmotomosis-producing dusts such is rilic a and asbestos;1the poisonous dusts such as lead, radium, manga.jiese and cadmium, which cause sysipr'-'letok poisonings; and the fume dusts ^`surh as zinc oxide, which give rise '$ to a temporary condition known as j * metal fumte fever. Tlie nuisance dusts consist of any dust width does not fall undet the first two classifications but which for f Li reasons of cleanliness, possible respir-: itoiy troubles, and the effect on ; winker morale, should be removed. Where workers are found, to be aller gic to dusts in this class, the only re course so far found to be effective is > m ternove the men from exposure, {since rids grouping includes dust whit h are explosive if mixed in pie proper proportions with air, coife Pul is ill the more important. in tire case of silica and asbestos, the particle size of the dust and its . concentration with respect to the in I P nocuous ingredient of the mass to be moved, are important. Equipment must be selected which will first re- \ move from tire worker's breathing 'ton* the harmful particles and then urap them so that they cannot be re- emulated through the plant, No at tempt is made in this article in dis cussing equipment to specify t h e type to be used for specific exposures. Each dust problem must be studied as a separate case, and equipment chosen which will effectively do the work, The most important element in the control of dust diseases is to keep dust out of the worker's breathing zone and to furnish him a plentiful supply of clean air. Certain opera tions, such as stone cutting and rock drilling, are inherently dusty and can be controlled only by local exhaust systems applied as dose as possible to the area where the work is being done. Small exhaust fans are used in stone cutting and polishing work with effective results, while rock drill ers are now protected with an exhaust cup-like arrangement which entire ly surrounds the drill and covers th hole so that the dust is drawn through a flexible rubber tubing to a point away from his breathing zone. in England, a device employing a suction hose attached to a pedal glove, worn on the hand holding the tube, is used to remove the dust when silica-bearing rock is being cut or dressed. This, while effective hi re moving tite dust, hampers the worker somewhat in his movements. Other forms of exhaust equipment employed for "spot" dost control use flexible tubing equipped, at the on 1 i'Mease turn to page 72) Safety Nett*, Stay, 1939 Tops . View- in iron foundry: slji.v.iivj bench m holers with techmist hotxk Middle ; A amthud of receiving dual into trucks on aU3.ili.ity dioi-collecting quite ment. J.eft: Dumping ground si lieu onto the apron of a conveyor. Note enclosed con veyor exhaust hood ami u*e of approved respirator J,y operator. 19 Awards Show Aviation's Progress in Safety SASSENGERS on scheduled flights For the first time a special sale on the airways of the United award was made to ai division of an States were five times as safe last year air line. This was won by the JRa? as in 1930. ern Division of Transcontinental and This announcement was made March 29 at a dinner in New York City held ih conjunction with the Western Air, Inc., which as a septtr.i* operating unit recorded 151,20U O passenger miles without a passeng . Tenth Annual Greater New York r Safety Conference' at which six U. S, air lines were given certificates of sp cial cnmlriendatioh hy the Aviation Safety Afvard Committee of the Na tional Safety Council for outstanding fatality. The National Safety Council's Aviation Safety Award Commitlconsists of: Harry F, Guggenheim, chairman; Dr, George W. Lewis, viiechairman, director oi Aeromtutk.il .... safely records in the transportation research, National Advisory Comma of passengers. tee for Aeronautics; Col. Edgar S, In 1930 the country's air lines flew Gorrell, president, Ail Transport As 4,000,67$ passenger miles for every passenger fatality, whereas last year this figure increased to 22,308,771. 'Hie companies who received the sociation of America; Edwaid J Noble, chairman, Civil Aeronautic! authority; S. Paul Johnston, editor of Aviation; D . D . Fennell, president certificates of special commendation of the National .Safely Council, and i sn Yr P la n t? j\^/|OEE effective dust control cistt b e obtained b y a daily check of dust concentration in were American Airlines, Eastern Air Lines, Pennsylvania-Central Airlines, Braniff Airways, Continental A ir Lines and Inland Air Lines. The awards were divided i n t o three groups, according to operating mileage. i ln Group A - - lin e s flying more than, 50,000,000 passenger miles an Lew R. Palmer, secretary, conserw tion. engineer, The Equitable Life A> surance Society. Dust (Continued from page 19) trance poiht with various forms n: hopds designed for the partial! yottr plant' D e sig n e d fo r triple, nually-- American Airlines was first operation. Examples of jobs where ; easy operation the B&L D ust Gcnmter aids in accurately deier- with a world record of 410,237,966 passenger miles without a passenger fatality. This record covers a period this equipment may lie encountered are switch point grinding, denning castings, grinding dies, or other jeh. minitiig th e efficiency o f vettti* of more than three years. Easterh Air where portable abrasive wheels or lahiitg system s an d o th er correc tive and protective devices and methods. . Lines 'was second in this group, Pennsylvania - Central took first honors in Group B -- lines flying 2,000,000 or more but less than 50,- dressing tools are user], Most engineers an* familiar will the great variety of applications ni exhaust equipmeht on machines such, T h e B&L Dust C ounter is a com pact portable unit including a 000,000 passengef miles a year. This company in its 11 years of operation has flown 70,159,498 passenger miles as abrasive wheels, gitud-ntones, pol ishing heads, buffers, and other Mrrtilar equipment. Specially designed s a m p l i n g d e v i c e , a dark-field without a passenger or crew casualty. hoods arc fiequently applied to tun1- m icroscope and an efficient illum i nating system . It can.be used any Braniff, which until late in March had never lost a passenger, w a s second in Group B with a total of ,biers, shake-out macfernest sandhlast-'::,!^ ing equipment,: Striibttifig: devic. mixing m a ch in e ball, liftills, grinder1' where in th e plan t. C om es c o m 47,956,58$ passenger miles without shredders and filling machines. Th plete with all necessary accessories in a rugged w ooden carrying case. W rite for details to B ausch 8C a fatality through the years 1932-38. Continental Air Lines and Inland Air Lines won safety honors in the third group -- lines flying less than devices are- mandatory in mosf'Stiiti(iS;sfj||i Properly designed equipment em ployed at the point of Origin of di'-! will effectively rembvh the hazards ' L om b O p tica l C o ., 683. S t. P au l 2,000,000 miles a year. the particular operation.;I t is gen. S t Rochester, N . Y . A special safety award also was presented to United Air Lines in rec ally recognized, however, that id ml dition to local exhausi, a general ven R ognition of "outstanding contribu tilating system that will keep all the tion in study of personnel and equip- , air in the workroom below toxic limits, ment problems for the advancement is essential. There are Several varie of safety in air transport." ties of this equipment on the marl ' all oi which are efficient for the work w h i c h they are designed to do. Mamifucturep# of these systems will, as a rule, guarantee them as to per formance and their ability to meet labor department requirements. Where the building and process are suitable for their use, exhaust fans, strategically placed, may be used to draw air out of the building, through ducts with conveniently located inlet ports, and discharge it into the atmos phere. In esh air is drawn in through vents, thus replenishing the pure air supply. If heating or humidity con trol is not a problem, this method has been found satisfactory. If, on the other hand, the dust col lected from Lhe local exhaust systems and the general ventilating system, are sit;, or large in quantity, they cannot, of course, be discharged into the air but must be trapped. Here, ..devices employing filters of various designs such as bags, filter packs and screens, are used. These filters trap the dusts and prevent their rediculation in the plant through being drawn into the dean air inlets. Filters are frequently employed to recover val uable industrial dusts which would other wist; Ire lost. Sinno exhaust systems, instead of vising filters for trapping the dusts, scrub the air by passing it through water screens, This method works well mi many substances and has the additional merit, where the dust is soluble, of allowing for easy recovery of 1 possible' valuable by-products, llhoe, again, there is no discharge of tonic dusts in the surrounding atmos phere. Electric precipitators have been found useful, particularly where the v. dost which must be removed from the uir consists of very fine particles. These precipitators while efficient in their own right,' may be used in con junct ion with other purifytug equip ment to secure the maximum efficien cy for the dust control system. - The common metbpij of removing nuisance dusts, such as sawdust, is . the local exhaust cfuct which feeds in to a main duct that in turn empties - into baffle type dust collectors, i f the collector is denned- regularly ami there is no objection tp the finer particles of dust being discharged into the suriminding atmosphere, this system will be found satisfactory. Some of the newer dust collector# of this type are -'so designed that even fine panicles HAVE YOU GOT ^0^ :.CoASTEK LIGHTING IN YOUR PLANT ? liyhtiuy fixture# loo fu r'apart, pour duirihuiion u* yhcrw.i it, li, v. op itlusirutian, in the renull.Fpr 6ctri *eein\j vumHliouy, the (Uumiuition in- foote-andUm throughout the. v?ork area shonUI be rmutmably untfonn. T roperly wpaciny the lighttny fixture*, u* #hvwn be/?, rmmtt* in prurito? u n i/or .,,ity. `'p O I .i.g K COASTIR" lighting is X V poorly distributed or uneven lighting. When the amounts of light directly beneath a light sourie end midway be tween light sources vary greatly, you have a lighting curve that resembles a roller coaster with its sharp dips and 'Climbs,:'.: .The extreme contrasts chat exist be tween bright and dim areas may cause eyestrain . . . slow up production . :... increase operating errors . . . and con stitute accident hazards. Seeing is dif ficult because workers' eyes af con- tinually trying to adapt them selves to the m any: lig h tin g c o n d itio n s in the w orking area. In general, direct lighting units should be spaced no further apart than ilu-ir . h e ig h t . -------c > -* " above the (loot. W* h* tfrrsev supplememary lighting is acquired, general lighting should also be used. Write General Electric Co., Dept, idNS-E, Neltt Park, Cleveland, O., for the new booklet, "righting for P roduction in the Factory.'' GENERAL H ELECTRIC MAZDA LAMPS They stay brighter longer J do not escape into the air if the equip ment is properly maintained. In existing buildings, mechan ical removal of dust by means of ex haust systems, is probably the most i effective means of control, although j there ate other points of attack which must not be neglected. Housekeeping I is extremely important. Much can be done to eliminate a dusty condition j by care in handling materials and by j establishing and m a i n t a i n i n g a ! thorough Housecleaning p r o g r a m , j This may entail the brushing down ; of walls, cleaning of ledges and beams; dusting of machines, and re- | moval of dust from the floors at teg- ! uiat intervals. AH of this can be done more efficiently by the use of built-in vacuum cleaning systems or by port- 1 able vacuum cleaning outfits. Rc- 5 gardless of the means adopted, the j cleaning should be done frequently : enough that there is no possibility of ! vibration shaking the deposited dust, ! or drafts blowing it, into the workj room air. The isolation of dusty processes, either in separate buildings or de partments, has been found satisfac 1IIEH tory, Where this isblation exists, it ELEVATORS is possible to reduce the installation: WILL1BTFALLEVERIF costs for exhaust equipment which, of course, means that operating, main- i MILES BREAK ; tenante and replacement costs are Like 36 magic, :carpet of ancient j lessened proportionately, mythology.; > M o n tg o m er y Elb- j Enclosing dust-producing machines VA'roii whisks yd from, the street ! and material-handling equipment off- level to the top of the highest build | ers another means of control that is ing. But anlrk the magic carpet, m odern elevator cati'l: suddenly drop you down front: th e heights. Why? Because a safety, , device a u t o m a t i c a l l y -previaifh th e car from fallin g even if all tiro cables should break.-.. There's ttp m agic h e r e . . . just good Bound e n g in e e r in g , Mont comem hag-alwtiyn been prom inent in the development of elevator safety devices. -That is one o f the reuson for the w ide spread, 'accep tance of MONTGOMERY ELEVATORS toilay! : receiving much attention. Machine manufacturers, realizing the demand, are designing to this end. Tightly fitted covers on mixers and tumblers, i ,dust-proof joints ori conveyors, and | fully enclosed machines are examples j of the good work, done in this field. Exhaust systems built into the ma chines are becoming more common. Wherever possible, buildings should be designed for the operations to be conducted. This entails the us of enclosed operations wherever pos sible, provision of ample space to pre A sk Us for Help with, Any Elevator Problems vent crowding, isolation of dusty equipment, and design of the building to facilitate good housekeeping. Bev elled ledges, rounded comers, enclos ure or bevelling of exposed beams, and the installation of built-in Mwtnftorturers o f (ttl Types o f Elevator# IMOIWE O FFICE AND FACTORY IVIOIJME, LUNOIS fituiwli iIMvw avtf Abmv in Principal Osistrt vacuum cleaning systems, are possible when the building is. properly de signed. Like the housekeeping program, j i . f . .. ..j . _ ,, - . i u _____ . . t 4 ^ - -- tabled at a high standard to oi'tr?1-* at maximum efflceney, ducts reduced in area by heavy posits of dust, wheiher Harmful r merely nuisance dusts, lose their effi ciency. Regular cleaning prewar'11 should be in eSect, and air vtlreiiy readings should be taken at exh-uai hood inlets to deterrvne the flpend!'>| condition of lhe equipment. Any dcviation iron) standard teqairejnepW should be checked at once. It is * sad commentary but true that many thousands of dollars are invested in exhaust equipment that mlgh1 1 1' have been spent elsewhere su e1p.'"" maintenance has rendered if practk1 ally useless. Air tests to determine the cono*tratiou of harmful dusts should hit made at regular Intervals by qualified engineers. These tests ahmiht hi made even though velocity test* ^ the exhaust equipment indicate tbi|it is operating at maximum chit m-v Leaks in ducts may be pouring dust lizb'k into the work own and times these can be discovered onh ht careful inspection after high dust cm centrations are discovered, New npsr' ations may be added, or machines r_ arranged, so that original velucites(i; air become insufficient to remove Ik* dnst. Air tests will reveal this cot'irii* tion, Where air tests art1made al tegulyf intervals, the expense is often ; ! fied by the maintenance of higher em ployee morale. Also, any indicJdM of toxic limits can be corrected beite workers are affected and become sub jects for medical treatment and pos sible compensation. T h iie me several nfhri methyls dust control that have proved ,(| live in cases where they Could he im plied. Substitution of innocuous me teriais for 1oxic substances, use of wrj processes, and the application d binder dusts to "lay" the toxic dusts are common. In many cases, lemever, these are not practicable and <<' course must be had to the methods al ready covered. Or Should Be Safe drivers are now1handsoi#S)!:;j rewarded by automobile Itisutawc companies with premium rebate, However, escaping from the corenw represents at least one-ease whHitvb tue is perfectly willing to lie its ow, --- . . >1 4 {T|*. .