Chlorine dioxide

CAS number: 10049–04–4

NIOSH REL: 0.1 ppm (0.3 mg/m³) TWA, 0.3 ppm (0.9 mg/m³) STEL

Current OSHA PEL: 0.1 ppm (0.3 mg/m³) TWA

1989 OSHA PEL: 0.1 ppm (0.3 mg/m³) TWA, 0.3 ppm (0.9 mg/m³) STEL

1993-1994 ACGIH TLV: 0.1 ppm (0.28 mg/m³) TWA, 0.3 ppm (0.83 mg/m³) STEL

Description of Substance: Yellow to red gas or a red-brown liquid (below 52 F) with an unpleasant odor similar to chlorine and nitric acid.

LEL: . . Unknown

Original (SCP) IDLH: 10 ppm

Basis for original (SCP): IDLH AIHA [1958] reported that rats exposed repeatedly to about 10 ppm for 4 hours daily died, whereas those exposed to about 0.1 ppm, 5 hours daily for 10 weeks, showed no detectable effects [Dalhamn 1957]. AIHA [1958] also reported that animals survived 2-hour exposures to 20 ppm, though some species exhibited symptoms [Gloemme and Lundgren 1957]. Elkins [1950] stated that 5 ppm is definitely irritating and 2 cases of illness (1 fatal) resulted from exposure to less than 19 ppm. AIHA [1958] reported that delayed deaths occur in animals after single exposures to 150 to 200 ppm for less than 1 hour [Gloemme and Lundgren 1957]. Based on the data cited above, an IDLH of 10 ppm is chosen.

Short-term exposure guidelines None developed

ACUTE TOXICITY DATA

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat	Dalhamn 1957	-----	260	2 hr	416 ppm (1.6)	42 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat	Abdel-Rahman et al. 1982	oral	292	-----	729 ppm	73 ppm

Human data: It has been reported that 5 ppm is definitely irritating and that 19 ppm caused the death of one worker inside a tank (time of exposure was not specified) [Elkins 1950].

Revised IDLH: 5 ppm Basis for revised IDLH: The revised IDLH is 5 ppm based on acute inhalation toxicity data in humans [Elkins 1950].

REFERENCES:

1. Abdel-Rahman MS, Gerges SE, Alliger H [1982]. Toxicity of alcide. J Appl Toxicol 2(3):160-164.

2. AIHA [1958]. Chlorine dioxide. In: Hygienic guide series. Am Ind Hyg Assoc J 19:261-262.

3. Dalhamn T [1957]. Chlorine dioxide: toxicity in animal experiments and industrial risks. AMA Arch Ind Health 15(2):101-107.

4. Elkins HB [1950]. Chlorine dioxide, ClO₂. In: The chemistry of industrial toxicology. New York, NY: John Wiley & Sons, Inc., pp. 87-88.

5. Gloemme J, Lundgren KD [1957]. Health hazards from chlorine dioxide. AMA Arch Ind Health 16:169-176.