Document 06NqVGbKVVy7Z9e9dJwX5eqQb

Federal Register / Vol. 51, No. 119 / Friday, June 20, 1986 / Rules and Regulations 22663 Based on the EEH study, OSHA has and installation of vinyl/asbestos determined that these exposures can be -flooring. controlled to levels under O.l.f/cc Asphalt Roofing Felts and Coatings. through the use of shrouded or doty Asbestos roofing felts are composed of tools. Thus, the Agency has determined approximately 85 percent chrysolite that it is feasible to comply with the 0.2 asbestos, saturated with tar or asphalt. f/cc PEL during the installation of A/C During installation, the roofing felts are pipe. cut to length with knives and are A/C Sheet. In new construction attached to the roof with nails. Asphalt activities, the installation of A/C sheet is then applied-over the felts. The may require sawing, drilling, or sanding removal of roofing felts generally operations. Much of this activity, requires chopping (with an axe) or however, is performed by primary and sawing (with a circular mounting on secondary manufacturers, thereby wheels) the existing roof membrane into reducing the need for additional pieces that can be pried or scraped from fabrication in the held. the the deck. Because the asbestos For on-site fabrication that does fibers are encapsulated with tar or occur, the use of tools fitted with local asphalt during the production of the felt, exhaust shrouds connected to a HEPA the fiber release during installation and vacuum have been demonstrated to removal is expected to be relatively low. reduce concentations significantly In written testimony, Eric Wormser of (Exhibits 312-A and 298J. TWA Gibson-Homans emphasized that during exposures during the installation of A/C the "tear-off' of an old roof, "there still sheet have been reported to be below is no asbestos exposure since asbestos 0.2 f/cc, even for drilling and cutting fibers in any old coating or cement are (Exhibit 84-474, Appendix A]. In fact, encapsulated in the product" (Exhibit some studies reported only from 40 91-16, Section K, p. 8], Nevertheless, as percent to 50 percent of the the condition of the roof deteriorates measurements above concentrations of due to age and exposure to the elements, 0.1 f/cc (Exhibits 308 and. 333, Section the quantity of asbestos fibers released R], Thus, OSHA has determined that it will increase. This is clearly shown in is feasible to meet a PEL of 0.2 f/cc studies conducted by Johns-Manville, through the use of engineering controls and reported by GCA Corporation during the installation of A/C sheet, (Exhibit f>4-474, p. 3.17], Personal Vinyl/Asbestos Floor Tile. In four breathing zone and area.samples were studies [Exhibit 84-474, p. 314] collected at 11 separate construction performed for the Resilient Floor sites to evaluate worker exposure to Covering Institute, personal breathing asbestos during the removal and zone samples were collected to evaluate subsequent replacement of old roofing. worker exposures during various The results indicated TWA airborne installation and removal operations for fiber concentrations as high as 0.80 f/cc both sheet vinyl floor covering and during the installation of roofing felts, vinyl-asbestos floor tile. The results with a mean concentration of 0.22 f/cc. indicated that TWA airborne fiber ' Thus, engineering controls and work concentrations ranged from below ' practices may not reduce exposures detectable (less than 0.01 f/cc) to 0.10 f/ below the 0.2 f/cc PEL in all cases and cc during the installation'of sheet vinyl, respirators will be required during some and from below detectable to 0.03 f/cc roofing projects. during the installation of vinyl-asbestos Asbestos Abatement. Because of the floor tile. In another study, Dunnigan concerns about potential health hazards, and Lebel (Exhibit 84-474, p. 3.14] many building owners and managers, as reported TWA- coricentrations below well as industrial firms, are performing detectable levels for the installation of asbestos-abatement projects to prevent vinyl-asbestos floor tile. or reduce the potential for fiber release. When Installing a new floor, it is often Generally; these involve either removal necessary to first remove the old tile or (with or without replacement using a . sheet vinyl Door covering. The data non-asbestos substitute), encapsulation obtained [Exhibit 84-474, p. 314] indicate with a polymeric coating, or enclosure. that when the recommendations of the In recent years, many contracting firms Resilient Floor Covering.lnstitute (e.g., have been formed that specialize in wet sweeping and handling, and asbestos abatement. prohibiting powersanding and blowing In general, asbestos removal involves asbestos dust) were followed, average one of two categories of products; (1) TWA alrbome'fiber concentrations Spray-on or trowel-applied fireproofing were below the 0.2 f/cc PEL duringthe or acoustical plasters; and (2) insulation removal of the old-floor. Thus, OSHA of pipes, boilers, or process equipment. determined that it is feasible to comply In removing asbestos, a widely used with the 0.2. f/cc PEL during the removal practice is to wet the material to be removed, usually with water having a surfactant added to enhance penetration [Exhibit 84-474, p. 3.22). The use of vacuums equipped with HEPA filters, or wet mopping are the preferred methods of clean up. In written testimony, Suzanne Kossan of the International Brotherhood of Teamsters gave evidence to support the effectiveness of wet methods, when she stated the following; Of over 7.000 air samples gathered [in 19B3j at Maryland construction Bites, approximately one-half of the samples showed asbestos exposure levels less than 0.1 f/cc, 8-hour TWA. (Exhibit 223, p. 3j. The data by T. Joel Loving of the University of Virginia [Exhibit 84-474, p. 3.23] show that although wet methods are effective in reducing exposures to below the current PEL of 2.0 f/cc during asbestos removal, 47 percent of the observations exceeded 0.5 f/cc, and a total of 59 percent exceeded the 0.2 f/cc PEL. The Loving report also summarized similar data from other investigators. Tho data from Clayton Environmental Consultants, Inc. [Exhibit 84-474. p. 3.27] for the removal of fireproofing and acoustical plastics using bothwet methods and a HEPA vacuum, for ' example, show eight short-term exposures ranging from below . detectable to 170 f/cc. In fact, of 255 personal samples collected, 79 percent exceeded the 0.2 f/cc PEL. Joseph Durst, ]r,, of United Brotherhood of Carpenters and Joiners of America,- acknowledged the difficulty of reducing exposure levels during abatement projects and stated as follows: Although exposures could be brought down to the level of 500,000 to one million fibers/m' [through the use of wet methods and engineering controls), exposures below 100,000 fibers/m* may be difficult to achieve in some cases. In those cases personal protective equipment will be necessary and would be the only feasible way to reduce exposures to below safe levels. (Exhibit 143, p. 4.) Thus, on the basis of these data, OSHA has determined that engineering controls cannot routinely reduce exposures below the 0.2 f/cc PEL during major asbestos removal projects and that the supplemental use of respirators may be required. For minor removal projects, where small amounts of asbestos are removed. OSHA has determined that the 0.2 f/cc PEL Is feasible. For example, data supplied by Clayton Environmental Consultants, Inc., indicate that 8-hour TWA exposures during the removal of preformed pipe insulation from process pipe at petroleum refineries using wet methods, range from less than 6.01 f/cc GLEASON-000911