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 levels 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 AEGLs represent threshold levels 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.
The halogen bromine (Br2) is a dark reddish-brown volatile liquid at room temperature. Its oxidizing potential lies between that of chlorine and iodine. Bromine is used as a water disinfectant, for bleaching fibers, and in the manufacture of medicinal bromine compounds, dyestuffs, flame retardants, agricultural chemicals, inorganic bromide drilling fluids, and gasoline additives.
Bromine is a skin, eye, and respiratory-tract irritant. Inhalation causes respiratory-tract irritation and pulmonary edema. Although accidental human exposures have occurred, concentrations were either not reported or were judged unreliable. The data on the inhalation toxicity of bromine are sparse and, at times, conflicting. Aside from old and anecdotal information, the database is limited to one study with human subjects and two lethality studies with the mouse as the test species. One of the lethality studies (Bitron and Aharonson 1978) provided data sufficient for derivation of the relationship between concentrations that result in lethality (LC50 values [concentration with 50% lethality]) and exposure duration: C2.2 × t = k (chemical concentration in air with a chemical-specific exponent applied to a specific end point × exposure time = response).
The AEGL-1 was based on exposures of 20 healthy human subjects to concentrations of 0.1 to 1.0 ppm for at least 30 min (Rupp and Henschler 1967). Eye irritation, but not nose or throat irritation, occurred during a 30-min exposure at 0.1 ppm. At concentrations of ≥0.5 ppm, there was a stinging and burning sensation of the conjunctiva. The 30-min exposure to 0.1 ppm, which caused