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Nitromethane
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 75–52–5
NIOSH REL: The 1989 OSHA PEL may not be protective to workers.
Current OSHA PEL: 100 ppm (250 mg/m3) TWA
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 100 ppm (250 mg/m3) TWA
Description of substance: Colorless, oily liquid with a disagreeable odor.
LEL:. . 7.3% (10% LEL, 7,300 ppm)
Original (SCP) IDLH: 1,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Browning [1965] that with concentrations above 1,000 ppm, if the product of this and the time of exposure was greater than 1 (e.g., 1,000 ppm for 3 hours) some of the animals, including 1 monkey, died. Also, AIHA [1961] reported severe eye irritation at 500 ppm [Machle et al. 1940]. [Note: The statement by Browning [1965] regarding the product of the concentration and the time of exposure is apparently in error; the value “greater than 1” should probably be “greater than 1,000”.]
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 |
|---|---|---|---|---|---|---|
| MouseMonkey
Rabbit Rabbit |
Izmerov et al. 1982Skinner 1947
Weatherby 1955 Weatherby 1955 |
———-
—– —– |
7,0871,000
2,500 5,000 |
2 hr?
12 hr 6 hr |
11,339 ppm (1.6)?
7,250 ppm (2.9) 11,500 ppm (2.3) |
1,134 ppm?
725 ppm 1,150 ppm |
Lethal dose data:
| Species | Reference | Route | LD50 (mg/kg) | LDLo (mg/kg) | Adjusted LD | Derived value |
|---|---|---|---|---|---|---|
| RabbitRat
Mouse Dog |
Machle et al. 1940Subbotin 1967
Subbotin 1967 Weatherby 1955 |
oraloral
oral oral |
—–940
950 —– |
750—–
—– 125 |
2,067 ppm2,590 ppm
2,618 ppm 344 ppm |
207 ppm259 ppm
262 ppm 34 ppm |
Human data: None relevant for use in determining the revised IDLH.
| Revised IDLH: 750 ppmBasis for revised IDLH: The revised IDLH for nitromethane is 750 ppm based on acute inhalation toxicity data in animals [Weathery 1955]. |
REFERENCES:
1. AIHA [1961]. Nitromethane. In: Hygienic guide series. Am Ind Hyg Assoc J 22:518-520.
2. Browning E [1965]. Toxicity and metabolism of industrial solvents. New York, NY: Elsevier Publishing Company, p. 282.
3. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 93.
4. Machle W, Scott EW, Treon J [1940]. The physiological response of animals to some simple mononitroparaffins and to certain derivatives of these compounds. J Ind Hyg Toxicol 22(8):315-332.
5. Skinner JB [1947]. The toxicity of 2-nitropropane. Ind Med 16:441-443.
6. Subbotin VG [1967]. Hygienic assessment of nitromethane and ether nitroparaffins in connection with sanitary protection of water bodies. Gig Sanit 32(9):9-13 (in Russian).
7. Weatherby JH [1955]. Observations on the toxicity of nitromethane. AMA Arch Ind Health 11:102-106.