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Chemical Sampling Information (CSI)
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General Description

Synonyms: Nitrogen monoxide; Diesel Exhaust Component

OSHA IMIS Code Number: 1890

Chemical Abstracts Service (CAS) Registry Number: 10102-43-9

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: QX0525000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1660 124

NIOSH Pocket Guide to Chemical Hazards, Nitric oxide: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Z-1 Table -- 25 ppm, 30 mg/m3 TWA

Construction Industry: 29 CFR 1926.55 Appendix A -- 25 ppm, 30 mg/m3 TWA

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 25 ppm, 30 mg/m3 TWA

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 25 ppm, 31 mg/m3 TWA; BEIM

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 25 ppm, 30 mg/m3 TWA

Health Factors

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 100 ppm

Potential Symptoms: Eye, nose, throat, wet skin irritation; cough, shortness of breath, pulmonary edema (may be delayed); methemoglobinemia, cyanosis; headache; abdominal pain, nausea; confusion, drowsiness, convulsions, unconsciousness

Health Effects: Irritation-Eyes, Nose, Throat, Skin---Marked (HE14); Methemoglobinemia (HE13); CNS effects (HE7); Delayed lung damage (HE10)

Affected Organs: Eyes, skin, respiratory system, blood, CNS


  1. Nitric oxide is synthesized in the body from the amino acid L-arginine and exerts a variety of actions, some of which are beneficial (e.g., maintenance of normal kidney function), while others could be pathological (e.g., facilitation of lung damage by respirable particulates).
  2. Nitric oxide produced by an inducible form of nitric oxide synthase is postulated to have a causative role in the development of lung damage from exposure to silica, asbestos, and ozone, possibly via the formation of peroxynitrite, which reacts with.tyrosine in proteins.
  3. Increased nitric oxide in expired air has also been reported for susceptible workers exposed to latex, various diisocyanates and solvents. However, the concentrations in the expired air (means < 20 ppb) of these workers is far less than the concentration of nitric oxide (20 ppm) used clinically to improve pulmonary gas exchange in neonates, as well as concentrations used in adults with acute lung injury or acute respiratory distress syndrome.

Literature Basis:

  • NIOSH Pocket Guide to Chemical Hazards: Nitric oxide.
  • International Chemical Safety Cards (WHO/IPCS/ILO): Nitric oxide.
  • Barbinova, L. and Baur, X.: Increase in exhaled nitric oxide (eNO) after work-related isocyanate exposure. Int. Arch. Occup. Environ. Health 79(5): 387-395, 2006.
  • Baur, X. and Barbinova, L.: Latex allergen exposure increases exhaled nitric oxide in symptomatic healthcare workers. Eur. Respir. J. 25(2): 309-316, 2005.
  • Clark, R.H., et al.: Low-dose nitric oxide therapy for persistent pulmonary hypertension of the newborn. N. Engl. J. Med. 342(7): 469-474, 2000.
  • Griffiths, M.J.D. and Evans, T.W.: Inhaled nitric oxide therapy in adults. N. Engl. J. Med. 353(25): 2683-2695, 2005.
  • Maniscalco, M., Grieco, L., Galdi, A., Lundberg, J.O. and Sofia, M.: Increase in exhaled nitric oxide in shoe and leather workers at the end of the work-shift. Occup. Med. (Lond.) 54(6): 404-407, 2004.
  • Morishita, T., et al.: Nephrogenic diabetes insipidus in mice lacking all nitric oxide synthase isoforms. Proc. Natl. Acad. Sci. USA 102(30): 10616-10621, 2005.
  • Pohanish, R.P. (editor): Nitrogen Dioxide. Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1691-1694.
  • Zeidler, P.C. and Castranova, V: Role of nitric oxide in pathological responses of the lung to exposure to environmental/occupational agents. Redox. Rep. 9(1): 7-18, 2004.

Date Last Revised: 06/28/2006

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Two Glass Tubes each containing 400 mg Triethanolamine-impregnated Molecular Sieve separated by an Oxidizer tube containing 1 gm of a Chromate compound
    analytical solvent: 1.5% Triethanolamine solution
    maximum volume: 6 Liters
    maximum flow rate: 0.025 L/min
    current analytical method: Ion Chromatography; IC
    method reference: OSHA Analytical Method (OSHA ID-190)
    method classification: Fully Validated
    note: Submit as separate sample. First TEA tube collects NO2, second TEA tube collects NO. Carefully label tubes before shipping to the Salt Lake Technical Center. Do not submit oxidizer tube to the Salt Lake Technical Center.

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