Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7783–41–7
NIOSH REL: 0.05 ppm (0.1 mg/m3) CEILING
Current OSHA PEL: 0.05 ppm (0.1 mg/m3) TWA
1989 OSHA PEL: 0.05 ppm (0.1 mg/m3) CEILING
1993-1994 ACGIH TLV: 0.05 ppm (0.11 mg/m3) CEILING
Description of substance: Colorless gas with a peculiar, foul odor.
LEL: . . Nonflammable Gas
Original (SCP) IDLH: 0.5 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Deichmann and Gerarde  that oxygen difluoride is a strong irritant to the entire respiratory tract and causes pulmonary edema and hemorrhage when inhaled for a few hours at 0.5 ppm. Development of pulmonary signs leading to death may be delayed several hours after the exposure [Deichmann and Gerarde 1969]. In addition, AIHA  reported that the Committee on Toxicology of the National Research Council recommended an Emergency Exposure Limit (EEL) of 0.5 ppm for a 10-minute exposure. This EEL is supposed to be for exposures that are “rare in the lifetime of an individual and permit some degree of reversible injury short of incapacitation” [Smyth 1966].
Existing short-term exposure guidelines: National Research Council (NRC) Emergency Exposure Limits (EELs) recommended to military and space agencies [Smyth 1966]:
10-minute EEL: 0.5 ppm
30-minute EEL: 0.2 ppm
60-minute EEL: 0.1 ppm
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50 (ppm)||LCLo (ppm)||Time||Adjusted 0.5-hr LC (CF)||Derived value|
|Darmer et al. 1972Darmer et al. 1972
Darmer et al. 1972
Darmer et al. 1972
|1 hr1 hr
|3.3 ppm (1.25)1.9 ppm (1.25)
33 ppm (1.25)
20 ppm (1.25)
|0.3 ppm0.2 ppm
Human data: Oxygen difluoride is a strong irritant to the entire respiratory tract and causes pulmonary edema and hemorrhage when inhaled for a few hours at 0.5 ppm [Deichmann and Gerarde 1969].
|Revised IDLH: 0.5 ppm [Unchanged]Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Deichmann and Gerarde 1969], the original IDLH for oxygen difluoride (0.5 ppm) is not being revised at this time.|
1. AIHA . Oxygen difluoride. In: Hygienic guide series. Am Ind Hyg Assoc J 28:194-196.
2. Darmer KI Jr, Haum CC, MacEwen JD . The acute inhalation toxicology of chlorine pentafluoride. Am Ind Hyg Assoc J 33:661-668.
3. Deichmann WB, Gerarde HW . Oxygen difluoride (OF2). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 444.
4. Smyth HF Jr . Military and space short-term inhalation standards. Arch Environ Health 12:488-490.