Abstract: Chemical Toxicity of uranium hexafluoride (UF₆) should be evaluated in addition to the effects of radiation in consequence assessment of UF₆ accidental release. The hazard of UF₆ accidental release would be underestimated when the half lethal concentration was used as the criteria for chemical toxicity assessment. In the environmental impact assessment for UF₆ accidental release, the health impact on public surrounding the site of accident should be considered besides the lethality of the released chemicals. Several series of chemical limits have been proposed by EPA, AIHA etc. The protective action criteria values (PACs) proposed by DOE are recommended for consequence assessment of the UF₆ accidental release.

Key words: UF₆ accidental release, consequence assessment, concentration limit