Nitric oxide

IDLH Documentation
CAS number: 10102­43­9

NIOSH REL: 25 ppm (30 mg/m3) TWA

Current OSHA PEL: 25 ppm (30 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 25 ppm (31 mg/m3) TWA

Description of substance: Colorless gas.

LEL: . . . Nonflammable Gas

Original (SCP) IDLH: 100 ppm

Basis for original (SCP) IDLH: No useful data on acute inhalation toxicity are available on which to base the IDLH for nitric oxide. The chosen IDLH, therefore, is based on the statement by Sax [1975] that 100 to 150 ppm oxides of nitrogen are dangerous for short exposures of 30 to 60 minutes. The chosen IDLH seems reasonable because NIOSH [1976] cited a rabbit 15­minute LC50 of 315 ppm for nitric oxide [Carson et al. 1962].

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
Rabbit

Mouse

Rat

Mouse

Carson et al. 1962

Flury and Zernik 1931

Ivanov and Szubaev 1979

Pflesser 1935

315

-----

854

320
-----

2,500

-----

-----
15 min

12 min

4 hr

?
249 ppm (0.79)

1,850 ppm (0.74)

1,709 ppm (2.0)

?
25 ppm

185 ppm

171 ppm

?

Other animal data: Guinea pigs have survived an exposure at 175 ppm for an unstated period [Bodansky 1951].

Human data: It has been stated that exposures to oxides of nitrogen between 100 and 150 ppm are dangerous for exposures of 30 to 60 minutes [Sax 1975].


Revised IDLH: 100 ppm [Unchanged]

Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Sax 1975], the original IDLH for nitric oxide (100 ppm) is not being revised at this time.

REFERENCES:

1. Bodansky O [1951]. Methemoglobinemia and methemoglobin­producing compounds. Pharmacol Rev 3:144­195.

2. Carson TR, Rosenholtz MS, Wilinski FT, Weeks MH [1962]. The responses of animals inhaling nitrogen dioxide for single, short­term exposures. Am Ind Hyg Assoc J 23:457­462.

3. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch­ und staubarten. Berlin, Germany: Verlag von Julius Springer, pp. 157­165 (in German).

4. Ivanov NG, Szubaev EN [1979]. About the limitation of the content of nitrogen dioxide in the air of the working zone. Toksikol Nov Prom Khim Vesh 15:53­58 (in Russian).

5. NIOSH [1976]. QX05250. Nitrogen monoxide. In: Registry of toxic effects of chemical substances, 1976 ed. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 76­191, p. 780.

6. Pflesser G [1935]. The significance of nitric oxide in poisoning by nitrous gases. Arch Exp Pathol Pharmakol 179:545­557 (in German).

7. Sax NI [1975]. Nitric oxide. In: Dangerous properties of industrial materials. 4th ed. New York, NY: Van Nostrand Reinhold Company, pp. 961­962.
Go back to the Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)