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Chemical Sampling Information (CSI)
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General Description

Synonyms: Nitrous Acid, Sodium Salt; Anti-rust; Diazotizing Salts; Erinitrit; Filmerine

OSHA IMIS Code Number: S236

Chemical Abstracts Service (CAS) Registry Number: 7632-00-0

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: RA1225000

Chemical Description and Physical Properties:

white or slightly yellow, hydroscopic granules, rods or powder
molecular weight: 69.00
molecular formula: NaNO2
boiling point: 320°C
melting point: 271°C

Health Factors

Potential Symptoms: Irritation of eyes, nose, throat, lungs; cyanosis (blue lips, fingernails, skin); headache, cough, weakness, dizziness, nausea; confusion; convulsions, unconsciousness; eye redness, pain; skin, dryness, cracking, dermatitis; pulmonary edema.

Health Effects: Irritation-Eyes, Nose, Throat, Skin---Mild (HE16); Lung edema (HE11); Methemoglobinemia (HE13)

Affected Organs: Eyes, CNS, respiratory system, blood


  1. OSHA does not have a PEL for sodium nitrite.
  2. Sodium nitrite is listed by the FDA as a prior-sanctioned (by the USDA) food ingredient in the production (or curing) of red meat and poultry products (21 CFR 181.33 and 181.34). It is also regulated as an additive (up to 20 ppm) to canned pet food containing fish, meat, and their byproducts (21 CFR 573.700).
  3. Nitrite can be converted in the body to nitric oxide, a potent vasodilator with other physiological effects, such as increasing mucous production by the gastric mucosa.
  4. Sodium nitrite is used in combination with sodium thiosulfate for treatment of cyanide poisoning. Sodium nitrite has also been suggested as an antidote for hydrogen sulfide poisoning.

Literature Basis:

  • International Chemical Safety Cards (WHO/IPCS/ILO): Sodium nitrite.
  • NIOSH: Nitrous acid, sodium salt. The Registry of Toxic Effects of Chemical Substances (RTECS#: RA1225000).
  • Baskin, S.I., Horowitz, A.M. and Nealley, E.W.: The antidotal action of sodium nitrite and sodium thiosulfate against cyanide poisoning. J. Clin. Pharmacol. 32(4): 368-375, 1992.
  • Bradberry, S.M.: Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue. Toxicol. Rev. 22(1): 13-27, 2003.
  • Gladwin, M.T.: Haldane, hot dogs, halitosis, and hypoxic vasodilation: the emerging biology of the nitrite anion. J. Clin. Invest. 113(1): 19-21, 2004.
  • Hall, A.H. and Rumack, B.H.: Hydrogen sulfide poisoning: an antidotal role for sodium nitrite? Vet. Hum. Toxicol. 39(3): 152-154, 1997.
  • Mensinga, T.T., Speijers, G.J. and Meulenbelt, J.: Health implications of exposure to environmental nitrogenous compounds. Toxicol. Rev. 22(1): 41-51, 2003.
  • Pohanish, R.P. (editor): Potassium Nitrite. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1927-1929.
  • Zhu, S., Ware, L.B., Geiser, T., Matthay, M.A. and Matalon, S.: Increased levels of nitrate and surfactant protein A nitration in the pulmonary edema fluid of patients with acute lung injury. Am. J. Respir. Crit. Care Med. 163(1): 166-172, 2001.

Date Last Revised: 07/27/2004

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Mixed Cellulose Ester Filter (MCEF) 0.8 microns
    maximum volume: 960 Liters
    maximum flow rate: 2.0 L/min
    current analytical method: Ion Chromatography; IC
    method reference: OSHA Salt Lake Technical Center In-House File
    method classification: Not Validated
    alternate analytical method: Atomic Absorption Spectroscopy; AAS
    method reference: OSHA Salt Lake Technical Center In-House File
    method classification: Not Validated
    note: When the analysis of a compound is requested and elemental analysis is performed, results are reported as the compound. Submit as a separate sample.

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