Beryllium: Hazards evaluation, facility classification, consequence analysis of releases during potential accidents, and protection of public and workers

摘要

Comprehensive literature searches on beryllium (Be) and information on the particle size distribution of Be powder (Mishima et al.) indicate that the new airborne release fraction/respirable fraction (ARF/RF) values for large coherent pieces, turnings/swarfs, chips/powder, and dust are several orders of magnitude lower for explosion, fire, and spill (e.g., 1E-2,1.5E-5, 1E-6) than earlier estimates based on DOE-HDBK-3010.3 This implies a lower consequence exposure and thus an increase in threshold limit or lower facility hazard classification (High-Moderate-Low), and less risk of exposure to workers and public during these accident scenarios. This is demonstrated by a case study of using 100 lbs chips/powder under various accident conditions (explosion, fire, and spill) in standard terrain (rural) and city terrain (urban) to assess the relative concentrations to a receptor at different distances, using EPIcode (Emergency Prediction Information Code) dispersion model.rnBeryllium aerosol exposure can cause: (1) acute exposure (short term) from Emergency Response Planning Guideline-3, -2 (ERPG-3, -2) levels; and (2) chronic (long term) from sensitization and chronic beryllium disease (CBD). Per 40 CFR 61.32, the Environmental Protection Agency (EPA) Be emission standard limit to protect the public (no CBD) is 0.01 μg/m~3 on a 30-day time weighted average (TWA). Facility hazard classifications require modeling to be performed to establish a distance beyond which the public is protected. A case study using 100 lbs chip/powder release with conservative assumptions (e.g., standard, term release) shows that the public is protected beyond 200 m.rnThe American Conference of Government Industrial Hygienists (ACGIH) and Occupational Safety and Health Administration (OSHA) adopted exposure threshold limit value for workers at 2.0 μg/m~3, based on 8-hr TWA. However, 10 CFR 850 Rule on CBD and Prevention Program requires a protection at 0.2 μg/m~3 (8 h TWA), to further mitigate or prevent any health effects or CBD. Thus, 40 CFR 61.32, ACGIH and OSHA guide, and 10 CFR 850 Rule, coupled with the worker protection program and adequate safety controls, provide adequate protection from the CBD to the workers and public.