Document K6RBNvK2zrRBaxEnz8eYoGgrK

22660 . Federal,.Register / Vol. 51, No. 119 / Friday, June 20,1986 / Rules and Regulations consistent with the limiled-1983 333), primary manufacturers process environment Exposures occur in this : exposure data submitted by Dr. Bragg as only 30 percent of the preform that they sector when stable asbestos products well as with the position of the AFL- produce. The remaining 70 percent Is are altered by dry mechanical CIO [Exhibit 335, p. 41). shipped to secondary manufacturers operations that release encapsulated Asbestos-Reinforced Plastics ' who shape and finish the asbestosbased plastic resin. In the shaping fibers into the air. As supported by data, exposures resulting from these dry Due to their heat-resistant qualities, process of the final plastic product, the mechanical finishing operations can be asbestos-reinforced plastics are used in preform is rolled, stamped, pressed, or controlled by shrouded tools and by wet the electrical, electronic, automotive, molded. The product is then cured In an methods in some cases. As with primary and printing industries. In the isolated area with a ventilation system. manufacturing, OSHA has determined manufacture of these plastics, raw The strength and stiffness, that, it is feasible for these industries to asbestos.fiber is introduced and dry characteristics of the final product are comply with the 0.2 f/cc PEL In all mixed with catalysts and other partially controlled by the time and operations with the exception of some additives. The mixture is heated.into a temperature conditions during curing. maintenance activities (e.g., repairing or resin in the form of pellet or powder OSHA's feasibility determination for servicing the controls that protect the preform. The preform may be further asbestos reinforced plastics is baBed in other workers) and a limited number of processed onsite or packaged and sold part upon data obtained-from two plants dry mechanical operations. The basis for to other manufacturers. Based on the surveyed by RT1 and from three OSHA this determination is presented below. information provided in a 1984 report prepared by Versar for EPA [Exhibit MIS reports. These data are summarized A/C Sheet in Table 17. The secondary manufacturing of A/C Table 17.--Worker Exposures During the Manufacture of'Asbestos-Reinforced Plastics sheet prepares die product for specific installation requirements. This fabrication requires the same dry Job dassiticalion/process Mean ft-hr TWA exposure (/ec> Standard donation No. of observa tions Source of data mechanical processes that were described for primary manufacturing processes, such as sawing, drilling, routing, beveling, and sanding. Some of RTI survey.* the firms that responded to RTI's survey 0.14-0.57 0.04 N/A 0.047 RTI survey.* 95 RTI survey.4 13 OSHA MIS. reported using wet spray, during sawing and routing. As in other processes, tools are equipped with local exhaust Number ol employees who were represented by average exposure was used tinea data on the number of samples were not given. * Identified as plant "1." Identified as plant "a** * Identified as piant-*>n.N N/A=Not available. ' N/DaNot detectable. Source; US. Department of Labor. OSHA, Office of Regulatory Analysis. systems. High exposures are likely to remain a problem during sanding, which: is unique to A/C sheet production. OSHA's determination of feasibility in this sector is based on data obtained in response to the RTI survey (see Table . Since these data, especially the MIS. . data, do not represent plantB using the best controls. OSHA's determination is also based upon the technologies currently available in the other primary sectors.' The data indicate that exposures at the fiber introduction and wet . mechanical processes in this industry . (e.g.. asbestos textiles made into fire-' resistant clothing). Receiving and handling these primary products do not pose exposure problems. Compared with the primary processing steps of fiber introduction, mixing, and conveying loose fibers, secondary fabrication takes place in a more controllable 18), As all of the exposures shown in the table are below 0.15 f/cc, and because ' the 1983 data [Exhibit 235-A, Table XXII] for a secondary user of A/C sheet are also all below 0.15 f/cc,- OSHA has determined that it is feasible.for this sector to comply with the 0.2 f/cc PEL, except for sanding, where respirators will be required. are below 0.2 f/cc and that the problem exposure' areas during the manufacture of. the plastics appear to be in dry ' Table 18.--Worker Exposures During Secondary Manufacture of Asbestos Cement Sheet finishing operations. These operations are similar, to dry mechanical operations in other asbestos products manufacturing industries and include Plant designation Annual production Job classification' ftJvTWA axpostee levels (t/ cc) . . NOl of workers St 3: grinding and sanding, which OSHA has determined may not be feasible to > 1 mISon tbs.____-- 7.000 sq yds_________________________ achieve exposure levels below 0,2 f/cc without the use of respirators. Thus, OSHA believes it is technologically feasible for most operations to achieve a 0.2 f/cc TWA, but that respirators will 21,000 sq yds - ____ i----------- Other--------- -- --................. -..... ....... <0:10 15 N/Do Non-detectaWs. N/AoNot avarf&Die. Source;' U.S. Department of' Labor, OSHA. Office of Regulatory Analysis, based on RTI survey tAppendix C of the RlAJ. . be required during grinding and sanding. Secondary Manufacturing Secondary manufacturers modify or fabricate primary asbestos products to . yield final products (e.g., impregnated roofing felt) or intermediate products - Friction Products ' In this sector, manufacturers assemble automatic transmission parts, disk and drum brakes, and automotive.clutches. Asbestos products undergo a final forming process which may include grinding. The product is then assembled by means of a riveting operation. An example of this secondary fabrication of friction products is the assembly of disc brakes. The asbestos brake pad GLEASON-000908