Inventory- or Consequence-Based Evaluation of Hazardous Chemicals: Recommendations for DOE Facility Safety Analysis
Two different methods are in use for establishing the safety of facilities, processes, or operations involving hazardous chemicals. One sets inventory limits using Occupational Safety and Health Administration (OSHA) threshold quantity (TQ), Environmental Protection Agency (EPA) Clean Air Act Amendment threshold quantity (CAA-TQ), threshold planning quantity (TPQ) or reportable quantity (RQ), values published in the Federal Register. The second method uses toxicological consequence estimates at different receptor points (e.g., facility boundary, 100 m, site boundary) of concentration limits established for this purpose. These include such parameters as EPA acute exposure guidance level (AEGL), emergency response planning guideline (ERPG), and immediately dangerous to life or health (IDLH) values. Estimating the potential downwind concentrations of all chemicals on the OSHA Process Safety Management regulation TQ list compared these two methods. EPA CAA-TQ, TPQ, and RQ, values were extracted for these chemicals. Only 61 of the 128 unique chemicals with TQs also have CAA-TQs, 60 have TPQs, and 78 have RQs. Only 8 of 60 TQs are less than TPQ values for that chemical. Conservative release fractions (at 25 degrees C), and dispersion conditions were used to calculate potential airborne concentrations at 100 m downwind of the assumed release of TQ quantities of each chemical. These calculations were repeated for all chemicals on the TQ list that also had CAA-TQs, TPQs or RQs. These concentrations were compared with ERPG values wherever possible. Every TPQ to ERPG ratio was greater than unity. For RQs, none of 24 RQ to ERPG-1, 6 of 33 RQ to ERPG-2, and 11 of 33 RQ to ERPG-3, ratios were less than ten and only one was less than unity. In other words, severe health consequences could result from potential releases of many of these chemicals. These results demonstrate the undesirability of using regulatory quantities established for different purposes to include these chemicals in hazard assessments, or as inventory limits. It is recommended that concentration-limits established specifically for short-term acute exposures, such as AEGLs or ERPGs, be used in safety-related applications.These results demonstrate the undesirability of using regulatory quantities such as TQs or RQs, which were established for different purposes, in making decisions to include chemicals in hazard assessments, or as inventory limits. It is recommended that concentration-limits established specifically for short-term acute exposures, such as AEGLs or ERPGs, be used in safety-related applications. Since these concentration limits have so far been developed for only a small number of chemicals, temporary emergency exposure limits (TEELs), available on DOE-EH's chemical safety web page, can be used.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC09-96SR18500
- OSTI ID:
- 7963
- Report Number(s):
- WSRC-MS-98-00899; ON: DE00007963
- Resource Relation:
- Conference: 1999 Safety Analysis Working Group Workshop, Portland, OR (USA), 13-18 Jun 1999
- Country of Publication:
- United States
- Language:
- English
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