Document O1eB0nnZR1dZqQkDVdBwVQ5xw

Federal Register /. Vol. 51, No.. 119 / Friday, Jime 20; 1986 / Rules and Regulations 22657 Ag in A/C pipeproduction, OSHA with the slurry processing for drum PEL. This determination agrees with the recognizes that it is difficult to reduce brake linings, exposures lend to be hearing testimony by Dr. Franklin Mirer exposures during the cutting operation higher during the processing of the more of the United Auto Workers (UAW) who to below 2.0 f/cc. Technological friable dry-mix used'to make disc brake ascertained that current technology has improvements demonstrated in pads. Both dry-mix'and wet-mix the ability to lower exposure levels for construction activities, however, have processes are used ih the manufacture these practices to below 0.2-f/cc led to reduced exposures during cutting of clutch facing. These steps of fiber (Hearing Transcript of July 2,1984, p. to below the PEL of 0.2 f/cc. OSHA introduction and mixing closely 94J. believes that there is a strong likelihood resemble those of other primary that similar developments will occur in manufacturing processes (e.g., A/C Exposures for the employees involved in dry mechanical operations, however, 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 the floors clean--reduce greatly the amount of dust in the air created by the movement'of equipment. When used properly, this and other housekeeping chores can provide very effective dust control. (Exhibit 91-16. Section I. p. 9). 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. 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 the 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 PEL using engineering controls and work 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 the 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 [July 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. Textiles . 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 fanning, curing, and finishing. . - 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 practices. This feasibility determination is based on exposure data obtained during an RT1 site visit to the Raymark plant in Stratford. Connecticut [see Appendix B of R1A]. The Raymark plant-is a primary producer of friction materials and sheet gasketing and is the second largest producer of friction products of the 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 undesirable for Borne applications. 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 involved in the manufacturing of friction , run using dampened fibers, some fiberqualities 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 asbestoB 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 protection will be required. Friction products are molded using a wet-mix or a dry-mix process or a feasible for fiber introduction. Exposures for the 28 workers Involved in wet mechanical operations, in which operation, which is one of the problem areas for exposures, combs the fiber mix into a web of parallel fibers which is combination of the two methods. Dry the various products are prepared for then divided into strips known as mixing is generally used for disc brake curing/ranged from non-detectable to roving. The roving is spun and twisted pads and brake blocks, whereas wet 0.3 f/cc. with most appearing io be to produce single or plied asbestos mixing generally is used to mold drum below 0.2 f/cc. OSHA, therefore, yams. Due to the high velocity of the brake linings and clutch plates used in concludes that it is also feasible for spinning operation, this processing step automatic transmissions: Compared those activities to comply with a 0.2 f/cc has been a source of high exposures. GLEASON-000905