OSHA's current limits for beryllium are 0.002 mg/m3 as an 8-hour TWA, 0.005 mg/m3 as a 30-minute STEL, and 0.025 mg/m3 as a ceiling. OSHA is retaining these limits in the final rule. The ACGIH has a TLV-TWA for beryllium of 0.002 mg/m 3. NIOSH (1977o; Baier 1977b/Ex. 1-831) recommends a ceiling limit of 0.5 ug/m3 (0.0005 mg/m3). Beryllium is a hard, brittle, gray-white metal.
The ACGIH recommendation is based on human evidence describing nonmalignant respiratory disease and berylliosis associated with exposure to beryllium. Because of the uncertainty regarding the concentrations of beryllium necessary to produce chronic respiratory disease, and because of the serious nature of the disease, the ACGIH set a TLV-TWA of 0.002 mg/m3.
At the time of publication of NIOSH's criteria document on beryllium (NIOSH 1972a, as cited in ACGIH 1986/Ex. 1-3, p. 56), NIOSH judged the evidence on beryllium-related cancer to be equivocal. In testimony at OSHA's 1977 hearing on a standard for beryllium, however, NIOSH presented additional epidemiologic and animal evidence indicating that beryllium is carcinogenic. In particular, NIOSH (1977o; Baier 1977b/Ex. 1-831) cited the studies of Bayliss and Wagoner (1977) and Mancuso (1977), which showed significant increases in bronchogenic cancer among beryllium-exposed workers. NIOSH therefore recommended at the 1977 hearing that exposure to beryllium not exceed the reliable limit of detection of 0.5 ug/m3 (NIOSH 1977o; Baier 1977b/Ex. 1-831).
George M. Talley and Michael C. Garcia, Industrial Hygienists for the Los Alamos National Laboratory (Ex. 3-1095), commented that beryllium should not be included in the group of potential carcinogens in this rulemaking because OSHA is not revising its limits for beryllium on the basis of carcinogenicity. As discussed in other sections of this preamble, OSHA's classification of substances in this preamble is not meant to have regulatory implications but to facilitate generic rulemaking. OSHA also notes, as do Mr. Talley and Mr. Garcia, that the ACGIH has designated beryllium as a potential (A2) human carcinogen.
Representatives of the International Chemical Workers Union (Tr. p. 9-217) and the AFL-CIO (Ex. 194) urged OSHA to issue a standard for beryllium based on the NIOSH REL. As explained in the proposal and in Section III of this preamble, however, OSHA has used its priority-setting authority to focus this rulemaking on substances selected for inclusion on the basis of certain decision rules. Beryllium is a substance with an extensive rulemaking history, in that OSHA has previously issued an NPRM and developed an extensive record for beryllium. The Agency determined that, because of this extensive prior history, beryllium presents issues that are too complex for a decision at this time.
The ACGIH TLV of 0.002 mg/m3 (TWA) was judged in the NPRM to be less stringent than OSHA's existing PELs. NIOSH (Ex. 8-47, Table N6B) did not concur with OSHA's proposal to retain the existing PELs. As OSHA explained in the NPRM, the NIOSH REL is based on analytical and sampling limits of detection, an approach to limit-setting that does not necessarily satisfy OSHA's requirements regarding significant risk and feasibility. In the final rule, OSHA is retaining the Agency's PELs of 0.002 mg/m3 TWA, 0.005 mg/m3 as a 30-minute STEL, and 0.025 mg/m3 as a ceiling for beryllium and compounds.