Document QkD5RZnpbYL3oDRwaZ49N55r6

Federal Register / Vol. 51, No.. 119 / Friday, June 20; 1986 / Rules and Regulations 22657 As in A/C pipe,production, OSHA recognizes that it is difficult to reduce exposures during the cutting operation to below 2.0 f/cc. Technological improvements demonstrated in construction activities, however, have led to reduced exposures during cutting to below the PEL of 0.2 f/cc. OSHA believes that there is a strong likelihood that similar developments will occur in the manufacture of A/C pipe and sheet and in the production of other primary asbestos products. Other innovations, such as shrouded tools used in.field . cutting, might be applied on a larger scale to current cutting practices in factories. As suggested by Dr. Bragg, the local exhaust ventilation and good housekeeping used in the processing steps of A/C pipe could be successfully applied to A/C sheet processing. Mr. Alfred Netter of Supradur Manufacturing Corporation recognized in his written testimony the importance of good housekeeping when he stated the following: Work practices--merely keeping Ihe floors clean--reduce greatly the amount of dust in the air created by the movement'of equipment. When used property, this and other housekeeping chores can provide very effective dust control. (Exhibit 91-16. Section I. p. 9J. OSHA, therefore, concludes that with a combination of engineering controls and work practices it will be feasible for this sector to comply with the 0.2 f/cc PEL for all operations except sanding, where supplemental respiratory protection will be used to achieve the PEL. . Friction Products Asbestos friction products include drum brake linings, disc brake pads, and clutch facings for automobiles, as well as materials for industrial and commercial applications where motion must be controlled. Although each of these products is manfactured by a unique process, the basic order is fiber introduction, wet or dry mixing of the asbestos with other ingredients, and production forming, curing, and finishing. : . .T OSHA has determined that it is feasible to achieve exposure levels below 0.2 f/cc during all operations except grinding, by using engineering controls and work practices. For grinding, supplemental respiratory protection will be required. Friction products are molded using a wet-mix or a dry-mix process or a combination of the two methods. Dry mixing is generally used for disc brake pads and brake blocks, whereas wet mixing generally is used to mold drum brake linings and clutch plates used in automatic transmissions; Compared with the slurry processing for drum PEL This determination agrees with the brake linings, exposures tend to be hearing testimony by Dr. Franklin Mirer higher during the processing of the more of the United Auto Workers (UAW) who friable dry-mix used to make disc brake ascertained that current technology has pads. Both dry-mix and wet-mix the ability to lower exposure levels for processes are used in the manufacture these practices to below 0.2-f/cc of clutch facing. These steps of fiber [Hearing Transcript of July 2,.1984, p. introduction and mixing closely 94). resemble those of other primary manufacturing processes (e.g., A/C pipe). Following mixing, the dry mix is fed through a compression molder and the wet mix through an extruder. Then, formed strips are cut and bent into various widths and lengths. Dry-mixed formulations are transferred to pressing molds where slabs are formed, . sometimes after a pre-heating step. The slabs are hot pressed, are sawed into specific parts, and are then sent to a curing oven. Following curing, the parts undergo finishing steps to produce.the final product. These steps include sawing, grinding, drilling, tapping, and boring. In the friction products industry, finishing operations generate Ihe greatest quantity of emissions, with as much as.30 percent of the asbestos in the products being ground away as dust. The Friction Materials Standards Institute claimed that a 0.2 f/cc TWA PEL is not feasible [Exhibit 90-180]. OSHA has determined, however,-that although there are some operations for which the 0.2 f/cc PEL is not yet feasible, it is feasible for most operations to comply with the 0.2 f/cc Exposures for the employees involved in dry mechanical operations, however, ranged from 0.07 f/cc to 1.7 f/cc. About one-third of the workers were regularly exposed to levels above 0.2 f/cc during the grinding of drum brake linings and the pressing and machining of clutch facings. The difficulty of controlling exposures for these dry mechanical operations is consistent with data presented by Dr. Bragg which show that exposures at many of the dry mechanical operations average between 0.3 f/cc and 0.7 f/cc. Dr. Bragg referred to Ihe impracticality of using wet methods during these particular practices because of their detrimental effect on the final friction product [Exhibit 235-A, p. 79). Dr. Mirer of UAW acknowledged the high exposures during the manufacture of friction products and suggested the use'of substitute materials IJuly 2,1984, Transcript, p. 92], The AFLCIO also has stated that the production of asbestos friction product's is a problem area in terms of exposures [Exhibit 335, p. 44], Thus, it appears that supplemental respiratory protection will be required to comply with the 0.2 f/cc PEL during grinding operations. PEL using engineering controls and work Textiles practices. This feasibility determination is based on exposure data obtained during an RTI.site visit to the Raymark plant in Stratford, Connecticut [see Appendix B of RIA]. The Raymark plant-is a primary producer of friction materials and sheet gasketing and is the second largest Asbestos textiles are manufactured by either wet or dry processing. Not all asbestos textile products can be made by the wet process because chemicals used in the wet process alter the characteristics of the fiber making it undesirableforsome applications. producer of friction products of the Likewise, although some operations of plants in the RTI survey. The exposure the conventional "dry" method could be data reveal that most of the workers run using dampened fibers, some fiber involved in the manufacturing of friction . qualities required by the final textile products are.exposed to less than 0.2 f/ product exclude the use of dampening cc of asbestos. Exposures for the 15 techniques. employees involved with fiber In the dry process, the asbestos fiber introduction for asbestos friction is debagged and dry blended. Cotton, materials ranged from 0.03 f/cc to 0.21 f/ rayon, or other natural or synthetic cc, which is similar to the exposure data fibers can be added to impart strength in A/C pipe manufacture. OSHA, and other characteristics. Following the therefore, believes that 0.2 f/cc PEL is standard textile processes, the carding feasible for fiber introduction. operation, which is one of the problem Exposures for the 28 workers involved areas for exposures, combs the fiber mix in wet mechanical operations, in which into a web of parallel fibers which is the various products are prepared for then divided into strips known as curing, ranged from non-detectable to roving. The roving is spun and twisted 0.3 f/cc, with most appearing to be to produce single or plied asbestos below 0.2.f/cc. OSHA, therefore, yams. Due to the high velocity of the concludes that it is also feasible for spinning operation, this processing step those activities to comply with a 0.2 f/cc has been a source of high exposures. GLEASON-000905