Document 2jLV8ROwDOk7j6Zb0YG5kx9oL

FIBER STANDARD - General Information page 1 5-fiber/cc Rule & Regulation, OSHA, U. S. Dept, of Labor Fed. Reg. Vol. 37, No. 110, 6/7/72 Excerpt; (page 11318, part 1910, no. 1) Acceptable concentrations of asbestos dust. The proposed standard would limit occupational exposure to 8-hour time-weighted average (TWA) airborne concen trations of asbestos dust not exceeding five fibers longer than five micrometers per milliliter. Concentrations above five fibers but not to exceed 10 fibers (ceiling concentration) would be permitted up to 15 minutes in an hour, but for not more than 5 hours in any one 8-hour day. 2-fiber/cc NIOSH in effect has recommended that the five-fiber TWA and 10-fiber peak concentrations be permitted only for 2 years; thereafter, TWA concentrations should be not more than 2 fibers per cubic centimeter (cm.3) of air, and peak concentrations should not exceed 10 fibers/cm.3, with no time restriction. Numerous objections and counterproposals have been made, with regard to both the limits of asbestos fiber concen trations and the time periods to comply with them. Excerpt: (Page 11320, part 1910,93a, No. 2) Permissible exposure to airborne concentrations of asbestos fibers--(1) standard Effective July 7, 1972. The 8-hour timeweighted average airborne concentrations of asbestos fibers to which any employee may be exposed shall not exceed five fibers, longer than 5 micrometers, per cubic centimeter of air, as de termined by the method prescribed in paragraph 'e.' (2) Standard Effective July 1, 1976. The 8-hour time-weighted average airborne concentrations of asbestos fibers to which any employee may be exposed shall not exceed two fibers.longer than 5 micrometers, per cubic centimeter of air. (3) Ceiling Concentration - see above. 0.5-fiber/cc 0.5-fiber/cc 0.1-fiber/cc Prepared 1/27/77 Proposed Rules, OSHA, U. S. Dept, of Labor Fed. Reg. Vol. 40, No. 197, 10/9/75 Excerpt: The proposed standard would, among other things, lower the permissible exposure to 500,000 fibers per cubic meter (0.5 asbestos fibers per cubic centimeter) for an 8-hour time-weighted average exposure, and likewise reduce the permissible ceiling exposure to 5 million asbestos fibers per cubic meter (5 asbestos fibers per cubic centimeter) for any period not exceeding 15 minutes. Asbestos Industry Response to OSHA on 0.5-fiber/cc standard. (4/9/76) Re-examination and Update of Information on the Health Effects of Occupational Exposure to Asbestos (by NIOSH) (12/1976 Recommended Standard - The above document recommends a 0.1-fiber/cc standard (100,000 fibers per cubic meter). CTD002123 FIBER STANDARD General Information page 2 0.1-fiber/cc (continued) Consad Research Corporation - Work Plan Statement of Work for a Supplemental Analysis of the Technological Feasibility and Economic implications of a 0.1 Fiber per Cubic centimeter Exposure Limit for Asbestos (Received March 1977; Report not dated.) CTD002124