Document 0g9R2ZM0Maj5mLGQoZOLyGDkx

FILE NAME: National Safety Council (NSC) DATE: 1953 Nov DOC#: NSC028 DOCUMENT DESCRIPTION: NSC - National Safety News - Protection Against Contaminated Atmospheres PTA IW TIFFS" | EXHIBIT N S l2 4 i Enclosed bias-!- rooms with down-dra-fl exhaust ventilation and the ur.o of suppiied-alr respirators h av e mini mized hazards of abrasive blasting. I i Protection Against Contaminated A tm ospheres By BENJAMIN F. POSTMAN PRO TECTIO N against contaminated atmospheres represents a narrow but vitally important band of personal protection. This discussion will include protective devices available for normal indus trial operations, but not equipment for mine rescue or fire-fighting purposes. Air Supplied HelmetB Until the appearance of the airsupplied helmet, one of the most serious exposures was in the cast ing cleaning or blasting room where sand-mold castings were cleaned of adhering molding sand. For years this was the lowest paid and dirtiest job in the foundry. Six months exposure in a blasting room where silica sand was the Bf.n.iamin F. P ostman is Industrial Hygiene Engineer, Accident Prevention Department, Employers Mutual Liabil ity Insurance Company, New York City, This article has been adapted from a paper presented at the 23rd Annual Convention, Greater New York Safety Conneil. only type of abrasive used--utiliz ing either a rag or handkerchief about the nose and mouth for pro tection--was all that was necessary to. produce a case 'of disabling or third stage silicosis within 15 or 20 years. It is, therefore, with a feeling of reverence that we inspect a mod ern air-supplied helmet, because, if properly used, operators in casting cleaning rooms will not be ex posed to any dangerous concentra tion of silicious dust. The use of steel grit or shot has further re duced the potentiality of silicosis. To be sure, the use of a supplied air helmet protects the operator irrespective of the type of abrasive used. At present there are fifteen tyres of helmets, produced by eight dif ferent organizations, which have been approved by the U. S. Bureau of Mines. Incidentally, it is to be emphasized that the types of res piratory protective equipment menlioned refer only to equipment ap proved by the U. 5. Bureau of Mines. Those who purchase, or supervise the use of respiratory protective equipment should insist on "approved equipment." Blasting helmets are costly. Op erators should be instructed not only how to use them, but how to store them when not in use. The greatest abuse'seen in the field is- Supplied-air respirator and rope kept on side of degreasing tank. Air flow to this type of respirator should not as- coed 20 feet per minute. :>. i ' V ira j i l . F :S Nafiona/ Safely News, November, ?53 s- thrown into a corner of ilafting room or on some jrir|..edged castings. Some helare provided with suspension nn,r^ at the top of the head secnan. so that it may be suspended r M, a book when not in use. \[ air supplied to helmets _j,,,n d pass through a ' filter unit ,,, rr. uove oil fumes, moisture and nuisance or toxic eonstit-ucommon to compressed air ,,ns Some years ago, an operator ,, a hasting room was found dead, presumably from carbon monoxide which was generated when oil luhrici ted valves on a compressor [icca lie inoperative. This was the duly answer advanced for this deal i. A fatality of this type is rxtr; mely rare. A: a result, some blasting hel mets are provided with air from sepamte pressure blowers, utilizing shop or outdoor air. One such unit, called a clean air blower, not .inly compresses the air for the helmet but cools the air to remove llm heat of compression, and then was!os and humidifies this air. Where helmets or other types of air-supplied units receive air which is too cool, creating a chilling ellec: on the head, neck or face of the operator, an air-line electric heater may be provided to heat this sir before it enters the helmet or it ask. Data relative to the normal air supply for each type of helmet should be obtained from the manu facturer. The wearer of the helmet should be instructed to regulate the air supply valve so that at all times he will receive an adequate supply of air for breathing. Air ranging from 3 to 8 pounds per square inch in pressure wall provide from 6 to 20 cubic feet of air per minute to the helmet. Dust Respirators It is difficult to force personnel to wear any type of respiratory protection. Personalized indoctri nation relative to the reason and necessity for wearing respiratory protection is sometimes a normal and/or a basic necessity. Use of respiratory protection for more than one-half hour at a time is not desirable. However, during a recent survey of a casting cleaning room, all operators usmg portable grinding units wore safety goggles and approved dust respirators all day long. Local exhaust, either downdraft through floor grilles or on benches along the wall for the various sizes of castings, would considerably reduce exposure to excessive dust concentrations resulting from the use of portable grinding units. In another casting cleaning room, all of the operators wearing approved ino best equipment may bo useless in an emergoncy if employees ore not ivnlruc+ed in its use. These employees of a public utility company are receiv ing instructions In respiratory protection, dust respirators looked like dogs frothing at the mouth, due to the saliva dripping from the exhaust valve of the respirator. Though portable grinding is considered a heavy-duty operation, an analysis of excessive labor turn over may determine the cause due to unfavorable operating condi tions ancTnol due-to a lack of pay. It should be remembered that the dust p ro d u ced from the abraded wheel, which may be alu minum oxide or carborundum, with castings of grey iron or steel, are so-called nuisance dusts which do not produce silicosis or tuber culosis. When bronze or brass castings are processed, there is a potential lead exposure. However, the continual heavy dust concen trations produced by uncontrolled portable grinding units may ag gravate a sinus, bronchitis, or asthmatic condition, which may become compensable. The liberal ity of some awards, based on ag- --To l.r>4 National Safety News, November, 1953 25 that he had extremely high blood pressure with dizziness, headaches and other symptoms referable to hypertension. Following prephcement exami nation, the personnel manager of the hotel was advised that this man was not physically qualified for employment as a window cleaner. Good general evidence of the value of industrii I medical care may be found in a study involving some 3,500 plant:, made by the National Associatisn of Manufac turers in 1951. The surveyed com panies, representir g every section of the United 5tat:s, constituted a wide range of sizes and types. They reported the following average sav ings from medical care programs, which, at first ma) seem too good to be true: A 44 per cent dro: in accident fre quency: A 4-6 per cent drep in occupational diseases; A 29 per cent d n p in labor turn over; A 39 per cent dro: in absenteeism; A 30 per cent drop in compensation insurance premiums. The keystone of any worthwhile program is a provision for replace ment and periodic physical exami nations. Reasons: 1. Such a set-up minimizes the hiring of persons for jobs they are not physi cally equipped to fill. 2. It enables on employer to place handicapped persons where they are most suited. The first point is obviously a big factor in avoiding accidents. The second is of special importance these days, when a tight labor market makes industry rely more and more on elderly and physically handicapped persons. Respiratory Protection -- From page 25 gravation factors, is becoming a serious problem. Workers should not be required to wear respirators for long peri ods. If this type of protection is necessary, then an analysis should be made of the operator technique and/or the job requirements. In variably a change in one or both is found necessary. A preventive cleaning, steriliza tion and maintenance program should be developed for all respi rators used in a plant. This should not be left to the individual worker. A program of this sort is feasible in a moderate sized and large plant, but it has its inherent difficulties in the smaller plant. For this set-up, one intelligent op erator may' be assigned to this work, possibly with some extra compensation as an incentive. Chemical Cartridge Respirators In all cases, facelet cloths should be provided for all types of respi rators as a means of reducing face rash in not weather. Creams ap plied to cheek areas are also' de sirable, and should be provided for all personnel who use respira tors. An ever increasing field for the ' These Simple Units A d d Up to INCREASED PROPERTY PROTECTION and ! LOWER INSURANCE RATES! ' SYSTEM use of cl: tors is in Depen din nique an; sp ra y e d ,: nets or which do work cloe the unit, I for a resp the entire Some c rators ar buffer co' replaceabi catch the ; pigments Lacquers h sprayed i r . contain it w ous claim: Suit". reported &!.. cians, whe gT trial open of a pah spraying The fu: cartridge percentage solvent v; oversprav safl exposed. I: sibility of the cartrii smell solvi tor. For I sense of serious cn Inhalatl without th cartridge " headaches instances. These are should be Quickly Pays for Itself! The CHICAGO W ATCHCLOCK System' is so reliable, u ;ers are given lower insurance rates. The CHICAGO System enables reliable watchmen to PROVE they're on the job. It keeps a permanent record of their perform ance .. . YOU get extra protection against EIRE, TH EFT and SABOT AGE. Send for FR EE hoc Met that explains (fit operation of the CHICAGO WATCHCLOCK System and how this low-priced a installation is made quickly with only a screw va driver! mm X W rite to w CHICAGO WATCHCLOCK Division Great Lakes industries, Inc 1524 5. WABASH AVE., CHICAGO 5, ILL Offices in Principal Cities Canister Masks Though P'rators ar pheres whi dangerous not more per cent or or 1,000 j million pa; rare that d of vapor cc mg enviro: bpe of r Practical e 0T extensiv' technical re pirator ma: 15 Wafiono? Safety New s, N ovem ber, 19$$