Document 4vmDz1w8ZLbj5jqZMMXMrB94R

Environmental laboratory of The City University of New Vort INSULATION HYGIENE PROGRESS REPORTS FROM THE HWSULATIOM INDUSTRY HYGIEIUE RESEARCH PROGRAM Irvin* J. IMkoA, M.U, Program Director Voi. 3, No. 4 Winter 1971 Dust produced by use of an unventi lated band saw. Without the back light ing used here, much of the dust would not be visible. Cutting pipe with band saw equipped with high-velocity, low-volume exhaust system. Compare absence of any air borne dust with that shown in uncon trolled cutting (picture left) -Shipyard Procedures Guide- Helps All Insulation Men The Winter 1970 issue of Insulation Hygiene Progress Re ports announced a joint effort by the Insolation Industry Hygiene Research Program, the U.S. Navy, the Department of Labor, and insulation manufacturers and contractors to control shipyard asbestos dust exposures. As part of that effort, Dancan A- Hotaday and William B. Reitze of the IIHRP prepared a procedures guide for shipyard insulation application and removaL Because of its-relevance to all insulation work, portions of it are given in this issue of Insulation Hygiene Progress Reports. A complete report was presented by the authors at the Inter national symposium on Safety and Health in Shipbuilding and Ship Repairing, at Helsinki, Finland, on Angnst 30, 1971. by Dancan A. Holeday " and William B. Reitze The general goal in all insulation work should be to maintain a clean environment Measurements of concentrations of asbestos fibers ("dust counts") in the atmosphere can be used to identify sources of contamination and to point out deficiencies in control methods. Primary reliance for control of ex posures, however, must be placed on faithful observance of operating rules. Control of Asbestos-Containing Dusts by Use of Substitute Materials Substitution of materials contain ing reduced proportions of asbestos or no asbestos at all, is becoming more common in ship construction. Before a material is substituted for asbestos, however, two questions must be carefully considered: a. Has the substitute material been tested? If not, it may turn out to be of the same or greater hazard than the material of known haz ard. This sort of thing has hap- Here Are Some of Many Ways to Reduce Dust pened in other environmental situations. Does the new material meet engi neering specifications and will it perform adequately under condi tions of use? Ms'ei ials containing reduced amounts of asbestos have been used in the fol lowing applications: a. Blanket and pad filling Substitution of the proper types of other pad fillers not only re duces asbestos dust during fabri cation and installation but also tends to lessen the problems dur ing subsequent "rip-out". Addi tionally, asbestos cloth which has been treated with a dust suppres sant is available and its use should also be encouraged. There are re ports that much less dust will be produced. b. Pipe covering and block Serious consideration should be given to those products contain ing lower amounts of asbestos fiber. Several British firms have introduced asbestos-free calcium silicate block and pipe covering. To date, however, this material has not been adequately evaluated in the United States to determine how it will perform in use. Reduction of Dust by Changes Work Methods a. Mixing Asbestos Mortar This operation has usually been done at the job site. While the time spent in mixing is quite short, considerable dust is pro duced. A tested method of control is to mix the mortar dockside under controlled conditions and package the mixed mortar in' sev eral containers for transportation to the job site. Mortar is also available packaged (Continued on second page) C/7 --I cn o X" cn cn o cn 'T 0cn0 co insulation Hygiene Progress Reports Vot. J, N*. 4 Winter 1971 Procedures Used at Puget Sound Naval Shipyard ST OOti 6607 from the Insulation Industry Hygiene Re search Program Editor: W. J. Nicholson, Ph.D., Published at the Environmental Sciences Laboratory (Irving J. Selikoff, M.D., Director 1, Mount Sinai School of Medicine of the City Uni versity of New York, New York, N'.Y. 10029 Advisory Council of 1IHKP Irving J. Selikoff, M.D. Program Director and Chairman E. Cuvier Hammond, Sc.D., Vice President, American Cancer Society, New York, N'.Y. Albert Hutchinson, General President, International Association of Heat and Frost Insulators and Asbestos Workers, Washington, D.C. Fred L. Pundsack, Ph.D. Vice Presi dent, Research and Development, Johns-Manville Corporation, New York. N.Y. PURPOSES OF THE INSULATION INDUSTRY HYGIENE RESEARCH PROGRAM (Continued from first page) in several sizes of plastic bags which have a spout through which water is introduced. Sufficient wa ter is added to moisten the mor tar; after premixing, the bag is opened ana the remaining water added. The carton in which the bag is packaged may serve as a mixing box and waste container b. Pre-cutting pipe covering and block in the fabrication shop Hand-cutting of pipe covering and block should be kept to an absolute minimum. Bend sections, pipe cover lengths, and blocks, should be cot in the fabrication shop on exhaust-ventilated equip ment How the Navy Does It At the Puget Sound Naval Ship yard, cut sections are dipped in water and then packed in plastic bags which are labeled to identify the location where they are to be used. The cut sections are still damp and relatively dust-free when they are applied and the plastic bags are available for use in collecting wastes. c. Pre-scoring blocks Insulation blocks should not be scored at the job site. Blocks which have been pre-scored by the manufacturer can be pur chased, or standard blocks can be scored in the fabrication shop by using an exhaust-ventilated gang saw. d. Insulating pipe assemblies in the shop Some pipe assemblies are quite intricate and are troublesome to lag while in place. A satisfactory method of doing these jobs, par ticularly during ship repair, which is employed by the Puget Sound Naval Shipyard, is to re move the assembly in conveniendy sized sections and transport them to the shop. Here the old insula tion is removed, any necessary repair of the pipes performed, and the assembled section relagged. Relag in the Shop Not only is dust dispersion re duced, but it is much more con venient to re-lag the section in the shop than when it is in place shipboard. Any insulation which is damaged during transport and fitting is repaired after the sec tions are in place. e. Hand-cutting at job sites Some hand-cutting at job sites is unavoidable. However, dispersion of dusts by these operations can be minimized. A portable downdraft table is used by the Puget Sound Naval Shipyard. This table has folding legs so that it can be carried down companionways and set up conveniently to the work. A small industrial vacuum cleaner is the source of exhaust. Scrap is dropped into a plastic bag and a (Continued on third page) 1. To develop improved methods for minimizing ex posure of insulation workers to dusts and fumes encoun tered in their work. 2. To disseminate knowl edge of these improved methods of dust control wherever they may be ap plied advantageously and to offer cooperation, advice and assistance toward their universal adoption. . High temperature mortar packed in plastic bag. Water is added to bag through spout and mortar moistened before opening. The moistened mortar is removed as required and mixing completed in shipping container. All wastes are placed in container and sent to disposal at end of shift .- . "S. ! 't. .r. s.': l `i 1 -- "3 I - --------- Procedure used at Puget Sound Naval Shipyard for handling bend sections. Sections are cut in fabrication shop, dipped in water and placed in plastic bag. The bag is then labelled with the job-site description. 398472 Dampening fibrous glass blanket filler before cutting. Note lateral draft hood in which fabrication is done. (Continued from second page) dropcloth is placed on the deck under the equipment. /. Fabrication of Pads and Blan kets Pads for valves and machinery should be fabricated in the shop whenever possible. Amosite has been largely replaced by fibrous glass filling with covers of an asbestos cloth which has been treated with dust suppressants. As an effective means for suppressing dust dispersion and collection, the fibrous glass blanket is unrolled, dampened and rerolled. This pro cedure insures that all the blanket will be dampened. The blanket and asbestos cloth shapes are cut in the lateral draft booth. g. Housekeeping and Clean-up Essential parts of a dust control program are housekeeping and clean-up procedures. Meticulous attention must be given to re stricting the spread of dust and larger wastes. Use of a dropcloth under a work area vividly illus trates how much waste would be distributed over the general area or to lower decks if one were not used. Areas should be cleaned up at the lunch break and the end of each shift, using an industrial vacuum cleaner to collect dust and small scrap. In all possible instances, work men should clean up their own areas. Where work rules prohibit this, the clean-up crew should be under the direction and super vision of the insulation foreman to insure that proper attention is given to this important subject. Retetm if Dasts by Use if Lmi Extant VMtibtiti saws for catting asbestos cement board are well controlled with these systems. a. Ventilation of Large Power Tools---Band Sates Extensive use of band saws both in dockside fabrication, shops and, on board larger ships such as aircraft carriers make emissions from band saws a major source of asbestos dust. Control devices for such saws have been known for yean and are relatively sim ple. Conventional low-velocity, high-volume systems, using a negative pressure baghouse for air cleaning, are practical in a fixed installation fabrication shop. Because some degree of porta bility is desirable in a temporary shipboard fabrication area, a high-velocity, low-volume dust collection unit is desirable for Cutrol if tinier of Wortaea fttpced a. Scheduling of Insulation Work Standard industrial hygiene prac tices call for insoladng operations which contaminate the atmosphere with toxic materials. Areas where insulation work is being done under conditions in which dust might be created should be iso lated by non-flammable curtains or other means. Whenever possible, work should be scheduled to minimize the numbers of other tradesmen in the area. Ship con struction operations are more readily scheduled than are ship repair or ship-breaking jobs. However, every effort should be made to keep the number of men exposed at a minimum. In par ticular, rip-out of old insulation should always be isolated and, if necessary, performed on an offshift Trained workmen supplied with proper protective equipment should always be used for rip-out work and it should be scheduled for rapid completion. Personal Protective Equipment In addition to dust suppression and dust control procedures, personal pro tective equipment is often necessary to reduce exposure and limit the spread of contamination. The equip ment described below is used in con trol programs. Portable down-draft table developed by Puget Sound Naval Shipyard for use shipboard. Lightweight industrial vac uum cleaner is used as the air mover. Note plastic bag for scrap and drop cloth on deck. such use; it may also be suitable for fixed installations. The air mover is an industrial vacuum cleaner which pulls about 50 cubic feet of air per minute past the saw blade at velocity of more rhn 10,000 feet per minute. This system is a very efficient dust col lector. Units such as this can also be designed to control dusts pro duced by table saws and gang saws. a. Protective Clothing Protective clothing is required to keep contamination confined to the work areas. One method is to issue disposable coveralls which can be removed when leaving the (Continued on fourth page) b. Ventilation of Hand Power Tools High-velocity, low-volume collec tion systems control dust emis sions from most small power tools adequately. Saber saws for cut- ring pipe covering and rotary lisa at dropcloth to contain wastes and facilitate clean-up. 398473 STOO'46608 A small industrial vacuum cleaner being used by a Local 62 asbestos worker for dean-up. (Continued from third page) work area or some time prior to entering the locker room and placed in plastic bags for disposal. Resin Impregnated Paper A satisfactory type of protective clothing consists of resin impreg nated paper coveralls. These are inexpensive and readily disposa ble. They prevent spreading con tamination to laundries and elimi nate pilferage. They are worn for one shift, then removed and placed in plastic bags for disposal with other asbestos-containing wastes. b. Respiratory Protective Equip ment Occasionally some operations gen erate so much dust that it is virtually impossible to maintain satisfactory atmospheric concen trations of asbestos fibers and respiratory protection must be provided to the workers. A variety of respiratory protective equip ment is available from which devices suitable for various situa tions can be selected. American National Standard Z88.3-1971, Safety Guide for Respiratory Pro tection Against Asbestos-Contain ing Dusts (obtainable from Amer ican National Standards Institute. 1430 Broadway, New York, N.Y. 10018) should be referred to for detailed information. Invisible Dust It is emphasized that unsatisfac tory amounts of respirable dust can be present in the air even though conditions are not visibly dusty. 1. Air-supplied Respirators Extremely dusty jobs, such as ripout of old insulation where dust concentrations are very high, re quire use of air-supplied respi- rators which will deliver clean, dust-free air to a facepiece or hood. Two general types are available: air-line and self- Saber saw equipped with high-velocity, low-volume exhaust system. powered. a) Air-line respirators in which air is supplied to a hood, helmet or facepiece give the greatest de gree of protection. Air is fed to the facepiece from a compressed air-line. The air source must be located in an uncontaminated area and if the source is not specifically designed for breathing purposes, a temperature sensing alarm must be installed on the compressor or a carbon mon oxide monitoring device must be installed in the air-line. Disposable Hood Anti-freeze compounds should not be used in the compressor system; water vapor must be removed by dessicant and oil mists removed by a filter. A plastic, disposable hood has been developed by the Puget Sound Naval Shipyard for situ ations where a very high degree of protection is required. This hood and other similar ones are available commercially. The air line should be fastened to the hood with a quick-disconnect fitting. Self-powered Respirators b) Air-line respirators connected to a compressed air supply limit movement, and this limitation can be troublesome. Self-powered res pirators do not impose such limi tations, but they do add to the equipment the workman must carry and they also require care ful maintenance. 2. Particulate-filtering Respira tors There are several types of par ticulate-filtering respirators. Those with a half-mask facepiece are considered most suitable for use by insulators. Only those ap proved for protection against as bestos dust by the U. S. Bureau of Mines should be used. These devices are recommended for use in situations where the atmos pheric concentration of asbestos fibers is at relatively low levels. All the recommendations for res pirator-fitting, training of work men and maintenance, detailed in Z88-3-1971 should be followed. a) Reusable particulate-filter ing respirators A variety of reusable particulatefiltering respirators are available. To insure proper fitting, several different makes should be avail able from which the workman can select one. No one model respira tor facepiece will fit all faces. Routine maintenance is absolutely necessary to replace clogged filters and leaking inhalation or exhala tion valves. Unmaintained res pirators produce a false sense of security. Maintenance Troublesome b) Disposable particulate-filter ing respirators Operation of an adequate respira-OO tor maintenance program can be--{ troublesome and, if only a feW(--> men are involved, impractical.^--, Disposable respirators are avail-__ able which are designed to be"*" worn for no longer than one shift^"' and then discarded. CH CD Education and Training No dust control program can be effec tive unless workmen and supervisors understand the hazards associated with the jobs, the sources of the hazards and the reasons for following recommended procedures carefully. Understanding is only obtained by education of personnel and training in correct operating procedures. For an education and training program to be successful, both management and labor must be concerned and partici pate. As with all safety programs, it is essential that first-line supervisors be interested in and cooperate in the work. The harmful effects of neglect of pro cedures for controlling asbestos dust are not apparent for many years. Therefore, it is more difficult to con vince workmen and supervisors of the necessity of following rules for working with insulating materials than if more obvious physical haz ards were involved. Education in hazards associated with use of insulating materials and in struction in correct work practices should be included in apprentice training programs. PHOTO CREDITS: Pg. 1, I.I.H.R.P.; pg. 2, Ryder Industries and Puget Sound Naval Shipyards (P.S.N.S.); p. 3, P.S.N.S.: rnr. 4. I.LHJUP. and PJSJiJS 398474