Applicability of airborne release fraction and respirable fraction values to particulate toxic chemical material releases at DOE sites

A survey of 14 Department of Energy (DOE) sites was performed to identify methodology used in the selection of airborne release fraction (ARF) and respirable fraction (RF) values for chemicals that are used to evaluate concentration exposures (i.e., consequences) for workers and public from accidental release of toxic chemical particulate material. Approximately half of the surveyed sites do not use ARF/RF values because they handle small quantities of chemicals, which are below the threshold planning quantities (TPQs) of 40 CFR 355 and threshold quantities (TQs) of 29 CFR 1910.119, where quantitative concentration (consequence) analysis is not usually performed. The sites that use ARF/RF values for chemicals typically use values that are based on DOE-HDBK-3010-941 that were developed for plutonium and uranium, which may not always be applicable and thus not be reliable. Guidance on ARF/RF use for toxic chemicals based on DOE-HDBK-3010-94 values is discussed in terms of density, particle size, deposition rate, and other properties.