Document dn4mYkGGoq1ozqvy6Ba3nEvjq

FILE NAME: Caterpillar (CAT) DATE: 1963 DOC#: CAT005 DOCUMENT DESCRIPTION: Published Article from National Safety News I H lo w do you get. too per 'cent of you/ employees to wear /cry shoes when eveo with a steady pro* gram of safety education they have avenged close to only 50 per cent over die y e a n ? ' Joliet P u ts Department of Cater pillar Tractor Co., Joliet, HI., showed the way In an intensive one-montH foot-safety campaign in June 1963. With teamwork and enthusiasm, the 315 warehouse employees zoomed tHelr avenge in ooe month from 54 to 100 per cent coverage'. it didn't just happen.. Behind that one month's effort was serious plan* ning that resulted in a program jolptly prepared and carried out by management and employees. Plans actually began' to crystal line last Januaty when P am Stores Manager Bob Shoopman reviewed .safety. records. Severity and 'fre quency had been at ell-time lows during the previous year. But what concerned him was a bill for 591 for one foot injury. He was sure the injury could have been prevented by safety shoes. It meant not'only a cost* of operation, but more than that* a degree of human suffering and inconvenience! Why didn't em ployees take advantage of safety shoes when they were conveniently, available at cost through the safety 1store near the cafeteria? Shoopman asked, foremen to sur vey their men for reasons they didn't wear safety shoes. Answers* were typical; "Safety shoes hurt my feet." "Safety shoes are too clum sy." "I can't afford them." "I don't need them on my job." All were honest problems to the men, Shoopman realized, and the next stepV as to solve them. How -could'they do this effectively so all employees would benefit? The , Parts Department Safety Committee of key management and union agreed that an intensive foot Safety education program might be a solution. The idea clicked so well the union representatives asked that their Ports shop stewards also hear about it. Out of the meeting came the specific plan to point up Juae|as "Foot Protection Month." The planners also agreed that they should be ready with answers lo t all foreseeable- objections to wearing safety shoes. There should be awards for outstanding partici pation by individuals and groups. P a m Department Manager Bill , Oedewaldt announced the cam- i paign is a letter sent to all emt , ployees' homes May 22. The BuR- dozer, the Joliet Caterpillar Plant and Parts Department newspaper, gave the drive a full editorial senoff. Union* leaders urged support of the month. While the planners may have had an ultimate 100 per cent goal in mind, they aimed initially at inform ing every employee in as many ways as possible about the value of foot protection. They hoped to make each employee aware of dangers to his feet in on operation in which employees handle thousands of heavy p y ts every working day. This is bow the careful planning paid off: To prove that safety shoes aren't hard to fit, they brought in a rep resentative fronj the shoe vendor to spend one full day the first week specially fitting ail problem cases. 'And there were some very real prob lems; One employee needed a tree lOVff for one foot and a size 12 for the other. This required a speciallybuilt split pair. They answered complaints that safety shoes were awkward, clumsy, - C.L A .Ammat M i Ami ihwh*u I/ A St I Injvnf fh| Mt MmdtawAt wand*ring abavt h*i E fin a W . TW vpf4|ht af a lark tram * tohJ.fl Imck tail a v a r W i Mat. and unattractive( by setting up a display of aU types of safecy'shoes -- including pahs Indistinguishable from the best dress shoe. They moved the display to a table em ployees passed every day going to and from lunch.. They answered-the "too expen sive** charge by pointing out -that shoes average only S9.45 a pair and can be bought on*a regular .sched ule of payroll deductions. They also t pointed out that a pair of oxford- ' type shoes can be worn off as well as on the job. The idea jelled. One employee even'wort his safety shoes to church, "f need them for all the people passing In and out of the pews all the time." be quipped "They're good looking enough to wear anywhere." There was competition among the 10 warehouse foremen's groups. Each group gave itself a nickname such as the Chubby Checkers, Kite Owls, Toe Savers, or Woodchucks, On a 42 by 36-(nch bulletin board ' set up in the cafeteria, each team, was listed on a blue silhouette safe- . ty shoe that was moved daily tow ard' the 100 per cent mark as Us partic ipation increased. As incentives, the company of- fered a handsome quality ballpoint pen to each man on every team that reached 100 per cent. In addi tion. safety seat belts,'installed, were the weekly "award o f recognition." The winner's aame was drawn from u. JlA COMf o t p fttw H tli * I WMUf dr*irifl( it* otMr * f Mf Mfh taWIK**) *n if fw f'i 0*df**I, |Mrti rfapoffMMt m ( h, haJdi b** for fte*r Meo, pr**U*<V, M f t U1. Mtirfcr U . AworioKoA W UtctilMin. ATL Im Uaq * to l*lo* o*d wfity Mpr*Mtoti*L ` th r ift, *afotf In rftH faU r, *4 t* b h i a p a iiy p v l i m i All rfc* *Ur wfcnw* m t wMrfttg n ifty Aw i ton M r m m i w ttt drawn, and datmd rf* prfi, Otter Ineontfm ladvdad taApolM pt<* tor mm m Wont rfcr r--dtd 100 p tt out, t*4 0*Un A m Club word carniiHup *1 ipMal llfluto arid paid WM pJ"> a box containing -the names of all warehouse employees. The only stipulation to claiming the priac as that the winner must be u earing safety shoes when his name was drawn. (All four winners were. I With the cooperation of the American Society of Safety Engl* neers and the safety shoe vendor, the Parts Department set up Golden Shoe O u b awards. Every man whose feet were saved by safety shoe' protection was honored by a special certificate, a gold lapel pin, and his name inscribed on a gold plaque. Every team area set up its daily score of participation;. Each fore* niW s desk carried on 614- by 21iaco National Safety Council foot safety poster. Department bulletin boards displayed a weekly foot safe ty message from the department's safety mascot. At the main employ- As accident n te i riie, to do easts. And no plant, large or small, can afford Jthar, or btllava Insurenee "cover* everythin*" . Beyond Insurance n te In* ersasos ire the "hidden" CUT costs. When worker* stop to help,, machines He idle but YOUR w ages continue. Output tails. Overtime may result. COSTS AND Machine damage or materiel loss can take place. ACCIDENT Q ranet coated fabric [loves alone won't do the RATE. . . frick...so that's why we In troduced a completely pack* aged Accidant Prevention WITH A Program. According to the . National Safety Council,hand, .finger and arm Injuries repre GRANET sent 36% of Industrial ac cidents, account for 29% of paid out compensation. HAND Such a Program in your plant wilt increase risk awareness, promote ell types SAFETY of sefaty. Write today or phone ypvr Granet Distribu tor for your fme Hand Safety KH. It Includes samples of PROGRAM! postars, bulletins, decals and names of leading com panies conducting such pro grams right now. GRANET*CORP./22 lertng Drive, Framingham, Massachusetts ru e c u w t* that rrr u * c a c to v t citen u oh maoii caso N infosi Safety News, Meamfcer 19*3 ccs* entrance, the big safety sign-' man viewed the record aa a con board read: " Foot Protection Month -- Let's AH Make It a Success." stantly moving target to keep bitting every month. On the third of June -- the month's first working day -- all emr ployees saw a foot safety film. As they returned to their areas they received literature on foot safety, and a free pair of shoestrings "for their safety shoes" from the shoe vendor. ' It wasn't long until the competi tive .spirit began to get participa tion moving in earnest. *1 wanted my team to be lint," said Chief Steward Don Williams. " I eves got permission to botow the safety shoe, What effect' did the campaign* have on employees? Listen to re actions a month later: Chief Steward Don Williams: "I t . was the best safety Idea I've ever seen put into practice. Every man participated. I think our people are impressed with our record and are keeping it up.n Material handler Jim Wisdom: " I lost the nerves in my foot from a foot accident; 1 was sold on safety shoes before and m keep trying to * sell other employees on them." catalog to show fellow employees Tom Berrong (whose power how good looking safety shoes are." truck r a a , over the toes o f one of ' " th e employee enthusiasm frooK the Golden Shoe award winners): the start was the most encouraging v " I think our people now are well sign' to u s/' said Parts Manager aware of the need to wear safety OedcwaldL "We had realized this shoes' all the time on the job -- was going to make or break our cam no< just for one month to set a rec paign," ord" Teams vied for the honor of Foreman Clyde Cheooweth, a 33- reaching 100 per cent first Don WiLUiras did bring his Processors -- year employee, said: " 1 don't think the enthusiasm faas died down a bit. 28 men.--- i n first As pressures within each group increased, others After all, the men themselves con vinced each other of the need, and followed suit Even the Toe Seven, everybody's been wearing them who Had started out at 30 per eenl since the campaign closeId." (lowest among the teams), .moved Since employees went; on vaca into the IOO per cent spotlight by tion the first two weeks in July, the third week. By the start of the Farts M anager Oedewafdr seat final'week, 315 men were wearing safety shoes and sporting a band- some ballpoint pen that acknowl them the traditional letter of "best wishes," This time it expressed his appreciation for their exceBeotsafe-* edged their p a n in success of the ty. record on the job and the hope one-month drive, they would return safely to the. job Enthusiasm by the fourth week too. Enclosed was a brochure on had readied its peak. The spirit vacation safety hints. was so .contagious that .the office based planning group that regularly works in the warehouse ares had also signed up 100 per cent. Even Employee Relations Manager Gerald Plan k / of Joliet Plant, who had admitted doubts about the ef fectiveness of "gimmicks" to stimu I te e in l u n u J* o p Fm i Nm F w A( ?/ . 4 td d * * ii I m i m U m k th tp A m M m Mi Im i wyiftf I* i*U tS w m Am i --MettfHl MwWtw J la WWem employees from other divisions of late participation in such a cam the plant coming to and from the paign, quickly acknowledged, 'the warehouse joined the parade of worth of the one-month drive with "&afety-shoed" ;m arcben. this observation: The management group knew en ."The spirit of success for any ef thusiasm 'could wane if the cam fort has to originate within tbe em paign suddenly stopped June 30. In ployee group Itself. Enthusiasm is addition to continuing the program contagious and must be started by of Golden Shoe awards, they" de the top man and carried down rided to keep the team standings through the organization. U must, posted every Week In the cafeteria therefore, originate within the to extend the spirit of competition group. By knowing their own people . among the teams. They agreed to and carefully planning In advance. keep talking foot safety at every op Parts Department, through Us safe portunity. ty committee, proved it could gain Parte Stores Manager Bob Shoop- their wholehearted su p p o rt/ 4 XroAm Tm l t u>n - Kattml SffrtrMmiOKtobarlttt . 1 i 37 r i* I 26 Metals industry lion up to one-half to three-quarter mile radius. It seems likely that this anil be modified as data accumulates. The medical control of beryllium poison ing involves careful pre-placement examina tion so that no vorkcr who has had previous chest disease o r unusual x-ray findings would be placed in a job involving beryllium expo sure. From what IVe said obviously anyone with previous beryllium disease would not be allowed near operations involving further exposure. W e have teamed that loss of weight Is one of the early symptoms of beryllium effect, so in plants that must use beryllium the workers are weighed at regular interval* such a* once a month. At this time the physician or nurse who sees the worker can decide whether o r not weight loss if it is present is important or related to the worker's job. Chest x-rays are taken if weight loss is persistent and in all cases a t least once and in some instances twice a year as a kind ox check up. I think it is a mistake to be over-anxious about medical scrutiny of these workers on the one hand, but on the other hand l think steady, conscientious observa tion of the workers* general health corre lated with what is known o f the character of their exjofure can be very reassuring and doubtless will result in the disappear ance of cases, certainly of chronic beryllium poisoning and one can hope as operations are made safe, acute beryllium poisoning. I would like to close with a land of teach ing warning to this group asking that you be j careful to interpret correctly what is now i appearing in the literature in regard to ill- ness following beryllium exposure. For a ! long period of time nothing appeared in print while illness was being experienced in industry' hut now we have a great flood of literature and for the most part it is conscientious and helpful. However, for various reasons that arc complicated, front time to time there appear articles suggest ing that this great discussion of beryllium toxicity is without foundation. Unfortu nately, this sometimes seems to be related to the interest of the author and for those of us who are professionally interested in the prevention of illness in industry the read ing of this material must be undertaken with critical judgment. f am sure you agree with me that there isn't any hazard in nil of industry that can't be met if one Is willing lo make the effort and so it i* not necessary to whitewash beryllium, to use a catch expression, but it is necessary to accept its toxic possibilities and take the necessary engineering and medical step* to anticipate possible ill effects. Safety in M aintenance By F. C. GEDGE P lan t E n g in e . Caterpillar T rac to r Co-, Peoria. HL All men at work in industry are subject in the common luizards of industry in gen eral and to the specific haard of their particular surroundings. So here are the principal factors in the pursuit of safety: Ut.--A careful man. 2nd.--Sincere and competent supervision. 3rd,--A decent work place. 4th.--A voice in the program. 5th.--Proper toots. And what are the A -B -C s of safety? Always he careful. Regardless of all other factors this is the essence. The man him self is more thnn half the total of the sum that equals safety. He must be healthy, both physically and mentally. A fter his appli cation for work is recorded through a sta tistical report and before induction to the plant, the firM procedure is physical exami nation. Minor defects should be corrected Vision checked and if prescription safety glasses are required, a fair part of the ex pense borne by the employer. The doctor must be sincerely helpful -- not a critic. Adaptability tests and interview to deter mine menial aptitude and attitude are equally essential. It pays to spend two day in a proper study prior to putting the new man to work. This on the company time-- not at the man's expense. If then he is healthy. and if he fits the needs of an open job, then take the time to conduct him through the plant Safety in Maintenance 27 Let him see what makes the wheels go round: what you produce and with what land of men. Tell why you have a right ;o a market and how* you -hope to continue to supply that market. W ith this done then take him to the supervisor with whom he is to work. That supervisor, ot course he has already met in the preliminary interview with the personnel manager at the time he applied tor employment. This supervisor will show* him where he is to work. Introduce him to die men he will be in immediate contact with while at work, show* Him where the tools are kept and how* to get them, where his locker, toilet, washrooms and cafeterias are located, and do all this with friend* liness and without haste and in a manner that does not confuse. Again, this is the essence. Do you expect a man to be careful if you, the employer, are not careful in his selection and consider ate of him during this, the most critical and difficult time of his employment ? Say you'll grant this. Now he is at work. Be sure he is placed with a journeyman ifince here we are dealing with maintenance :mde* work) who is an extrovert, a sales man. Salesmen loiow their way around and they like people. He will sell. SHI the plant, the supervision and the job. Sell the new* man the job and you sell safety. Safety is sold by practice, nor by books. The supervisor is the management as far as the workman is concerned. He must taiow* this himself or there is no sale in the long run. He must spend his time super vising--not doing the work, writing papers . r attending meetings. These two latter Hems are necessary* evils. I f a check indi cates the supervisor is spending more than 25 per cent of his time a t them, do not expect good supervision or full practice of safety by the men. I f each supervisor has not time to talk with each of his men at least twice every day he cannot control the work nor guide in the observance of safety. And while you are looking over this angle take an overall look at your theory of super* vision in maintenance. Industrial plant maintenance is an out growth of construction trade labor. As the American industrial system grew we saw a rapid expansion from the small, individually owned, built and operated fartojy to the larger complex mass production type o f in* dustry Instead of the handy man type of maintenance we introduced the tradesman-- carpenters, pipefitters, millwrights, sheetmetal workers, electricians, etc. Each tended his last and the best man usually advanced in the ranks till he became supervisor o f that trades w o rt The coun try and industry grew* rapidly. W ith it, if the business served legitimately, the plant expanded. As more space was covered, the more machines and men w*ere put to work. Likewise the maintenance requirements in creased. H as yours increased to the point where the maintenance trade foreman spends too much time running from job to job rather than running the job? H so can you expect real safety? Should this be the case, consider revamp ing your system to that of area control rather than trades control by trades fore men over the whole plant. One maintenance supervisor should better be responsible for all work and mainlaiance workmen in a suitable sized area rather than a trades foreman be responsible for all trade work over an entire planL The area supervisor should be officed in his area within close reach of the production management of that area. He still should report to a main tenance engineer in charge o f maintenance of the entire plant and he should draw* his men from a common group under control of a maintenance shop superintendent, who in turn also reports to the maintenance cigincer. Such a method o f area control re duces the maintenance supervisor's leg work, lets him be with his men and their work almost constantly and takes big out of big business. The trades knowledge had better be placed in the maintenance shop foremen and thus permit the area supervisor the time to concentrate on his ability to get along with people and in turn by close association with the area work to get the m oi along with the work. H e is thus the only* boss in that area as far as maintenance is con cerned and is in a perfect position to get done what needs to be done a t a proper time and so avoid delays and duplication of supervision which so often occurs where responsibility is split. W ith sole responsibility* for the mainte nance of a definite area the supervisor, since he sees alt of that area every day, can that give proper attention to the physical condi tions of the property and hence develop a deceit work place. This is important to 28 M etals Industry Foundry B y p en t 29 safety. I f the shop is dean, the roof U tight, th e lights are sufficient, the wiring and piping are standard, the machine areas and floors are clean and smooth and there is dean a ir to breathe; then the setting or needless acddoits is automatically removed. Certainly the figures prove cleanliness breeds goad safety records. A further benefit to be obtained by area supervision, important to safety, is that by daily familiarity with the physical prem ises and full knowledge o f job progress in each rase, the area supervisor is in the best position possible to protect his tn si from location and process materials and practice ho ard s. H e knows what dangerous chemicals are used, if any; what power is present and w here; which are steam, water, gas. oil o r air lines and where to shat them oft. H e knows where cranes are installed and what they lift and countless other details only to be known by constant daily association w ith his area. Knowing these things automatically places the area supervisor an a competent position when inviting the full cooperation of all maintenance w orlonai in the safety pro gram. Bet your bottom dollar if your pro gram is not based on the participation of the men in the forming and constant revision of the practice of safety*, your frequency rate not your profits are doe fo r an increase. Safety is taught by practice, not by books. The practice is formed by the men perform ing work properly. Vv"ho then but the men can be the promulgators of methods. The supervisor is the interpreter, he asks the man what is required to make this job safe. H e can aid the man by pointing out what made the Ia n job safe, but this is only an aid-- a reference to precedent The man must tell the supervisor what he thinks the job re quiiements are and then they cm work it out together, beforehand. The Army Air Force did a good job a few years ago by the use of this method in their practice o f "briefing the crews" in the ready room before each flight W e in industry should do likewise. It takes but a few minutes to discuss the job. on the site, before the start of work. For instance, how do you otter gas filled rooms? W ho supervises unloading of tank cars of I*. P . gas, adds, etc. W ho super vises electrical construction projects and if only one person is so qualified, what do you expect to happen if he gets hurt? This ii the tune also when the m atter of proper tools should be considered. T he use oi proper tools is *definitely a part of a well rounded safety program. However, the years have taught--even with the best tools, the safest tools and best possible tool mainte nance in the world--that frequency rates will still climb unless the man who uses them, the supervisor who guides him and the plant in which he works all form a canbination in which safety thinking can dwell in safety. Industrial safety found a beginning in the early 1900's, here in the central w est The original effort was directed towards elim ination of mechanical accident hazards and hand tool accidents. The effect on frequency rates was a bitter disappointmsit and the hullabaloo that accompanied these campaigns backfired, with the resultant creation of the cynical attitude on the {art of the worker, which. lives even today in many industries and amongst some labor o rg a n iz a tio n s . However, though least important of the principal factors in safety, tools must be kept safe. Those bearing the closest scrutiny a rt: _ (2) Personal Tools. It is common prac tice for each maintenance worker to proride the ( small tools used in his trade. Screw drivers, hammers, pliers, chisels, ad justable wrenches, etc, arc usually purchased by the employee as he finds need fo r these A . periodic inspection by a member of the safety committee in the course of a day's work is usually sufficient to remind the owner when repairs or - replacements are in order. (2) Special tools o f the larger more sel dom used tu rifty such as sledges, moil points, jacks, large pipe and m achine wrenches ere usually company ottmed end mode available by the tool crib. Their proper maintoiance is a function of the crib tool dresser. These tools should be issued on tool checks only; hence their pe riodic return to crib a t completion of that job affords opportunity for ample periodic inspection and repairs. (3 j Ladders ere dangerous tools. It is amazing to find an culling over the old records how many accidents involve this most generally used tool. Maintenance of ladders is a subject often under dispute. Actually the proper procedure must be pat terned to suit your own shop conditions. It is our practice to place ladder order through carpenter shop supervision. Upon receipt, they inspect for quality, particularly 55 to density, grain conditions and tightness f assembly. The rails are then primed ttd painted. Each trades department has ;& own number and their particular ladders receive a specific color paint identifying em as belonging to millwright, electriaan ;r other trade department as the case may te. This prevents general usage by all :ntdes and helps to place responsibility for proper keys and usage with a particular ,,Tulip. At the end of a job ail ladders are re tamed to the shop storage rack and there inspected by the shop man responsible for -heir upkeep. The workman using a ladder if instructed in safe ladder practice white till an apprentice. H e is taught the allowiMe angles, how to scat the pads or spikes. to mount, and bow not to over-reach md how to carry. It is amazing how much the men can teach you about ladders. To* .in? this subject in a safety committee netting, assuming your workmen have full representation. The use of signs and guards in and irouml arm s under conn ruction or repair t another practice that warrants study and -hecks. I am reminded of an accideit in vhieh the workman, engaged in floor block repairs plaeed a sign ahead of the job that read "danger, workman above." The trac tor driver approaching saw the sign, looked above and seeing no one detoured the sign and struck the worker on the floor ahead of him. Another pitiful case. A sign on a door lintel of a door opening onto a plant highway--"watch out for trucks.** A fore man of 30 years' experience, saw a truck approaching from the north, stepped into the roadway with his eyes on that approaching truck, directly into the path of a second truck approaching from the south. These accidents are typical, not of the fact that signs are bad, but that we often misread their meaning or in some eases misuse them, The tendency has been to ward the use of too many signs and w arn ing signals. A review is often interesting In what It wilt divulge. Have you seen the color red used to fire protection cquipmeit, water pails for instance, and in the same locality bright red cans marked gasoline ? These few statements of practices and in cidents are but a small cross-section of our own particular plant and practices. They have but this one thing in common with the practices tn all industry. They teach tliat true safety depends not on one or a dozen factors. Rather to go back to the beginning of this subject, a careful man, properly supervised in a factory that is dean and bright, with a voice in the program that means safety to all, and given the proper tools with which to work, all this is the sum of maintenance in safety. Foundry H ygiene By JAMES F. MORGAN Chemist, Industrial Hygiene Foundation, Inc*, Pittsburgh, Pa. Although recognition of the faet that there is a silicosis hazard problem in foundries am e many years ago, there is a continuing seed for more precise means of evaluating t hazard. Throughout the years, dusti ness in the foundry has undergone a steady reduction, chiefly by eliminating the most abvious sources. Replacement of natural stone wheels with irtifirial non-silica abrasive grinding wheels, thanges in sandblast techniques, widespread substitution of non-silica parting compound for tripoli and mechanization with built-in exhaust systems have all contributed greatly to a reduction of the hazard. Nevertheless, the fact that silica sand remains as one of the basic materials of foundry operation demands that the inherent hazard be recog nized. understood, and controlled. The complexity of the problem o f evalu ation of a silicosis hazard in foundries can be illustrated by a comparison with that in granite cutting. In the latter case, the manu facturing process is essentially dust pro- 30 M etals Industry during, in which the parent n a te m i, sione is violently broken down imo dust of approximately the same composition ; the foundry processes are in most cases dust* dispersing as in sand cutting and molding, rather than dust producing as in sand-chip* ping: in addition, foundries have the com bination of the two in sand-blasting, lite result is that in the foundry the aire-borae dust shows great variation m composition related to particle size from place to place. This complexity and variation in foundry dustiness is reflected in the results of sili cosis case-finding surveys in foundries. The 193$ New York state study disclosed sili cosis In 2.7 per cent o f 4,000 workers ex amined, with wide variation in the incidence between different occupational categories within a foundry. North Carolina, in the same year, discovered silicosis in 1.3 per cent of 680 workers examined; total dust pathology amounted to 9 7 per cent o f em ployees. This study also disclosed some sur prising differences in the rates fo r different occupational groups. Sander, in Milwaukee, in 1939, found silicosis in 5.8 per cent of 8,377 workers examined. Variation between occupations in his study ranged from 28 per cent incidence among sand cfaippers and grinders down to 0.1 per cent in corcmakers. There are several obvious reasons for attempting to evaluate the silicosis hazard for each occupation in the foundry. The physi cian needs an adequate description of the dust hazard in order to diagnose Illness and assist in proper placement o f workers : management needs evaluation in order to plan and design control measures a t the necessary* places ; in routine operation, main tenance and utilization o f control measures have to be judged by effectiveness tn con trolling the hazard. Four factors have come to be recognized as influencing the significance of a dust exposure. 1. The concentration o f dust m the air in the working environment. 2. Duration of the exposure. 3. The chemical composition o f the dust. 4. Its effective particle sice. J. The concmlration o f dust in the air-- The determination o f the concentration of dust in the air by means of the dust count is such a familiar procedure that it hardly need be mentioned here except in its relation to the other three factors. I t is a valuable first step in the appraisal of a dust hazard. By means of it we obtain an index of dustiness of a given environment at the different steps in a process cycle. On infrequent occasions, the dust alone can be made the basis for i recommendation that dust control be in* stalled Such instances are those where a massive concentration over an extended penod o f time creates an undesirable situa tion regardless of dust composition. Most often, the dust counts are useful in comparing lesser exposures with data for dust in other situations wherein the health hazard has been adequately defined. In order to permit such comparisons, even though the values obtained are not absolute, but arbitrary --depending fo r their magni tude on the manner of collection and method of counting--the technique has been stand ardized. The standard procedure of counting at. tempts to hold variation of particle size a a constant by defining the limits of the m et which shall be included in the count. This succeeds only partially because particle size distribution curves vary with different types of dust. fn making the most common use of data from dust counts, the comparison with other exposures haring known effects on health we must assure ourselves that we are making a valid comparison by investigating the com position of the dust 2. Duration o f tTporurr--The influence of exposure time on the evaluation of a silicosis hazard refers to the acttal time per day spent in the dusty environment, or con versely, how much time per day the dusty phase of a given job lasts, Study of the actual operations and surrounding opera tions to r each foundry* job is necessary* to clarify this part of the total evaluation. 3. Composition o f dust-- The necessity for determining the amount of free silica in various size fractions of air-borne dust, in order to evaluate the foundry silicosis haz ard, was pointed out by Hatch and bloke, in 1936. They* showed the error of applying the quartz content of a settled rafter sample o r the bulk material from which the dust was derived to an evaluation of a silica hazard. Unused molding sand contained 65 per Foundry Hygient 31 cast quartz m the fraction consisting of particles greater than 10 microns. 27 per cent in the 5 to 10 micron fraction, 19 per cent m the 2 to 5 micron fraction, and 18 per cent in the fraction consisting o f less than 2 micron particles. Compare this with an analysis o f air borne dust from the breathing zone of tnoiders ut the same foundry* 3*. 36, 20, and 12 per cott quartz fo r the comparable site fractions. The explanation fo r this variation in quartz content with particle size is that sand conditioning and molding are not dust-produdng jobs, but rather dust-dispersing jobs. The molding sand consists of large particles of q ta rtz sand surrounded with clay o f very fine particle size plus possibly coal and oil. Analysis of the gross sample shows this high free-silica content However when dis persed in air, the coarser quartz particles settled more rapidly, leaving the air-borne dust relatively more rich in the fine d ay and combustible matter. Air-borne dust ia the vidnty of shakeout operation shows a similar decrease in quartz content with decreasing particle size. So do the other important dust sources: me chanical cleaning of castings, sand chipping, sand-blast, and the general foundry air. This study revealed that the true dust produdng operations of sand-chipping and sand-blasting in which particles of quartz are actually broken down into finer par ticles resulted in a high quartz content in the finer fractions of air-borne dost. More than 30 per cent free silica was found in the less than two micron fraction of each. Comparisons of the incidence of silicons among the foundry* occupations tend to re flect the relatively greater hazard o f sand* chipping revealed by these dam. Unpro tected sand-blast is more rarely encountered and has not been included in the tabulations to a sufficient extent. Data from Industrial Hygiene Foundation analyses of foundry dusts show avenge free silica content o f total air-bom e dust of shake-out, core room, and molding, to amount to 29 17, and 16 per cent by weight respectively. The less than five micron frac tions of the same dusts showed 8, 10, and 4 per cent. ** Recently acquired data in a Foundation study of eight foundries making a particular type of light iron casting showed that a ir borne dust around molding operations con sisted o f 3 to 15 per cent quartz in less than 3 micron fraction and 2 to 6 times as much in the fraction greater than 5 microns. Analysis of the less than 3 micron fractions of the mold sand itself showed 10 to 30 per cent quartz. The recent study o f Illinois foundries by U .S.P.H.S. showed an average of 75 per cent free silica in the total mold sand. The Industrial Hygiene Foundation now makes it a routine practice to separate dust samples into two size fractions at the 3 micron level, before determining free silica by x-ray diffraction. This placing of cmpliasU on the necessity for making separations into several size fractions before analysis to help determne the existence of a silicosis hazard is, of course, based on the evidence that the larger particles do not enter the depths of the lungs and do not contribute to lung pathology. There is another reason. Hamlin has re lated that experiences over a number of years with foundry grinders and burners showed that diffuse nodular shadows occur in roentgenograms of the chest. These are shown on autopsy to be caused by deposits of finely divided iron oxide. The condition is apparently non-disabling, non-progressive, and does not enhance the progression of superimposed infection, yet. it can be mis takenly diagnosed as silicosis. In order to make a diagnosis, a physician will want to be supplied alt the pertinent facts concern ing a man's working environment and his tory. H e cannot depend on roentgenology alone. If the fine fraction o f the dust to which a man has been exposed over a num ber of years is rich in iron oxide and lean in free silica, that is a pertinent fact that should be supplied the physician. In a 1047 paper, Holden, Hemeon, and Hyatt, o f Industrial Hygiene Foundation, describe a technique for collecting air-borne dust in amounts sufficient fo r analysis, and a method fo r the routine separation by sedi mentation into two fractions a t the 3 micron level. 4. tnfium ec o f porfele rise -- In enu merating the factors that influence the sig nificance of a dust exposure, effective partide size was mentioned This is probably the most complex and least understood fac- $z Metals Industry tor an the list. For its consideration, let us put aside fo r a minute what has just been said about variation o f composition o f a dust with variation of panicle size and think of a dust of uniform composition. A certain amount of this dust will consist of particles too large to get very far into the respiratory system o f a man before it is stopped by the hairs of the nose, the moist surfaces, and the cilia in the bronchi--all o f which tend to trap it and prevail its inhalation to the deeper passages. The smaller panicles, ranging downward from, Jet us say, 10 microns to 0.1 micron o r less, unit be acted on by several influences! they will penetrate, to an unknown extoit, the deeper passages to the alveoli; they will be wafted in and out of the ilveoli with cadi respiratory* cycle, bring deposited to an unkown extent; and finally, at least in the case of quart dust, they* will exhibit toxidty to a varying and unknown extent, depending on their size. Penetration, m e n tion, and toxidty as related to particle size are beginning to be recognized as having fundamenal importance in activity* of dusty panicles. Active research programs are underway today to improve an understand ing of these subjects. Hatch and H emeon last year reviewed the questions of penetration, deposition, and toxidty oi dust in the lungs. They con* strutted a curve, based partly on experi mental studies of retention of dust in the entire respiratory system, and partly on theoretical considerations, which suggests that `"there is a given particle size having the greatest probability o f bring deposited in the alveoli and that the chance of such an event occurring falls off rapidly for par* tides both larger and smaller than this optimum size.** An extension of these considerations to include the qualitatively demonstrated fact that toxicity increases with decreasing partid e size leads th a n to construction of a curve representing relative toxidty per unit concentration of inhaled dust. The sharp peak o f this curve suggests that damaging capacity is very sm ritive to particle size. These interesting suggestions were pre sented by them to point out that although panicle size is not generally taken into account in appraising dust hazards, its influ ence may be very g n a t Research on the relationships between panicle size and pene tration, retention, and toxidty is now bring pursued and has begun to show in a pre liminary way that the peak on the deposition curve of Hatch and Hemeon lias a basis in fact and is fairly close to the correct nu merical value. Xeedless to say, much re mains to be done on these subjects. It is interesting to note that one of the most vexing problems to confront the research men Investigating the inhalation and retention of dust of various particle sizes is the flocculation of fine particles. Floc culated aggregates having an effective size many times that of the individual small particles behave like large particles as far as entrapment in the upper respiratory sys tem i i concerned. The same thing occurs m industrial dust exposures, not uniformly, but with considerable variation with type and source of dust. This is another factor hav ing an influence on the evaluation of dust exposure about which little is understood.