effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure.
AEGL-2 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape.
AEGL-3 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience life-threatening health effects or death.
Airborne concentrations below the AEGL-1 represent exposure concentrations that could produce mild and progressively increasing but transient and nondisabling odor, taste, and sensory irritation or certain asymptomatic, nonsensory effects. With increasing airborne concentrations above each AEGL, there is a progressive increase in the likelihood of occurrence and the severity of effects described for each corresponding AEGL. Although the AEGL values represent threshold concentrations for the general public, including susceptible subpopulations, such as infants, children, the elderly, persons with asthma, and those with other illnesses, it is recognized that individuals, subject to idiosyncratic responses, could experience the effects described at concentrations below the corresponding AEGL.
Perchloryl fluoride is a colorless, stable gas. It is used as a fluorinating agent, an oxidant in rocket fuels, and a gaseous dielectric for transformers. It is prepared by electrolysis of a saturated solution of sodium perchlorate in anhydrous hydrofluoric acid. Perchloryl fluoride is a strong oxidizer, and is strongly irritating to the eyes, mucous membranes, and lungs. Its systemic effects include induction of methemoglobinemia.
No human data were available for developing AEGL values, and only two relevant reports of studies in animals were found. Greene et al. (1960) performed several experiments in dogs, rats, mice, and guinea pigs. In acute studies with dogs, animals were treated with perchloryl fluoride at 224-622 ppm for 4 h, and hemoglobin and methemoglobin concentrations were evaluated. In studies with rats and mice, only 4-h LC50 (lethal concentration, 50% lethality) values were reported. Repeat-exposure studies in dogs, rats, mice, and guinea pigs also were performed. In the second report, mortality values were presented for rats at several time points, but details of the exposures to perchloryl fluoride were not included (Dost et al. 1974). No information relevant to time-scaling AEGL values for perchloryl fluoride was found.
The AEGL-1 values were derived from a study in which dogs and rats were exposed to perchloryl fluoride at 24 ppm for 6 h/day, 5 days/week for 26 weeks. All animals survived and no irritation or clinical signs of toxicity were