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Iodine
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7553–56–2
NIOSH REL: 0.1 ppm (1 mg/m3) CEILING
Current OSHA PEL: 0.1 ppm (1 mg/m3) CEILING
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 0.1 ppm (1 mg/m3) CEILING
Description of substance: Violet solid with a sharp, characteristic odor.
LEL:. . Noncombustible Solid
Original (SCP) IDLH: 10 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with bromine which has an IDLH of 10 ppm.
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 | Izmerov et al. 1982 | —– | 76 | 1 hr | 95 ppm (1.25) | 9.5 ppm |
Lethal dose data:
| Species | Reference | Route | LD50(mg/kg) | LDLo(mg/kg) | Adjusted LD | Derived value |
|---|---|---|---|---|---|---|
| RatMouse
Rabbit Dog |
Angelis 1979Angelis 1979
Angelis 1979 Flury and Zernik 1935 |
oraloral
oral oral |
14,00022,000
10,000 —– |
———-
—– 800 |
9,289 ppm14,597 ppm
6,635 ppm 531 ppm |
929 ppm1,460 ppm
664 ppm 53 ppm |
Human data: It has been reported that work was difficult but possible at 0.15 to 0.2 ppm and that work was impossible at 0.3 ppm [Flury and Zernik 1931]. Exposures to 1 ppm have been reported to be highly irritating [Casarett 1975]. Eye irritation was experienced at 1.63 ppm after 2 minutes [ACGIH 1980]. It has been stated that iodine-containing materials appear to be more toxic than analogous bromine or chlorine-containing materials [ILO 1971]. The lethal oral dose has been reported to be 2 to 3 grams [Moore 1938]. [Note: An oral dose of 2 to 3 grams is equivalent to a worker being exposed to 126 to 190 ppm for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]
| Revised IDLH: 2 ppmBasis for revised IDLH: The revised IDLH for iodine is 2 ppm based on acute inhalation toxicity data in humans [ACGIH 1980]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 2 ppm. However, since it has been reported that iodine-containing materials are more toxic than bromine-containing materials, a revised IDLH of 2 ppm for iodine is appropriate since the revised IDLH for bromine is 3 ppm. |
REFERENCES:
1. ACGIH [1980]. Iodine. In: Documentation of the threshold limit values. 4th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienist, p. 230.
2. Angelis L [1979]. Iopamidol. Drugs of the Future 4:876-881.
3. Casarett LJ [1975]. Toxicology of the respiratory system. In: Toxicology. The basic science of poisons. Casarett LJ, Doull J, eds. New York, NY: Macmillan, pp. 201-224.
4. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 309 (in German).
5. Flury F, Zernik F [1935]. Zusammenstellung der toxischen und letalen dosen für die gebräuchlichsten gifte und versuchstiere. Abder Hand Biol Arbeitsmethod 4:1289-1422 (in German).
6. ILO [1971]. Iodine. In: Encyclopaedia of occupational health and safety. 2nd ed. Vol. I (A-K). Geneva, Switzerland: International Labour Office, pp. 739-740.
7. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 76.
- Moore M [1938]. The ingestion of iodine as a method of attempted suicide. N Eng J Med 219:383-388.