An official website of the United States government

Nitrogen Dioxide

PubChem CID
3032552
Structure
Nitrogen Dioxide_small.png
Molecular Formula
Synonyms
  • NITROGEN DIOXIDE
  • 10102-44-0
  • Dioxide, Nitrogen
  • Peroxide, Nitrogen
  • nitrosooxidanyl
Molecular Weight
46.006 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-08-08
  • Modify:
    2025-01-18
Description
Nitrogen dioxide appears as a reddish brown gas or yellowish-brown liquid when cooled or compressed. Shipped as a liquefied gas under own vapor pressure. Vapors are heavier than air. Toxic by inhalation (vapor) and skin absorption. Noncombustible, but accelerates the burning of combustible materials. Cylinders and ton containers may not be equipped with a safety relief device.
Nitrogen Dioxide is found in the atmosphere as a key ingredient in photochemical formation of smog and acid rain, Nitrogen Dioxide is a poisonous gas that forms during combustion. Toxic at high concentrations, it reacts with moisture in the air to form nitric acid, highly corrosive and hazardous to plants and animals. (NCI04)
Nitrogen oxide (NO2). A highly poisonous gas. Exposure produces inflammation of lungs that may only cause slight pain or pass unnoticed, but resulting edema several days later may cause death. (From Merck, 11th ed) It is a major atmospheric pollutant that is able to absorb UV light that does not reach the earth's surface.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Nitrogen Dioxide.png

1.2 3D Status

Conformer generation is disallowed since MMFF94s unsupported atom valence

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 InChI

InChI=1S/NO2/c2-1-3
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.2 InChIKey

JCXJVPUVTGWSNB-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 SMILES

N(=O)[O]
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

NO2
Computed by PubChem 2.2 (PubChem release 2021.10.14)
NO2

2.3 Other Identifiers

2.3.1 CAS

10102-44-0

2.3.2 Deprecated CAS

119990-11-3, 127999-62-6, 2332895-81-3, 50443-93-1, 56003-83-9, 66252-28-6, 78246-05-6

2.3.3 European Community (EC) Number

2.3.4 UN Number

2.3.5 HMDB ID

2.3.6 ICSC Number

2.3.7 NCI Thesaurus Code

2.3.8 Nikkaji Number

2.3.9 RTECS Number

2.3.10 Wikidata

2.3.11 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • Dioxide, Nitrogen
  • Nitrogen Dioxide
  • Nitrogen Peroxide
  • Peroxide, Nitrogen

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
46.006 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3-AA
Property Value
-0.3
Reference
Computed by XLogP3 3.0 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
45.992903243 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
45.992903243 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
30.4 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
3
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
7.5
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Nitrogen dioxide appears as a reddish brown gas or yellowish-brown liquid when cooled or compressed. Shipped as a liquefied gas under own vapor pressure. Vapors are heavier than air. Toxic by inhalation (vapor) and skin absorption. Noncombustible, but accelerates the burning of combustible materials. Cylinders and ton containers may not be equipped with a safety relief device.
Yellowish-brown liquid or reddish-brown gas (above 70 degrees F) with a pungent, acrid odor; Note: In solid form (below 15 degrees F) it is found structurally as N2O4; [NIOSH]
REDDISH-BROWN GAS OR BROWN OR YELLOW LIQUID WITH PUNGENT ODOUR.
Yellowish-brown liquid or reddish-brown gas (above 70 °F) with a pungent, acrid odor.
Yellowish-brown liquid or reddish-brown gas (above 70 °F) with a pungent, acrid odor. [Note: In solid form (below 15 °F) it is found structurally as N₂O₂.]

3.2.2 Color / Form

Red to brown gas above 21.1 °C; brown liquid below 21.1 °C; colorless solid at approx -11 °C
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 896
Liquid below 21.15 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Yellowish-brown liquid or reddish-brown gas (above 70 °C) [Note: In solid form (below 15 °F) it is found structurally as N2O4]
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Brown gas; equilibrium with N2O4
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 4-79

3.2.3 Odor

Irritating odor
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Sweetish, acrid.
Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)
Pungent, acrid odor
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Healthy subjects can detect the odor of NO2, in some cases at concentrations below 188 ug/cu m (0.1 ppm).
WHO; Environ Health Criteria 188: Nitrogen Dioxide p.13 (1997)

3.2.4 Boiling Point

70.07 °F at 760 mmHg (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
21.15 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
21.2 °C
70 °F

3.2.5 Melting Point

15.3 °F (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
-9.3 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
-11.2 °C
15 °F

3.2.6 Solubility

Reacts with water (NIOSH, 2024)
Reacts with water
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 4-79
Soluble in concentrated sulfuric and nitric acids
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Solubility in water: reaction
Reacts

3.2.7 Density

1.448 at 68 °F (EPA, 1998) - Denser than water; will sink
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
1.448 at 20 °C/4 °C (liquid); 3.3 g/L at 21.3 °C (gas)
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Density: 1.880 g/L
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 4-79
Relative density (water = 1): 1.45 (liquid)
1.44 (liquid at 68 °F)
2.62(relative gas density)

3.2.8 Vapor Density

1.58 (EPA, 1998) - Heavier than air; will sink (Relative to Air)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
1.58 (Air = 1) (gas)
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Relative vapor density (air = 1): 1.58
2.62

3.2.9 Vapor Pressure

720 mmHg at 68 °F (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
900.0 [mmHg]
Vapor pressure = 400 MM HG @ 80 °C
Sax, N.I. Dangerous Properties of Industrial Materials. Vol 1-3 7th ed. New York, NY: Van Nostrand Reinhold, 1989., p. 2523
900 mm Hg at 25 °C
Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
Vapor pressure, kPa at 20 °C: 96
720 mmHg

3.2.10 Decomposition

When heated to decomposition it emits toxic fumes of /nitroxides/.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2678
Decomposes at 160 °C. Decomposes (reacts) with water.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 5th Edition Volume 1: A-H,Volume 2: I-Z. William Andrew, Norwich, NY 2008, p. 1868

3.2.11 Viscosity

0.0142 at 26.8 °C (gas): 0.42 CP at 20 °C (liquid)
Braker W, Mossman A; Matheson Gas Data Book 6th Ed p.531 (1980)

3.2.12 Corrosivity

Corrosive to steel when wet, but may be stored in steel cylinders when moisture content is 0.1% or less
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142

3.2.13 Heat of Vaporization

9.110 kcal/mole
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142

3.2.14 Ionization Potential

9.75 eV

3.2.15 Odor Threshold

Odor Threshold Low: 0.05 [mmHg]

Odor Threshold High: 0.14 [mmHg]

Odor threshold from AIHA (odor character = "bleach")

Low odor threshold 2.0 mg/cu m; High odor threshold 10.0 mg/cu m; Irritating concn 20.0 mg/cu m.
Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)

3.2.16 Refractive Index

INDEX OF REFRACTION: 1.40 @ 20 °C
Weast, R.C. (ed.) Handbook of Chemistry and Physics. 69th ed. Boca Raton, FL: CRC Press Inc., 1988-1989., p. B-111

3.2.17 Other Experimental Properties

Decomposes in water forming nitric acid and nitric oxide, reacts with alkalies to form nitrates and nitrites.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Does not burn, but supports the combustion of carbon, phosphorus, sulfur
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
1 mg/cu m = 0.532 ppm; 1 ppm = 1.88 mg/cu m at 25 °C, 760 mm Hg
Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982., p. 4098

3.3 Chemical Classes

Toxic Gases & Vapors -> Oxidizers

4 Spectral Information

4.1 Mass Spectrometry

4.1.1 GC-MS

1 of 2
Source of Spectrum
AA-0-15-2
Copyright
Copyright © 2020-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Source of Spectrum
NW-1721-0-0
Copyright
Copyright © 2020-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

6 Chemical Vendors

7 Pharmacology and Biochemistry

7.1 MeSH Pharmacological Classification

Oxidants, Photochemical
Compounds that accept electrons in an oxidation-reduction reaction. The reaction is induced by or accelerated by exposure to electromagnetic radiation in the spectrum of visible or ultraviolet light. (See all compounds classified as Oxidants, Photochemical.)

7.2 Absorption, Distribution and Excretion

Several reports suggest that nitrogen dioxide is absorbed in lungs and reacts with blood ... Nitrous fumes ... act chiefly on alveolar walls.
Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. III-321
50 to 60% of inspired nitrogen dioxide in rhesus monkeys was retained during quiet resp, the gas was distributed throughout lungs. Once absorbed, nitrogen dioxide or chem intermediates remained within lungs for prolonged periods after cessation of exposure, & dissemination to extrapulmonary sites occurred via blood stream.
GOLDSTEIN E ET AL; AM REV RESPIR DIS 115 (3): 403-12 (1977)
... Found that about 50% of nitrogen dioxide was absorbed in passage through the nose and throat of a rabbit. ... 50 to 60% of nitrogen dioxide was absorbed by monkeys exposed to 0.3 to 0.9 ppm of nitrogen dioxide. The radioactive tracer ... used remained in the lung for prolonged periods, with some spread to other tissues.
Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982., p. 4099
Nitrogen dioxide is partly dissolved in the mucus of the upper airways, but it is also fairly evenly distributed throughout the respiratory tract; it is furthur spread in the body by the circulatory system.
Linvall T; J Work Environ Health 11 (3): 10-28 (1985)
For more Absorption, Distribution and Excretion (Complete) data for Nitrogen dioxide (7 total), please visit the HSDB record page.

7.3 Metabolism / Metabolites

Inhalation of nitrogen dioxide (NO2) by mice administered orally amidopyrine (AP) and sodium nitrite resulted in increased biosynthesis of N-nitrosodimethylamine (NDMA), as determined by analysis using gas chromatography with thermal energy analyzer detector. These results were also confirmed indirectly in chronic experiments on rats using the system of biomarkers of NDMA formation (single-stranded DNA liver damages, alanine-aminotransferase, glutathione-S-transferase, and liver S9 fraction activity). The inhibition of NDMA metabolism by 4-methylpyrazol (4-MP) administration increases the sensitivity of NDMA biosynthesis assay in frozen whole-mouse powder. The results confirm that NO2 can serve as the precursor of nitrosamines.
Rubenchik BL et al; J Environ Pathol Toxicol Oncol 14 (2): 111-5 (1995)
Sprague-Dawley rats exposed to atmospheres containing low levels of nitrogen dioxide for 24 hr had increased levels of nitrate in their urine on the day of exposure & on the 3 subsequent days. Authors findings support the hypothesis that the major interaction of nitrogen dioxide in the lung is with readily oxidizable tissue components to form nitrite, & they estimate that 9.6 umol of nitrite is formed in the respiratory tract per ppm nitrogen dioxide 24 hr exposure.
SAUL RL, ARCHER MC; TOXICOL APPL PHARMACOL 67 (2): 284-91 (1983)
Nitrates and nitrites have been detected in the urine of animals after the inhalation of nitrogen dioxide.
Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982., p. 4099

7.4 Mechanism of Action

The lung can be exposed to a variety of reactive nitrogen intermediates through the inhalation of environmental oxidants and those produced during inflammation. Reactive nitrogen species (RNS) include, nitrogen dioxide (.NO2) and peroxynitrite (ONOO-). Classically known as a major component of both indoor and outdoor air pollution, .NO2 is a toxic free radical gas. .NO2 can also be formed during inflammation by the decomposition of ONOO- or through peroxidase-catalyzed reactions. Due to their reactive nature, RNS may play an important role in disease pathology. Depending on the dose and the duration of administration, .NO, has been documented to cause pulmonary injury in both animal and human studies. Injury to the lung epithelial cells following exposure to .NO2 is characterized by airway denudation followed by compensatory proliferation. The persistent injury and repair process may contribute to airway remodeling, including the development of fibrosis. To better understand the signaling pathways involved in epithelial cell death by .NO2 or otherRNS, ... cells /are exposed/ in culture to continuous gas-phase .NO2. Studies using the .NO2 exposure system revealed that lung epithelial cell death occurs in a density dependent manner. In wound healing experiments, .NO2 induced cell death is limited to cells localized in the leading edge of the wound. Importantly, .NO2-induced death does not appear to be dependent on oxidative stress per se. Potential cell signaling mechanisms ... include the mitogen activated protein kinase, c-Jun N-terminal Kinase and the Fas/Fas ligand pathways. During periods of epithelial loss and regeneration that occur in diseases such as asthma or during lung development, epithelial cells in the lung may be uniquely susceptible to death...
Persinger RL et al; Mol Cellular Biochem 234-235 (1-2): 71-80 (2002)
The biochemical mechanisms of nitrogen dioxide cellular injury ... One emphasizes lipid peroxidation, the other the oxidation of low molecular wt reducing substances & proteins. These need not be mutually exclusive. ... Nitrogen dioxide ... Initiate oxidation through free radicals ... Induction period ... Can be prolonged by vitamin E or other free radical scavenging agents. Polar nitrogen containing cmpd & peroxides are produced.
Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982., p. 4102

8 Use and Manufacturing

8.1 Uses

Sources/Uses
Generated from high temperature combustion; a common indoor air pollutant (gas ranges, kerosene heaters and improperly vented gas space heaters); occupational exposures have occurred after oxyacetylene welding, after underground blasting in mining operations, and after entering freshly filled farm silos. Other activities associated with increased NO2 levels include: glassblowing; operating motor vehicles indoors (including ice skating rink resurfacing machines); manufacture of nitric acid, oxidized cellulose compounds, lacquers and dyes, rocket propellants, and fertilizers; brazing; metal cleaning; rayon and food bleaching; fire fighting. [Rom, p. 1467]
Rom - Rom WN (ed). _Environmental and Occupational Medicine, _4th Ed. Philadelphia: Lippincott Williams & Wilkins, 2007., p. 1467
Industrial Processes with risk of exposure

Acid and Alkali Cleaning of Metals [Category: Clean]

Welding [Category: Weld]

Heat Treating [Category: Heat or Machine]

Electroplating [Category: Plate]

Metal Thermal Spraying [Category: Plate]

Petroleum Production and Refining [Category: Industry]

Pulp and Paper Processing [Category: Industry]

Gas Welding and Cutting [Category: Weld]

Mining [Category: Industry]

Firefighting [Category: Other]

Burning Natural Polymers [Category: Burn]

Burning Synthetic Polymers [Category: Burn]

Burning Celluloid [Category: Burn]

Farming (Respiratory Hazards) [Category: Industry]

Glass Manufacturing [Category: Industry]

Activities with risk of exposure

Ceramics making [Category: Hobbies]

Enameling [Category: Hobbies]

Glassblowing [Category: Hobbies]

Intalagio printing [Category: Hobbies]

Lithography printing [Category: Hobbies]

Smoking cigarettes [Category: Food & Drugs]

Burning biomass fuel for cooking and heating [Category: Environments]

Intermediate in nitric acid and sulfuric acid production. Has been used to bleach flour; used in nitration of organic cmpounds and explosives; in the manufacture of oxidized cellulose compounds (hemostatic cotton). Proposed as oxidizing agent in rocket propulsion.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Production of nitric acid, nitrating agent, oxidizing agent, catalyst, oxidizer for rocket fuels;,polymerization inhibitor for acrylates
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 896
Chemical intermediate (captive) for nitric acid; catalyst for sulfuric acid (chamber process); oxidizing agent for rocket fuels; calibration gas
SRI

8.1.1 Use Classification

Hazard Classes and Categories ->

8.2 Methods of Manufacturing

By oxidation of nitric acid.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 896

8.3 Formulations / Preparations

Commercial brown liquid under pressure is called nitrogen tetroxide ... an equilibrium mixture of NO2 and the colorless N2O4
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142
Grades: Pure, 99.5% min.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 896

8.4 General Manufacturing Information

EPA TSCA Commercial Activity Status
Nitrogen oxide (NO2): ACTIVE
Nitrogen dioxide is an ubiquitous product of combustion, occurring in exhaust from motor vehicles, emissions from the combustion of stationary fuel sources such as coal, oil or natural gas and various industrial sources
Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)

8.5 Sampling Procedures

PERSONAL SAMPLER FOR GASES IN AIR ADAPTED TO MEASUREMENT OF NITROGEN DIOXIDE.
PALMES ED ET AL; AM IND HYG ASSOC J 37 (10): 570-77 (1976)
ANALYTE: NITROGEN DIOXIDE; MATRIX: AIR; COLLECTION ON TEA /TRIETHANOLAMINE/-COATED MOLECULAR SIEVE, DESORPTION WITH TEA.
U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual of Analytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present., p. V4 S320
Sampler: Passive (Palmes tube with three triethanolamine-treated screens); Sampling time: Min: 15 minutes @ 5 ppm; Max: 8 hr @ 10 ppm. Sample stability: Use sampler within 1 mo after preparation; analyze within 1 month after sampling. Range studied: 1.2 to 80 ppm-hr (0.13 to 8.5 ug nitrogen dioxide per sample); Overall precision: 0.06.
U.S. Department of Health and Human Services, Public Health Service. Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods, 3rd ed. Volumes 1 and 2 with 1985 supplement, and revisions. Washington, DC: U.S. Government Printing Office, February 1984., p. V2 6700-1

9 Identification

9.1 Analytic Laboratory Methods

Method: NIOSH 6014, Issue 1; Procedure: visible absorption spectrophotometry; Analyte: nitrate ion; Matrix: air; Detection Limit: 1 ug nitrate ion/sample.
CDC; NIOSH Manual of Analytical Methods, 4th ed. Nitrogen Dioxide (10102-44-0). Available from, as of June 14, 2010: https://www.cdc.gov/niosh/docs/2003-154/
Method: OSHA ID-182; Procedure: ion chromatography; Analyte: nitrogen dioxide; Matrix: air; Detection Limit: qualitative 0.07 ppm/sample, quantitative 0.19 ppm/sample.
U.S. Department of Labor/Occupational Safety and Health Administration's Index of Sampling and Analytical Methods. Nitrogen Dioxide (10102-44-0). Available from, as of June 15, 2010: https://www.osha.gov/dts/sltc/methods/toc.html
MEASUREMENT OF SUB-PPB BY VOLUME LEVELS OF ATMOSPHERIC NITROGEN DIOXIDE SPECTROFLUOROMETRIC ANALYSIS.
AXELROD HD ET AL; ANAL CHEM 47 (12): 2021-3 (1975)
Analyte: nitrite ion; Matrix: air; Procedure: Visible absorption spectrophotometry; Range: 0.13-8.5 ug nitrogen dioxide/sample; Estimated LOD: 0.01 ug nitrogen dioxide/sample; Precision: 0.05. Interferences: In very dusty environments, particles may deposit on the inside surface of the samplers. Resuspension of the dust in the analytical reagent can give a positive bias in the spectrophotometric reading.
U.S. Department of Health and Human Services, Public Health Service. Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods, 3rd ed. Volumes 1 and 2 with 1985 supplement, and revisions. Washington, DC: U.S. Government Printing Office, February 1984., p. V2 6700-1
A REVIEW WITH 12 REFERENCES IS GIVEN OF CURRENTLY AVAILABLE TECHNIQUES FOR THE EST OF NITROGEN DIOXIDE CONCN IN AIR.
COLE HS, SUMMERHAYS JE; J AIR POLLUT CONTROL ASSOC 29 (8): 812-7 (1979)

9.2 NIOSH Analytical Methods

10 Safety and Hazards

10.1 Hazards Identification

ERG Hazard Classes
Toxic/poison by inhalation (TIH/PIH)

10.1.1 GHS Classification

1 of 5
View All
Pictogram(s)
Oxidizer
Compressed Gas
Corrosive
Acute Toxic
Signal
Danger
GHS Hazard Statements

H270 (99.6%): May cause or intensify fire; oxidizer [Danger Oxidizing gases]

H280 (83.2%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (36.1%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H330 (100%): Fatal if inhaled [Danger Acute toxicity, inhalation]

Precautionary Statement Codes

P220, P244, P260, P264, P264+P265, P271, P280, P284, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P320, P321, P363, P370+P376, P403, P403+P233, P405, P410+P403, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 244 reports by companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

10.1.2 Hazard Classes and Categories

Ox. Gas 1 (99.6%)

Press. Gas (Liq.) (83.2%)

Skin Corr. 1B (100%)

Eye Dam. 1 (36.1%)

Acute Tox. 2 (100%)

Gases under pressure

Oxidising gas - category 1

Acute toxicity - category 2

Skin corrosion - category 1B

10.1.3 NFPA Hazard Classification

1 of 2
View All
NFPA 704 Diamond
3-0-0
NFPA Health Rating
3 - Materials that, under emergency conditions, can cause serious or permanent injury.
NFPA Fire Rating
0 - Materials that will not burn under typical fire conditions, including intrinsically noncombustible materials such as concrete, stone, and sand.
NFPA Instability Rating
0 - Materials that in themselves are normally stable, even under fire conditions.

10.1.4 Highly Hazardous Substance

OSHA Highly Hazardous Chemicals, Toxics and Reactives
  • Chemical: Nitrogen Dioxide
  • Threshold: 250 [lb]
  • Note: Nitrogen Dioxide in quantities at or above above 250lb presents a potential for a catastrophic event as a toxic or reactive highly hazardous chemical.

10.1.5 Health Hazards

Severe exposures may be fatal. Contact may cause burns to skin and eyes. Contact with liquid may cause frostbite. This compound was reported to react with blood to form methemoglobin. The lowest lethal human inhalation dose has been reported at 200 ppm/1 min. (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 124 (Nitrogen dioxide)

· TOXIC and/or CORROSIVE; may be fatal if inhaled or absorbed through skin.

· Fire will produce irritating, corrosive and/or toxic gases.

· Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.

· Runoff from fire control or dilution water may cause environmental contamination.

10.1.6 Fire Hazards

When heated to decomposition, toxic fumes of nitrogen oxides are emitted. May ignite other combustible materials (wood, paper, oil, etc.). Mixture with fuels may explode. Container may explode in heat of fire. Vapor explosion and poison hazard may occur indoors, outdoors or in sewers. Decomposes in water, forming nitric acid and nitric oxide. Avoid moisture and physical damage to storage container.

Incompatible with combustible matter, chlorinated hydrocarbons, ammonia, carbon disulfide. Reacts with alkalies to form nitrates and nitrites. Violent reaction with cyclohexane, fluorine, formaldehyde, alcohols, nitrobenzene, petroleum, and toluene. (EPA, 1998)

U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 124 (Nitrogen dioxide)

· Substance does not burn but will support combustion.

· Vapors from liquefied gas are initially heavier than air and spread along ground.

· These are strong oxidizers and will react vigorously or explosively with many materials including fuels.

· May ignite combustibles (wood, paper, oil, clothing, etc.).

· Some will react violently with air, moist air and/or water.

· Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices.

· Containers may explode when heated.

· Ruptured cylinders may rocket.

Not combustible but enhances combustion of other substances.

10.1.7 Hazards Summary

Silo-filler's disease is an acute condition caused by NO2. [Sullivan, p. 818] This often fatal disease occurs when farmers enter a silo 1 to 10 days after fresh silage has been stored. Like phosgene and ozone, it is less soluble that other irritant inhalants and more likely to cause severe pulmonary edema without the signs of severe upper respiratory injury. (See Comments for phosgene.) [LaDou, p. 563] NO2 poisoning may also cause methemoglobinemia. [Ford, p. 685] Blasting and diesel powered machines generate NO2 at levels of 0.02-0.8 ppm during tunnel construction. . . . Cumulative exposure to nitrogen dioxide showed the strongest association with a decrease in FEV1 in both non-smokers, and ever smokers. Two studies of miners exposed to nitrogen dioxide at 0.02-0.1 ppm found no effect on lung function. [Reference #2] Heavier than air--accumulates in enclosed spaces; TLV Basis = lower respiratory tract irritant; [ACGIH] Nitrogen dioxide is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.
Sullivan - Sullivan JB, Krieger GR (eds). Clinical Environmental Health and Toxic Exposures. Philadelphia: Lippincott Williams & Wilkins, 2001., p. 818
LaDou - LaDou J, Harrison R (eds). Current Occupational & Environmental Medicine, 5th Ed. New York: McGraw-Hill, 2014., p. 563
Ford - Ford MD, Delaney KA, Ling LJ, Erickson T (eds). Clinical Toxicology. Philadelphia: W.B. Saunders, 2001., p. 685
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.

10.1.8 Fire Potential

It is noncombustible but it will accelerate the burning of combustible materials.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353

10.1.9 Skin, Eye, and Respiratory Irritations

Irritating to skin, eyes, and respiratory system. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110

10.1.10 EPA Hazardous Waste Number

P078; An acute hazardous waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate.

10.2 Safety and Hazard Properties

10.2.1 Acute Exposure Guideline Levels (AEGLs)

10.2.1.1 AEGLs Table
AEGLs
AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: ppm)
10 min
0.50
30 min
0.50
60 min
0.50
4 hr
0.50
8 hr
0.50
AEGLs
AEGL 2: Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape (Unit: ppm)
10 min
20
30 min
15
60 min
12
4 hr
8.2
8 hr
6.7
AEGLs
AEGL 3: Life-threatening health effects or death (Unit: ppm)
10 min
34
30 min
25
60 min
20
4 hr
14
8 hr
11
10.2.1.2 AEGLs Notes
AEGLs Status: Final

10.2.2 Flammable Limits

Flammability
Noncombustible Liquid/Gas, but will accelerate the burning of combustible materials.

10.2.3 Lower Explosive Limit (LEL)

Does not burn. (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.

10.2.4 Upper Explosive Limit (UEL)

Does not burn. (EPA, 1998)
U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.

10.2.5 Critical Temperature & Pressure

Critical temperature: 157.8 °C; critical pressure: 99.96 atm
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1142

10.2.6 Physical Dangers

The gas is heavier than air.

10.2.7 OSHA Standards

Permissible Exposure Limit: Table Z-1 Ceiling value: 5 ppm (9 mg/cu m).
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov
Vacated 1989 OSHA PEL STEL 1 ppm (1.8 mg/cu m) is still enforced in some states.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997., p. 368

10.2.8 NIOSH Recommendations

Recommended Exposure Limit: 15 Min Short-Term Exposure Limit: 1 ppm (1.8 mg/cu m).
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

10.3 First Aid Measures

Inhalation First Aid
Fresh air, rest. Half-upright position. Administration of oxygen may be needed. Refer immediately for medical attention.
Skin First Aid
First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Refer immediately for medical attention.
Eye First Aid
Rinse with plenty of water for several minutes (remove contact lenses if easily possible). Refer immediately for medical attention.
Ingestion First Aid
Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention.

10.3.1 First Aid

Warning: Effects may be delayed for hours to days. Caution is advised.

Signs and Symptoms of Acute Nitrogen Dioxide Exposure: Acute exposure to nitrogen dioxide may be severe and result in a weak, rapid pulse; cyanosis (blue tint to the skin and mucous membranes); and circulatory collapse. Cough, dyspnea (shortness of breath), bronchitis, pneumonitis, and pulmonary edema may occur following inhalation exposure. Gastrointestinal symptoms include nausea and abdominal pain. Fatigue, lethargy, restlessness, fever, anxiety, headache, mental confusion, and loss of consciousness may also occur. Contact with the skin and mucous membranes may result in severe irritation and burns. When liquid nitrogen dioxide contacts the skin, frostbite will result.

Emergency Life-Support Procedures: Acute exposure to nitrogen dioxide may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:

1. Move victims to fresh air. Emergency personnel should avoid self-exposure to nitrogen dioxide.

2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

4. Transport to a health care facility.

Dermal/Eye Exposure:

1. Remove victims from exposure. Emergency personnel should avoid self- exposure to nitrogen dioxide.

2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

3. Remove contaminated clothing as soon as possible.

4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.

5. Wash exposed skin areas with soap and water for at least 15 minutes.

6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

7. Transport to a health care facility.

Ingestion Exposure:

1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

2. DO NOT induce vomiting or attempt to neutralize!

3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

4. Activated charcoal is of no value.

5. Give the victims water or milk: children up to 1 year old, 125 mL (4 oz or 1/2 cup); children 1 to 12 years old, 200 mL (6 oz or 3/4 cup); adults, 250 mL (8 oz or 1 cup). Water or milk should be given only if victims are conscious and alert.

6. Transport to a health care facility. (EPA, 1998)

U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 124 (Nitrogen dioxide)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingestedor inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuouscompressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Clothing frozen to the skin should be thawed before being removed.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(See general first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

10.4 Fire Fighting

Move container from fire area if you can do so without risk. Stay away from ends of tanks. Spray cooling water on containers that are exposed to flames until well after fire is out.

Extinguish with dry chemical, carbon dioxide, water spray, fog, or foam. For massive fire in cargo area, use unmanned hose holder or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (EPA, 1998)

U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
In case of fire in the surroundings, use appropriate extinguishing media. In case of fire: keep cylinder cool by spraying with water.

10.4.1 Fire Fighting Procedures

Nitrogen dioxide is non-flammable but supports combustion. Wearing proper equipment, shut off flow of gas. Use water spray to keep containers cool and to direct escaping gas away from those effecting shut off. Do not extinguish the fire unless the flow of gas can be stopped and any remaining gas is out of the line. Specially trained personnel may use fog lines to cool exposures and let the fire burn itself out. Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position. If cylinders are exposed to excessive heat from fire or flame contact, withdraw immediately to a secure location ... The only respirators recommended for fire fighting are self-contained breathing apparatuses that have full facepieces and are operated in a pressure-demand or other positive-pressure mode.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 5th Edition Volume 1: A-H,Volume 2: I-Z. William Andrew, Norwich, NY 2008, p. 217
Extinguish surrounding fire using suitable agent. Use water spray to keep fire-exposed containers cool. Approach fire from upwind to avod hazardous vapors. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110
Wear special protective clothing and positive pressure self-contained breating apparatus. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110
If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use foam, dry chemical, or carbon dioxide.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353
Turn leaking cylinder with the leak up to prevent escape of gas in liquid state.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on Nitrogen dioxide (May 2003). Available from, as of May 20, 2010: https://www.inchem.org/pages/icsc.html

10.4.2 Firefighting Hazards

Cylinders and ton containers may not be equipped with a safety relief device. Prolonged exposure of the containers to fire or heat may result in their violent rupturing and rocketing.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353

10.5 Accidental Release Measures

Public Safety: ERG 2024, Guide 124 (Nitrogen dioxide)

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).

· Ventilate closed spaces before entering, but only if properly trained and equipped.

Spill or Leak: ERG 2024, Guide 124 (Nitrogen dioxide)

· Do not touch or walk through spilled material.

· Keep combustibles (wood, paper, oil, etc.) away from spilled material.

· Stop leak if you can do it without risk.

· Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.

· Do not direct water at spill or source of leak.

· If possible, turn leaking containers so that gas escapes rather than liquid.

· Prevent entry into waterways, sewers, basements or confined areas.

· Isolate area until gas has dispersed.

· Ventilate the area.

10.5.1 Isolation and Evacuation

Excerpt from ERG Guide 124 [Gases - Toxic and/or Corrosive - Oxidizing]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1067 datasheet.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Evacuation: ERG 2024, Guide 124 (Nitrogen dioxide)

Immediate precautionary measure

· Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

Spill

· See Table 1 - Initial Isolation and Protective Action Distances.

Fire

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Isolation

Small spill:

- ISOLATE in all directions: 30 m (100 ft)

Large spill:

- ISOLATE in all directions: 400 m (1250 ft)

Protection

Small spill:

- PROTECT people from downwind during DAY time: 0.1 km (0.1 mi)

- PROTECT people from downwind during NIGHT time: 0.4 km (0.3 mi)

Large spill:

- PROTECT people from downwind during DAY time: 1.4 km (0.9 mi)

- PROTECT people from downwind during NIGHT time: 3.3 km (2.1 mi)

10.5.2 Spillage Disposal

Evacuate danger area! Consult an expert! Personal protection: gas-tight chemical protection suit including self-contained breathing apparatus. Ventilation. Do NOT absorb in saw-dust or other combustible absorbents. Remove vapour with fine water spray. Neutralize used water with chalk or soda.

10.5.3 Cleanup Methods

Spill handling: keep unnecessary people away. Isolate hazard arae and deny entry. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering them. Evacuate area endangered by gas. For water spills, neutralize with agricultural lime (slaked lime), crushed limestone, or sodium bicarbonate. For an air spill, apply water spray or mist to knock down vapors. Vapor knockdown water is corrosive or toxic and should be diked for containment. Keep combustibles (wood, paper, oil, etc.) away from spilled material. Stop leak if you can do so without risk. Use water spray to reduce vapor but do not put water on leak or spill area. Isolate area until gas has dispersed. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations ... Initial isolation and protective action distances: Distances shown are likely to be affected during the first 30 min after materials are spilled and could increase with time. If more than one tank car, cargo tank, portable tank, or large cylinder involved in the incident is leaking, the protective action distance may need to be increased ... Small spills (from a small package or a small leak from a large package): first isolate in all directions 200 ft, then protect persons downwind, 0.1 mile (day), 0.3 mile (night). Large spills (from a large package or from many small packages): first isolate in all directions 500 ft, then protect persons downwind 0.1 mile (day), 2.5 miles (night).
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 5th Edition Volume 1: A-H,Volume 2: I-Z. William Andrew, Norwich, NY 2008, p. 1870
Releases may require isolation or evacuation. Stop or control the leak if this can be done without undue risk. Use water spray to disperse vapors and protect personnel. Approach release from upwind. Runnoff of less volatile nitrogen oxides may contain highly corrosive nitric acid. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110
Ventilate area of spill or leak to disperse gas. If in the liquid form, allow to vaporize. If in the gaseous form, stop flow of gas. If source of leak is a cylinder and the leak cannot be stopped in place, remove the leaking cylinder to a safe place in the open air and repair the leak or allow the cylinder to empty.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 3
Environmental considerations - land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed poylurethane , or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushed limestone (CaCO3)or sodium bicarbonate (NaHCO3).
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353
For more Cleanup Methods (Complete) data for Nitrogen dioxide (6 total), please visit the HSDB record page.

10.5.4 Disposal Methods

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P078, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
40 CFR 240-280, 300-306, 702-799 (7/1/2008)
Nitrogen dioxide is a poor candidate for incineration.
USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-9 (1981) EPA 68-03-3025

10.5.5 Preventive Measures

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
If material not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353
Personnel protection: Avoid breathing vapors. Keep upwind ... Avoid bodily contact with the material ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353
Evacuation: If material leaking (not on fire) consider evacuation of one-half (1/2) mile radius based on amount of material spilled, location and weather conditions.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 353
For more Preventive Measures (Complete) data for Nitrogen dioxide (9 total), please visit the HSDB record page.

10.6 Handling and Storage

10.6.1 Nonfire Spill Response

Excerpt from ERG Guide 124 [Gases - Toxic and/or Corrosive - Oxidizing]:

Do not touch or walk through spilled material. Keep combustibles (wood, paper, oil, etc.) away from spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Isolate area until gas has dispersed. Ventilate the area. (ERG, 2024)

10.6.2 Safe Storage

Ventilation along the floor. Separated from combustible substances and reducing agents.

10.6.3 Storage Conditions

Corrosive to steel when wet, but may be stored in steel cylinders when moisture content is 0.1% or less.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1143
Protect containers from physical damage. Store separately from combustible, organic, and readily oxidizable materials. Transfer facilities should be outdoors.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 5th Edition Volume 1: A-H,Volume 2: I-Z. William Andrew, Norwich, NY 2008, p. 1870
Store in a cool, dry, well-ventilated location. Separate from oxidizable materials. Outside or detached storage is preferred. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110
Ventilation along the floor.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on Nitrogen dioxide (May 2003). Available from, as of May 20, 2010: https://www.inchem.org/pages/icsc.html

10.7 Exposure Control and Personal Protection

Protective Clothing: ERG 2024, Guide 124 (Nitrogen dioxide)

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

Exposure Summary
TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].
Maximum Allowable Concentration (MAK)
0.5 [ppm]

10.7.2 Permissible Exposure Limit (PEL)

PEL-C (Ceiling)
5 ppm (9 mg/m³)
C 5 ppm (9 mg/m³) See Appendix G

10.7.3 Immediately Dangerous to Life or Health (IDLH)

13 ppm (NIOSH, 2024)

13.0 [ppm]

Excerpts from Documentation for IDLHs: It has been reported that 10 to 20 ppm has been mildly irritating [Patty 1963]. Exposure to 150 ppm or more (no time period given) has been reported to cause death from pulmonary edema [NRC 1979]. It has been predicted that 50% lethality would occur following exposure to 174 ppm for 1 hour [Book 1982].

20 ppm
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

13 ppm

See: 2017-202

10.7.4 Threshold Limit Values (TLV)

0.2 [ppm]
8 hr Time Weighted Avg (TWA): 3 ppm; 15 min Short Term Exposure Limit (STEL): 5 ppm.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2010, p. 45
A4; Not classifiable as a human carcinogen.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2010, p. 45
0.2 ppm as TWA; A4 (not classifiable as a human carcinogen).
TLV-TWA (Time Weighted Average)
0.2 ppm [2011]

10.7.5 Occupational Exposure Limits (OEL)

EU-OEL
0.96 mg/m
MAK (Maximale Arbeitsplatz Konzentration)
0.95 mg/m

10.7.6 Emergency Response Planning Guidelines

Emergency Response: ERG 2024, Guide 124 (Nitrogen dioxide)

CAUTION: These materials do not burn but will support combustion. Some will react violently with water.

Small Fire

· Contain fire and let burn. If fire must be fought, water spray or fog is recommended.

· Water only; no dry chemical, CO2 or Halon®.

· Do not get water inside containers.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Damaged cylinders should be handled only by specialists.

Fire Involving Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Do not direct water at source of leak or safety devices; icing may occur.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

ERPG-1: 1 ppm - one hour exposure limit: 1 = mild transient health effects or objectionable odor [AIHA]

ERPG-2: 15 ppm - one hour exposure limit: 2 = impaired ability to take protective action [AIHA]

ERPG-3: 30 ppm - one hour exposure limit: 3 = life threatening health effects [AIHA]

10.7.7 Other Standards Regulations and Guidelines

Emergency Response Planning Guidlines (ERPGs) for nitrogen dioxide:
ERPGs for Nitrogen Dioxide
The ERPG-1: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient adverse health effects or without perceiving a clearly defined objectionable odor.
Maximum Airborne Concentration
1 ppm
ERPGs for Nitrogen Dioxide
The ERPG-2: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action.
Maximum Airborne Concentration
15 ppm
ERPGs for Nitrogen Dioxide
The ERPG-3: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects.
Maximum Airborne Concentration
30 ppm
American Industrial Hygiene Association; Emergency Response Planning Guidelines & Workplace Enviromental Exposure Levels. Fairfax, VA 2009, p. 26

10.7.8 Inhalation Risk

A harmful concentration of this gas in the air will be reached very quickly on loss of containment.

10.7.9 Effects of Short Term Exposure

The substance is corrosive to the eyes, skin and respiratory tract. Exposure at high concentrations could cause asphyxiation due to swelling in the throat. Inhalation of the gas or vapour may cause lung oedema. Exposure far above the OEL could cause death. The effects may be delayed. Severe effects may occur following a prolonged symptom-free period. Medical observation is indicated.

10.7.10 Effects of Long Term Exposure

The substance may have effects on the lungs. This may result in impaired functions and decreased resistance to infection.

10.7.11 Personal Protective Equipment (PPE)

Excerpt from NIOSH Pocket Guide for Nitrogen dioxide:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:

• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.

• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

Wear appropriate personal protective clothing to prevent skin contact.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Wear appropriate eye protection to prevent eye contact.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Eyewash fountains should be provided in areas where there is any possbility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.]
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
For more Personal Protective Equipment (PPE) (Complete) data for Nitrogen dioxide (7 total), please visit the HSDB record page.

(See personal protection and sanitation codes)

Skin: Prevent skin contact - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: Prevent eye contact - Wear appropriate eye protection to prevent eye contact.

Wash skin: When contaminated

Remove: When wet or contaminated

Change: No recommendation

Provide: Eyewash, Quick drench

10.7.12 Respirator Recommendations

NIOSH

Up to 20 ppm:

(APF = 25) Any supplied-air respirator operated in a continuous-flow mode

(APF = 50) Any self-contained breathing apparatus with a full facepiece

(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:

(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

10.7.13 Preventions

Fire Prevention
NO contact with combustible substances.
Exposure Prevention
AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!
Inhalation Prevention
Use breathing protection, closed system or ventilation.
Skin Prevention
Protective gloves. Protective clothing.
Eye Prevention
Wear safety goggles or eye protection in combination with breathing protection.
Ingestion Prevention
Do not eat, drink, or smoke during work.

10.8 Stability and Reactivity

10.8.1 Air and Water Reactions

Combines with oxygen to form nitrogen dioxide, a brown gas that is deadly poisonous [Merck 11th ed. (1989]. Decomposes in water to form nitric acid and nitric oxide, reacts with alkalis to form nitrate and nitrites [Merck 11th ed. 1989]. The liquid nitrogen oxide is very sensitive to detonation, in the presence of water.

10.8.2 Reactive Group

Oxidizing Agents, Strong

10.8.3 Reactivity Alerts

Strong Oxidizing Agent

Water-Reactive

Air-Reactive

10.8.4 Reactivity Profile

Nitrogen Dioxide (nitrogen peroxide) is a strong oxidizing agent. Powdered aluminum burns in the vapor of carbon disulfide, sulfur dioxide, sulfur dichloride, nitrous oxide, nitric oxide, or nitrogen peroxide [Mellor 5:209-212. 1946-47]. Boron trichloride reacts energetically with nitrogen peroxide, phosphine, or fat and grease [Mellor 5:132. 1946-47]. Nitrogen peroxide and acetic anhydride reacted to form tetranitromethane, but resulted in an explosion [Van Dolah 1967]. Nitrogen peroxide forms explosive mixtures with incompletely halogenated hydrocarbons [Chem. Eng. News 42(47):53. 1964]. During an experiment to produce lactic acid by oxidizing propylene with nitrogen peroxide, a violent explosion occurred. These mixtures (olefins and nitrogen peroxide) form extremely unstable nitrosates or nitrosites [Comp. Rend. 116:756. 1893]. Contact of very cold liquefied gas with water may result in vigorous or violent boiling of the product and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container [Handling Chemicals Safely 1980]. Corrosive to steel when wet, but may be stored in steel cylinders when moisture content is 0.1% or less.

10.8.5 Hazardous Reactivities and Incompatibilities

A strong oxidizer. Reacts violently with combustible matter, chlorinated hydrocarbons, ammonia, carbon disulfide, reducing materials. Reacts with water, forming nitric acid and nitric oxide. Attacks steel in the presence of moisture.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 5th Edition Volume 1: A-H,Volume 2: I-Z. William Andrew, Norwich, NY 2008, p. 1868
The oxides of nitrogen react with a broad range of materials, and decomposition may occur under certain conditions. /Nitrogen oxides/
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-110
Violent reaction with cyclohexane, /fluorine/, formaldehyde, alcohols, nitrobenzene, petroleum, toluene.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2678
Combustible material, water, chlorinated hydrocarbons, carbon disulfide, ammonia [Note: Reacts with water to form nitric acid].
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Interaction of nitrates when heated with amidosulfates (sulfamates) may become explosively violent owing to liberation of dinitrogen oxide and steam.
Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990, p. 1339

10.9 Transport Information

10.9.1 DOT Emergency Guidelines

If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY.

Table: Table of Initial Isolation and Protective Action Distances for Nitrogen dioxide

Small Spills (from a small package or small leak from a large package)
First ISOLATE in all Directions 30 meters (100 feet)
Then PROTECT persons Downwind during DAY: 0.1 kilometers (0.1 miles)
Then PROTECT persons Downwind during NIGHT: 0.4 kilometers (0.2 miles)
Small Spills (from a small package or small leak from a large package)
Large Spills (from a large package or from many small packages)
Small Spills (from a small package or small leak from a large package)
First ISOLATE in all Directions 400 meters (1250 feet)
Then PROTECT persons Downwind during DAY: 1.1 kilometers (0.7 miles)
Then PROTECT persons Downwind during NIGHT: 3.0 kilometers (1.9 miles)

U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008301
/GUIDE 124: GASES - TOXIC AND/OR CORROSIVE - OXIDIZING/ Health: TOXIC; may be fatal if inhaled or absorbed through skin. Fire will produce irritating, corrosive and/or toxic gases. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Runoff from fire control may cause pollution.
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/GUIDE 124: GASES - TOXIC AND/OR CORROSIVE - OXIDIZING/ Fire or Explosion: Substance does not burn but will support combustion. Vapors from liquefied gas are initially heavier than air and spread along ground. These are strong oxidizers and will react vigorously or explosively with many materials including fuels. May ignite combustibles (wood, paper, oil, clothing, etc.). Some will react violently with air, moist air and/or water. Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/GUIDE 124: GASES - TOXIC AND/OR CORROSIVE - OXIDIZING/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering.
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
For more DOT Emergency Guidelines (Complete) data for Nitrogen dioxide (9 total), please visit the HSDB record page.

10.9.2 DOT ID and Guide

10.9.3 Shipping Name / Number DOT/UN/NA/IMO

UN 1067; Nitrogen dioxide
IMO 2.3; Nitrogen dioxide

10.9.4 Standard Transportation Number

49 203 40; Nitrogen dioxide, liquefied

10.9.5 Shipment Methods and Regulations

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
49 CFR 171.2; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of February 15, 2006: https://www.ecfr.gov
The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.
International Air Transport Association. Dangerous Goods Regulations. 47th Edition. Montreal, Quebec Canada. 2006., p. 44
The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
International Maritime Organization. International Maritime Dangerous Goods Code. London, UK. 2004., p. 182, 226

10.9.6 DOT Label

Poison Gas Oxidizer Corrosive

10.9.7 EC Classification

Symbol: O, T+; R: 8-26-34; S: (1/2)-9-26-28-36/37/39-45; Note: 5

10.9.8 UN Classification

UN Hazard Class: 2.3; UN Subsidiary Risks: 5.1 and 8

10.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Nitrogen oxide (NO2)
California Safe Cosmetics Program (CSCP) Reportable Ingredient

Hazard Traits - Respiratory Toxicity

Authoritative List - OEHHA RELs

Report - if used as a fragrance or flavor ingredient

REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
Nitrogen dioxide (dinitrogen tetroxide): HSNO Approval: HSR001380 Approved with controls

10.10.1 Atmospheric Standards

National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb, which is 1 part in 1,000,000,000), annual average concentration, measured in the ambient air as nitrogen dioxide. (b) The level of the national primary 1-hour ambient air quality standard for oxides of nitrogen is 100 ppb, 1-hour average concentration, measured in the ambient air as nitrogen dioxide. (c) The level of the national secondary ambient air quality standard for nitrogen dioxide is 0.053 parts per million (100 micrograms per cubic meter), annual arithmetic mean concentration.
40 CFR 50.11 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov

10.10.2 State Drinking Water Guidelines

(FL) FLORIDA 7,000 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

10.10.3 Clean Water Act Requirements

Nitrogen dioxide is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.
40 CFR 116.4 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov

10.10.4 CERCLA Reportable Quantities

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
40 CFR 302.4 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov
Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Nitrogen dioxide is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100 lbs.
40 CFR 355 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov

10.10.5 RCRA Requirements

P078; As stipulated in 40 CFR 261.33, when nitrogen dixoide, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to federal and/or state hazardous waste regulations. Also defined as a hazardous waste is any container or inner liner used to hold this waste or any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5(e)).
40 CFR 261.33 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of June 2, 2010: https://www.ecfr.gov

10.11 Other Safety Information

10.11.1 Special Reports

WHO; Environmental Health Criteria 188: Nitrogen dioxide (1997). EHC are designed for scientists and administrators responsible for the establishment of safety standards and regulations and provide basic scientific risk evaluations of a wide range of chemicals and groups of chemicals.

11 Toxicity

11.1 Toxicological Information

11.1.1 Toxicity Summary

IDENTIFICATION: Nitric oxide is a colorless, odorless gas that is only slightly soluble in water. The main sources of nitrogen oxides (including nitric oxide) emissions are combustion processes. Fossil fuel power stations, motor vehicles and domestic combustion appliances emit nitrogen oxides, mostly in the form of nitric oxide. Nitric oxide can be present at significant concentrations in ambient air and in indoor air. HUMAN EXPOSURE: Human exposure to nitrogen oxides varies from indoors to outdoors, from cities to the countryside, and with the time of day and season. Nitric oxide is readily oxidized to nitrogen dioxide and peroxidation then occurs. Because of the concurrent exposure to some nitrogen dioxide in nitric oxide exposures, it is difficult to discriminate nitric oxide effects from nitrogen dioxide. Nitric oxide functions as an intracellular second messenger modulating a wide variety of essential enzymes, and it inhibits its own production (e.g., negative feedback). Nitric oxide activates guanylate cyclase which in turn increases intracellular cGMP levels. Nitric oxide is acknowledged as an important endogenous second messenger within several organ systems. At certain levels, inhaled nitric oxide concentrations can cause vasodilation in the pulmonary circulation without affecting the systemic circulation. The lowest effective concentration is not established. Information on pulmonary function and lung host defenses consequent to nitric oxide exposure are too limited for any conclusions to be drawn. Relatively high concentrations have been used in clinical applications for brief periods without reported adverse effects. ANIMAL STUDIES: The toxicological database for nitric oxide is small, relative to nitrogen dioxide. It is often difficult to obtain pure nitric oxide in air without some contamination with nitrogen dioxide. Endogenous nitric oxide synthesis occurs by nitric oxide formation from physiological substrate in cells of many of the organ systems such as nerve tissue, blood vessels and the immune system. Nitric oxide may be more potent than nitrogen dioxide in introducing certain changes in lung morphology. In a study examining the effects of nitric oxide on bacterial defenses, there were no statistically significant effects for either sex at any of the time points studied. In vitro data indicate that nitric oxide stimulates guanylate cyclase and leads to smooth muscle relaxation and vasodilation and functional effects on the nervous system. These effects are probably responsible for vasodilation in the pulmonary circulation and an acute bronchodilator effect of inhaled nitric oxide. Nitric oxide has an affinity for heme-bound iron which is two times higher than that of carbon monoxide. This affinity leads to the formation of methemoglobin and the stimulation of guanylate cyclase. Furthermore, nitric oxide reacts with thiol-associated iron in enzymes and eventually displaces the iron. This is a possible mechanism for the cytotoxic effects of nitric oxide. Nitric oxide can deaminate DNA, evoke DNA chain breaks, and inhibit DNA polymerase and ribonucleotide reductase. It might be antimitogenic and inhibit T cell proliferation in rat spleen cells.
World Health Organization/International Programme on Chemical Safety. Environmental Health Criteria 188. Nitrogen oxides. pp. 1-18, 270-276, 331 (1997)

11.1.2 EPA IRIS Information

Toxicity Summary
EPA IRIS Summary PDF (Update: Sep-01-1994 )

11.1.3 RAIS Toxicity Values

Inhalation Acute Reference Concentration (RfCa) (mg/m^3)
0.47
Inhalation Acute Reference Concentration Reference
CALEPA

11.1.4 NIOSH Toxicity Data

11.1.5 Evidence for Carcinogenicity

A4; Not classifiable as a human carcinogen.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2010, p. 45

11.1.6 Exposure Routes

The substance can be absorbed into the body by inhalation.
inhalation, ingestion, skin and/or eye contact

11.1.7 Symptoms

Inhalation Exposure
Cough. Sore throat. Shortness of breath. Dizziness. Headache. Burning sensation. Laboured breathing. Nausea. Symptoms may be delayed.
Skin Exposure
Redness. Burning sensation. Pain. Serious skin burns.
Eye Exposure
Redness. Pain. Severe burns.
Ingestion Exposure
Burns in mouth and throat.
irritation eyes, nose, throat; cough, mucoid frothy sputum, decreased pulmonary function, chronic bronchitis, dyspnea (breathing difficulty); chest pain; pulmonary edema, cyanosis, tachypnea, tachycardia

11.1.8 Target Organs

Eyes, respiratory system, cardiovascular system

11.1.9 Adverse Effects

Methemoglobinemia - The presence of increased methemoglobin in the blood; the compound is classified as secondary toxic effect

Chronic Bronchitis - Chronic bronchitis is persistent coughing and production of phlegm for at least 3 months out of the year for at least two successive years. (American Thoracic Society).

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

Fibrogenic - Inducing tissue injury and fibrosis (scarring).

ACGIH Carcinogen - Not Classifiable.

11.1.10 Toxicity Data

LC50 (rat) = 88 ppm/4H

11.1.11 Interactions

... C57BL/6 mice /were used to test/ whether exposure to NO2, followed by inhalation of the innocuous protein Ag, OVA, would result in allergen sensitization and the subsequent development of allergic airway disease. Following challenge with aerosolized OVA alone, mice previously exposed via inhalation to NO2 and OVA developed eosinophilic inflammation and mucus cell metaplasia in the lungs, as well as OVA-specific IgE and IgG1, and Th2-type cytokine responses. One hour of exposure to 10 parts per million NO2 increased bronchoalveolar lavage fluid levels of total protein, lactate dehydrogenase activity, and heat shock protein 70; promoted the activation of NF-kappaB by airway epithelial cells; and stimulated the subsequent allergic response to Ag challenge. Furthermore, features of allergic airway disease were not induced in allergen-challenged TLR2-/- and MyD88-/- mice exposed to NO2 and aerosolized OVA during sensitization. These findings offer a mechanism whereby allergen sensitization and asthma may result under conditions of high ambient or endogenous NO2 levels.
Bevelander M et al; J Immunol 179 (6): 3680-8 (2007)
Male rats were continuously exposed to nitrogen dioxide (14.4 ppm), sulfur dioxide (46.5 ppm) & to a mixture of both gases, & their effects on lung microsomal aryl hydrocarbon hydroxylase activity was determined. The preexposed animals were administered methylcholanthrene to investigate the exposure effect on enzyme inducibility & pattern of benzo(a)pyrene metabolites. Nitrogen dioxide significantly increased aryl hydrocarbon hydroxylase activity but no marked change was noted with sulfur dioxide. Induction of aryl hydrocarbon hydroxylase by methylcholanthrene was markedly inhibited by sulfur dioxide, only slightly by the mixture of nitrogen dioxide-sulfur dioxide but not by nitrogen dioxide alone.
HUSAIN MM, DEHNEN W; ARCH TOXICOL 40 (3): 207-10 (1978)
Seven adult male healthy volunteer subjects were exposed to 0.15 ppm each of ozone, sulfur dioxide, and nitrogen dioxide alone and in combination, with intermittant light exercise for 2 hr. Three of the 7 subjects developed cough during deep inspiration and 1 subject had chest pain during exposure to ozone alone. Among the various indices of pulmonary function tests, specific airway conductance was the most sensitive index to examine the changes produced by the exposure to ozone and other pollutants. Significant decrease of specific airway conductance in comparison with control measurements was observed in 6 of 7 subjects during exposure to ozone alone, and in all subjects durings exposures to the mixture of ozone and other pollutants. However, no significant enhancement of effect was observed in the mixture of ozone and other pollutants, although a slightly greater decrease of specific airway conductance was observed for the mixture of ozone and other pollutants than for ozone alone.
Kagawa J; Am Ind Hyg Assoc J 44 (1): 14-20 (1983)
Male CD-1 mice were exposed to a nominal concentration of 20 ppm of 15N-nitrogen dioxide (15NO2) for 6 hr/day for 4 days and for 2 hr on the day 5, and to 1 g morpholine/kg body wt by gavage daily for five consecutive days. N-Nitrosomorpholine (NMOR) was found in whole mice, stomach, skins with hair, and remains. The sum of individual tissue concentrations measured separately was 3421 ng/tissue, where the average skin weighed 4.3 g, the average stomach weighed 1.0 g and the average remains weighed 22.2 g. The average whole mouse weighed 27.7 g and contained a total of 3903 ng of NMOR. The concentration of NMOR was highest in the skin, next highest in the stomach, and lowest in the remains. However, the total quantity of NMOR per tissue, while highest in the skin (83%), was next highest in the remains (14.8%) and lowest in the stomach (2.2%). GC-MS analysis served to distinguish between the NMOR of 15NO2 origin and that of other origin. All of the NMOR in the whole mouse homogenates was identified as 15NMOR. In the stomach 73% was identified as 14NMOR, representing 1.6% of the total NMOR in the mouse, and 27% as 15NMOR, representing 0.6% of the total NMOR in the mouse. N-Nitrosamine formation in vivo is discussed as a possibly ongoing mammalian process.
Van Stee EW et al; Carcinogenesis 16 (1): 89-92 (1995)
The effects of simultaneous exposure to nitrogen dioxide and ozone on the levels of lipid peroxides and phospholipids in the lungs of 4 animal species were investigated. Male ICR mice, Golden hamsters, Wistar rats, and Hartley guinea pigs (6 animals/group) were exposed to a mixture of 0.4 ppm nitrogen dioxide (NO2) and 0.4 ppm ozone (O3) for 2 wk. Controls were exposed to clean air in a similar exposure chamber. It was shown that the concentrations of lipid peroxides (using as an index the concentrations of thiobarbituric acid (TBA) reactants) in lung tissue of guinea pigs and mice, exposed to the combined gases, were increased significantly when compared to the controls, (for guinea pigs: p< 0.01 at 7 days, p< 0.001 at 14 days; for mice: p< 0.05 at 7 days, p< 0.001 at 14 days). However, the lipid peroxide levels of hamsters and rats did not show any significant changes throughout the 2 wk of exposure. Significant increases in total phospholipids were observed in mice, rats and guinea pigs, but not in hamsters.
Sagai M et al; Toxicol 46: 251-65 (1987)

11.1.12 Antidote and Emergency Treatment

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Nitrogen Oxides (NOx) and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 289
Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Aggressive airway management may be needed. Encourage patient to take deep breaths. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Nitrogen Oxides (NOx) and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 289-90
Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation at the first signs of upper airway obstruction may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Administer 1% solution methylene blue if patient is symptomatic with severe hypoxia, cyanosis, and cardiac compromise not responding to oxygen. ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Nitrogen Oxides (NOx) and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 290
Emergency and supportive treatment. Observe closely for signs of upper-airway obstruction and intubate the trachea and assist ventilation if necessary. Administer humidified supplemental oxygen. observe symptomatic victims for a minimum of 24 hours after exposure and treat chemical pneumonia and noncardiogenic pulmonary edema if they occur. /Nitrogen oxides/
Olson, K.R. (Ed.); Poisoning & Drug Overdose. 5th ed. Lange Medical Books/McGraw-Hill. New York, N.Y. 2007., p. 282
For more Antidote and Emergency Treatment (Complete) data for Nitrogen dioxide (7 total), please visit the HSDB record page.

11.1.13 Medical Surveillance

Preplacement and periodic examinations should be concerned particularly with the skin, eyes, and with significant pulmonary and heart diseases. Periodic chest x-rays and pulmonary function tests may be useful. Smoking history should be known.
Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985., p. 660

11.1.14 Human Toxicity Excerpts

/HUMAN EXPOSURE STUDIES/ Twelve healthy, young non-smoking volunteers were exposed to 2 ppm of NO2/filtered air (four hours/day) for four successive days on separate occasions. Fiberoptic bronchoscopy was performed one hour after air and final NO2 exposures. Bronchial biopsy specimens were immunostained for NF-kappaB, TNF-alpha, eotaxin, Gro-alpha, GM-CSF, IL-5, -6, -8, -10, -13, and ICAM-1 and their expression was quantified using computerised image analysis. RESULTS: Expression of IL-5, IL-10, IL-13, and ICAM-1 increased following NO2 exposure. CONCLUSION: Upregulation of the Th2 cytokines suggests that repeated exposure to NO2 has the potential to exert a "pro-allergic" effect on the bronchial epithelium. Upregulation of ICAM-1 highlights an underlying mechanism for leucocyte influx, and could also explain the predisposition to respiratory tract viral infections following NO2 exposure since ICAM-1 is a major receptor for rhino and respiratory syncytial viruses.
Pathmanathan S et al; Occup Environ Med 60 (11): 892-6 (2003)
/HUMAN EXPOSURE STUDIES/ ... Twenty-one healthy volunteers were exposed on separate occasions to air and 0.6 and 1.5 ppm NO(2) for 3 hr with intermittent moderate exercise. Phlebotomy and bronchoscopy were performed 3.5 hr after each exposure, and recovered cells were challenged with respiratory viruses in vitro. Blood studies revealed a 4.1% NO(2) dose-related decrease in hematocrit (P = 0.003). Circulating total lymphocytes (P = 0.024) and T lymphocytes (P = 0.049) decreased with NO(2) exposure. Exposure to NO(2) increased the blood lymphocyte CD4(+)-to-CD8(+) ratio from 1.74 +/- 0.11 to 1.85 +/- 0.12 in males but decreased it from 1.88 +/- 0.19 to 1.78 +/- 0.19 in females (P < 0.001 for gender difference). Polymorphonuclear leukocytes in bronchial lavage increased with NO(2) exposure (P = 0.003). Bronchial epithelial cells obtained after exposure to 1.5 ppm NO(2) released 40% more lactate dehydrogenase after challenge with respiratory syncytial virus than with air exposure (P = 0.024). In healthy subjects, exposures to NO(2) at levels found indoors cause mild airway inflammation, effects on blood cells, and increased susceptibility of airway epithelial cells to injury from respiratory viruses.
Frampton MW et al; Am J Physiol 282 (1): 155-65 (2002)
/HUMAN EXPOSURE STUDIES/ ... To investigate the effect of exposure to nitrogen dioxide (NO2) on nasal airways resistance (NAR) and inflammatory mediators in nasal lavage fluid, eight subjects with a history of seasonal allergic rhinitis, who were tested out of season, were exposed in a randomized single-blind, crossover study to either air or 400 ppb NO2 for 6 hours. The changes in NAR and eosinophil cationic protein (ECP), mast cell tryptase (MCT), neutrophil myeloperoxidase (MPO), and interleukin-8 (IL-8) in nasal lavage fluid before and after exposure were evaluated. Another group of eight subjects with a history of seasonal allergic rhinitis were also randomized to exposure to air or 400 ppb NO2 for 6 hours and then challenged with allergen, before evaluation for changes in NAR and changes in ECP, MCT, MPO, and IL-8 in nasal lavage fluid. RESULTS: Exposure to air or NO2 did not alter either NAR or the levels of ECP, MCT, MPO, or IL-8 in nasal lavage fluid. Allergen challenge after exposure to both air and NO2 significantly (p < 0.05) increased levels of MCT, but not MPO and IL-8 in the nasal lavage fluid. In addition, allergen challenge after exposure to NO2 but not air, significantly increased levels of only ECP in nasal lavage fluid (p < 0.05). CONCLUSIONS: These results suggest that acute exposure to NO2 at concentrations found at the curbside in heavy traffic during episodes of pollution, may "prime" eosinophils for subsequent activation by allergen in individuals with a history of seasonal allergic rhinitis.
Wang JH et al; J Allergy Clin Immunol 96 (5 Pt 1): 669-76 (1995)
/HUMAN EXPOSURE STUDIES/ ... Eighteen subjects with asthma and allergy to pollen were exposed at rest to either purified air or NO2 for 30 min followed 4 hr later by an allergen inhalation challenge. Responsiveness to histamine was measured the day after. Lung function during NO2 exposure and allergen challenge was measured by plethysmography and after exposure by a portable spirometer hourly. The order of exposure to NO2 and air was randomized and separated by at least 2 wk. The asthmatic reaction during the late phase was enhanced by NO2, and peak expiratory flow after allergen challenge was on average 6.6% lower (p = 0.02) after NO2 than after air exposure. The number of subjects having a late asthmatic reaction (fall in FEV1 > 15%) was seven after air and 10 after NO2 (NS). Peripheral blood samples were analyzed for differential cell counts before and after NO2/allergen and serum levels of eosinophil cationic protein (ECP). NO2 effect on lung function was neither associated with an increase in eosinophil numbers nor with ECP levels. NO2 did not affect lung function before allergen challenge, early asthmatic reaction, and allergen-induced increase in responsiveness to histamine. These results indicate that short exposure to an ambient level of NO2 followed several hours later by allergen inhalation enhances allergen-induced late asthmatic reaction.
Strand V et al; Am J Resp Crit Care Med 155 (3): 881-7 (1997)
For more Human Toxicity Excerpts (Complete) data for Nitrogen dioxide (56 total), please visit the HSDB record page.

11.1.15 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ Ozone (O(3)) and nitrogen dioxide (NO(2)) are highly reactive and toxic oxidant pollutants. The objective of this study is to compare chemokine, cytokine, and antioxidant changes elicited by acute exposures of O(3) and NO(2) in a genetically sensitive mouse. Eight-week-old C57Bl/6J mice were exposed to 1 or 2.5 ppm ozone or 15 or 30 ppm NO(2) for 4 or 24 hr. Changes in mRNA abundance in lung were assayed by slot blot and ribonuclease protection assay (RPA). Messages encoding metallothionein (Mt), heme oxygenase I (HO-I), and inducible nitric oxide synthase (iNOS) demonstrated increased message abundance after 4 and 24 hr of exposure to either O(3) or NO(2). Furthermore, increases in message abundance were of a similar magnitude for O(3) and NO(2). Messages encoding eotaxin, macrophage inflammatory protein (MIP)-1alpha, and MIP-2 were elevated after 4 and 24 hr of exposure to 1 ppm ozone. Interleukin-6 was elevated after 4 h of exposure to ozone. After 4 hr of 2.5 ppm ozone exposure, increased mRNAs of eotaxin, MIP-1alpha, MIP-2, Mt, HO-I, and iNOS were elevated to a higher magnitude than were detected after 1 ppm ozone. Monocyte chemoattractant protein (MCP-1) was elevated following 15 ppm NO(2) exposure. After 4 h of 30 ppm NO(2) exposure, messages encoding eotaxin, MIP-1alpha, MIP-2, and MCP-1 were elevated to levels similar to those detected after ozone exposure. /The/ results demonstrate a similar antioxidant and chemokine response during both O(3) and NO(2) exposure. Induction of these messages is associated with the duration and concentration of exposure. These studies suggest that these gases exert toxic action through a similar mechanism.
Johnston CJ et al; Inh Toxicol 12 (3): 187-203 (2000)
/LABORATORY ANIMALS: Acute Exposure/ Brief, high-level nitrogen dioxide (NO(2)) exposures are major hazards during fires and heat-generating explosions. To characterize the lung response to a brief high-level NO(2) exposure, we exposed two groups (n = 5) of 325-375 g, male, Sprague-Dawley rats to either 200 +/- 5 ppm (376 +/- 9 mg/m(3)) NO(2) or room air for 15 min. The rats were nose-only exposed in a multiport exposure chamber fitted with pressure transducers to monitor their respiration during exposure. One hour after exposure, we euthanized the rats, collected blood samples, lavaged the lungs with warm saline, and then excised them. One lung lobe was cooled to -196 degrees C and used for low-temperature electron paramagentic resonance (EPR) analysis. The remainder was homogenized and used for biochemical analyses. Inspired minute ventilation (V(i)) during exposure decreased 59% (p < 0.05). Calculated total inspired dose was 0.880 mg NO(2). In lung lavage, both total and alveolar macrophage cell counts declined (approximately 75%, p < 0.05), but epithelial cell count increased 8.5-fold. Lung weight increased 40% (p < 0.05) after exposure. In the blood, potassium and methemoglobin increased 45 and 18% (p < 0.05), respectively; glucose, lactate, and total hemoglobin were not altered significantly. EPR analysis of lung tissue revealed hemoglobin oxidation and carbon-centered radical formation. Vitamins E and C and uric acid were depleted, and lipid peroxidation measured by three different methods (TBARS, conjugated dienes, and fluorescent peroxidation end products) was elevated, but total protein, DNA, and lipid contents were unchanged. These observations combined demonstrate that a brief (15 min) high-level (200 ppm) NO(2) exposure of rats was sufficient to cause significant damage. However, comparison of the exposure dose normalized to rat body weight with previously reported sheep and estimated human values revealed significant differences. This raises a question about interspecies dosimetry and species-specific responses when animal data are extrapolated to humans and used for safety standard setting, particularly with high-level brief exposures.
Elsayed N et al; Toxicol Appl Pharmacol 184 (1): 1-10 (2002)
/LABORATORY ANIMALS: Acute Exposure/ ... Whether acute exposure to nitrogen dioxide (NO2) causes major inflammatory responses (inflammatory cell recruitment, edema and smooth muscle hyperresponsiveness) in guinea pig airways /was examined/. Anesthetised guinea pigs were exposed to 18 ppm NO2 or air for 4 hr through a tracheal cannula. Bronchoalveolar lavage was performed and airway microvascular permeability and in vitro bronchial smooth muscle responsiveness were measured. Exposure to NO2 induced a significant increase in eosinophils and neutrophils in bronchoalveolar lavage fluid, microvascular leakage in the trachea and main bronchi (but not in peripheral airways), and a significant in vitro hyperresponsiveness to acetylcholine, electrical field stimulation, and neurokinin A, but not to histamine. Thus, this study shows that in vivo exposure to high concentrations of NO2 induces major inflammatory responses in guinea pig airways that mimic acute bronchitis induced by exposure to irritant gases in man.
Papi A et al; Eur J Pharmacol 374 (2): 241-7 (1999)
/LABORATORY ANIMALS: Acute Exposure/ ... The effects of inhaled nitrogen dioxide (NO2) ..., on pulmonary sensory neuropeptides /was examined/. Guinea-pigs were exposed for 4 hr to 18 parts per million (ppm) NO2 or to air (n = 5 each). At the end of the exposure, they were killed with urethane and their lungs were fixed in 1% paraformaldehyde in phosphate-buffered saline. Cryostat sections were stained with antisera to an anatomical nerve marker, protein gene product (PGP) 9.5, and to calcitonin gene-related peptide (CGRP) and tachykinins, utilizing the avidin-biotinylated peroxidase method. In the noncartilaginous airways (diameter < 250 microns) of NO2-exposed animals, less tachykinin- and CGRP-immunoreactive nerve fibres were found compared with controls. No change was seen in the total nerve fiber distribution (PGP 9.5). It is concluded that the peptidergic nerves of guinea-pig peripheral airways are a sensitive indicator of exposure to nitrogen dioxide.
Lucchini RE et al; Eur Resp J 9 (9): 1847-51 (1996)
For more Non-Human Toxicity Excerpts (Complete) data for Nitrogen dioxide (57 total), please visit the HSDB record page.

11.1.16 Non-Human Toxicity Values

LC50 Rat (male) 174 ppm/30 min
NIOSH; Criteria Document: Nitric acid p.78 (1976) DHEW Pub. NIOSH 76-141
LC50 Rat inhalation 88 ppm/4 hr
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2678
LC50 Mouse inhalation 1000 ppm/10 min
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2678
LC50 Monkey (species not given) inhalation 123 mg/cu m/8 hr
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2678
For more Non-Human Toxicity Values (Complete) data for Nitrogen dioxide (6 total), please visit the HSDB record page.

11.1.17 TSCA Test Submissions

Mortality was evaluated in nine groups of Swiss albino mice (48/group) chronically exposed to nitrogen dioxide at a nominal concentration of 0.5ppm, 24hrs/day for 8 months in a dynamic air flow chamber and challenged with an average cloud concentration of 1 x 10(4) viable org/l of Klebsiella pneumonia in a bacterial infectivity chamber for 15 minutes (Infectivity Model). After three months of nitrogen dioxide exposure, the serum lactic acid dehydrogenase pattern changed from an anaerobic pattern to an aerobic pattern, which was a significant difference relative to the air-exposed controls. The mortality after bacterial challenge, was higher in treated mice relative to the controls, but the differences were not statistically significant.
Texas Tech University School of Medicine; Infectivity Model Verification Studies, Annual Report, (1981), EPA Document No. FYI-AX-0382-0172, Fiche No. OTS0000172-0

11.1.18 Populations at Special Risk

... asthmatics appear to be the most susceptible members of the population. Asthmatics are generally much more sensitive to inhaled bronchoconstrictors.
WHO; Environ Health Criteria 188: Nitrogen dioxide p.282 (1997)
Another potentially susceptible group includes patients with COPD. A major concern with COPD patients is the absence of an adequate pulmonary reserve, so that even a relatively small alteration in lung function in these individuals could potentially cause serious problems.
WHO; Environ Health Criteria 188: Nitrogen dioxide p.283 (1997)

11.2 Ecological Information

11.2.1 Ecotoxicity Excerpts

/AQUATIC SPECIES/ Nitrogen dioxide does not exist per se in water, since it reacts instantaneously with water to form nitric and nitrous acids.
U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) on Nitrogen dioxide (CAS #10102-44-0). Available from, as of May 12, 2010: https://www.epa.gov/iris/subst/index.html

11.2.2 Environmental Fate / Exposure Summary

Nitrogen dioxide is an ubiquitous product of combustion, occurring in exhaust from motor vehicles, emissions from the combustion of stationary fuel sources such as coal, oil or natural gas and various industrial sources. Atmospheric oxidation of nitric oxide (NO) may also lead to the formation of nitrogen dioxide. Natural sources, such as forest fires, atmospheric lightning discharges and the biogenic oxidation of nitrogen containing compounds in soils may also release quantities of nitrogen dioxide directly to the environment. Nitrogen dioxide's production and use as an intermediate in the manufacture of nitric acid and as an oxidizing agent may also lead to its release to the environment through various waste streams. If released to air, a vapor pressure of 900 mm Hg at 25 °C indicates nitrogen dioxide will exist solely as a gas in the ambient atmosphere. Gas-phase nitrogen dioxide is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals with an estimated atmospheric half-life of 35 hours. Nitrogen dioxide dissolves with water to form nitric acid, which is a major constituent of acid rain. Nitrogen dioxide compound is expected to undergo direct photolysis in the environment, ultimately leading to the production of ozone and smog conditions in the lower troposphere. If released to soil, this compound is expected to decompose to nitric acid in moist soil surfaces. Nitrogen dioxide is expected to volatilize from dry soil surfaces based upon its vapor pressure. If released into water, nitrogen dioxide is expected to decompose to nitric acid. Occupational exposure to nitrogen dioxide may occur through inhalation and dermal contact with this compound at workplaces where nitrogen dioxide is produced or used or where combustion processes are important. The general population may be exposed to nitrogen dioxide through the inhalation of ambient air and by smoking tobacco products. (SRC)

11.2.3 Natural Pollution Sources

Natural sources, such as forest fires, atmospheric lightning discharges and the biogenic oxidation of nitrogen containing compounds in soils(1) may release quantities of nitrogen dioxide directly to the environment(SRC).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)

11.2.4 Artificial Pollution Sources

Volatile organics and nitrogen oxides are emitted by transportation and industrial sources. Oxides of nitrogen are emitted in the combustion of fossil fuels. /Nitrogen oxides/
Sullivan TFP; Pollution Engineering p.24 (June 1987)
... RELEASED IN REACTION BETWEEN NITRIC ACID & ANY ORG MATERIAL; IN EXHAUST FROM METAL CLEANING ... FROM ELECTRIC ARC WELDING; IN ELECTROPLATING, ENGRAVING, & PHOTOGRAVURE OPERATIONS; IN DYNAMITE BLASTING ... IN DIESEL ENGINE EXHAUST; IN BURNING OF NITROCELLULOSE ... & IN COMBUSTION OF SOME SHOE POLISHES. /NITROGEN OXIDES/
Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. III-320
/NITROGEN DIOXIDE & NITROGEN TETROXIDE/ ... ARE ... EVOLVED WHEN NITRATED ORG CMPD BURN OR EXPLODE, OR WHEN ORG CMPD (AS GASOLINE) BURN @ HIGH TEMP IN AIR (AUTOMOBILE EXHAUST).
Thienes, C., and T.J. Haley. Clinical Toxicology. 5th ed. Philadelphia: Lea and Febiger, 1972., p. 189
Nitrogen dioxide is an ubiquitous product of combustion, occurring in exhaust from motor vehicles, emissions from the combustion of stationary fuel sources such as coal, oil or natural gas and various industrial sources(1,2). Atmospheric oxidation of nitric oxide (NO) may also lead to the formation of nitrogen dioxide(1). Nitrogen dioxide's production and use as an intermediate in the manufacture of nitric acid and as an oxidizing agent(3) may also lead to its release to the environment through various waste streams(SRC).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
(2) Wolff GT: Kirk-Othmer's Encycl Chem Technol1 Kroschwitz JI ed. NY,NY: John Wiley & Sons 1: 711-49 (1991)
(3) Lewis RJ; Hawley's Condensed Chemical Dictionary. 12th ed. NY,NY: Van Nostrand Reinhold Co., p. 828 (1993)

11.2.5 Environmental Fate

TERRESTRIAL FATE: Nitrogen dioxide is expected to decompose to nitric acid in moist soil surfaces(1). The potential for volatilization of nitrogen dioxide from dry soil surfaces may exist(SRC) based upon a vapor pressure of 900 mm Hg at 25 °C(2).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
(2) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation Washington,DC: Taylor and Francis (1989)
AQUATIC FATE: If released into water, nitrogen dioxide is expected to decompose(1) to nitric acid(SRC).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
ATMOSPHERIC FATE: Nitrogen dioxide, which has a vapor pressure of 900 mm Hg at 25 °C(1), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase nitrogen dioxide is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 35 hours(SRC) from its rate constant of 1.1X10-11 cu cm/molecule-sec at 25 °C(2). This compound is expected to undergo direct photolysis in the environment(SRC), ultimately leading to the production of ozone and smog conditions in the lower troposphere(3).
(1) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation Washington,DC: Taylor and Francis (1989)
(2) Grosjean D; Sci Total Environ 46: 41-59 (1985)
(3) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)

11.2.6 Environmental Abiotic Degradation

The rate constant for the vapor-phase reaction of nitrogen dioxide with photochemically-produced hydroxyl radicals has been measured as 1.1 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 35 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(SRC). This compound is expected to undergo direct photolysis in the environment(SRC), ultimately leading to the production of ozone and smog conditions in the lower troposphere(2). Nitrogen dioxide is expected to decompose under aqueous conditions(2).
(1) Grosjean D; Sci Total Environ 46: 41-59 (1985)
(2) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)

11.2.7 Volatilization from Water / Soil

If released into water, nitrogen dioxide is expected to decompose to nitric acid(1). This compound is also expected to decompose in moist soil surfaces(1). The potential for volatilization of nitrogen dioxide from dry soil surfaces may exist(SRC) based upon a vapor pressure of 900 mm Hg at 25 °C(2).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
(2) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation Washington,DC: Taylor and Francis (1989)

11.2.8 Effluent Concentrations

The global emissions of nitrogen dioxide and nitric oxide from various sources in tons/yr were reported as follows: hard coal, 3.9X10+6; lignite, 1.6X10+6; light fuel oil, 0.7X10+6; heavy fuel oil, 1.1X10+6; natural gas, 1.9X10+6; industrial sources, 1.2X10+6; automobiles, 4.3X10+6(1). The global emissions of nitrogen dioxide and nitric oxide in tons/yr from natural sources were reported as follows: 8.6X10+6, lightening; 50X10+6, soil emissions; 0.35X10+6, oceans(1). The concn of nitrogen dioxide and nitric oxide in tonnes/yr emitted from sources in major cities were reported as follows: Bangkok, Thailand 60,000; Bombay, India 56,000; Buenos Aries, Argentina 27,000; Cairo, Egypt 24,700; Calcutta, India 36,500; Delhi, India 73,000; Jakarta, Indonesia 20,500; Karachi, Pakistan 50,000; London, England 79,000; Los Angeles, CA 440,000; Manila, Philippines 119,000; Mexico City, Mexico 117,300; Moscow, Russia 210,000; New York City, NY 120,000; Rio de Janeiro, Brazil 63,000; San Paulo, Puerto Rico 245,000; Seoul, South Korea 270,000; Shanghai, China 127,000; Tokyo, Japan 52,700(1). The US emissions of nitrogen dioxide and nitric oxide in tons/yr were reported as follows: transportation sources, 7.9X10+6; stationary fuel sources, 11.1X10+6; industrial sources, 0.6X10+6; solid waste sources, 0.1X10+6; miscellaneous sources, 0.2X10+6(2). The emissions of nitrogen dioxide and nitric oxide from a wood burning stove were measured as 64-657 ppb(3).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
(2) Wolff GT: Kirk-Othmer's Encycl Chemical Technol. 4th ed., Kroschwitz JI ed. NY, NY: John Wiley & Sons 1: 711-49 (1991)
(3) Kleindienst TE et al; Environ Sci Technol 20: 493-501 (1986)
Unvented gas-fired space heaters emitted 0.4-1.46 ppm of nitrogen dioxide during steady-state operation(1). A study of operation of an unvented natural gas fireplace in a home in Boulder, CO resulted in nitrogen dioxide emissions of 0.09, 0.35, and 0.36 ppm at low, medium, and high fireplace settings, sampled in June, 1999(2).
(1) Traynor GW et al; JAPCA 35: 231-37 (1985)
(2) Dutton SJ et al; J Air Waste Manage Assoc 52: 1654-61 (2001)

11.2.9 Atmospheric Concentrations

IN TERMS OF AMT OF MATERIAL EMITTED ANNUALLY INTO AIR, FIVE MAJOR POLLUTANTS ACCOUNT FOR CLOSE TO 98% OF POLLUTION. ... NITROGEN OXIDES (6%). /NITROGEN OXIDES/
Doull, J., C.D. Klaassen, and M. D. Amdur (eds.). Casarett and Doull's Toxicology. 2nd ed. New York: Macmillan Publishing Co., 1980., p. 608
SOURCE DOMINATED: The avg concn of nitrogen dioxide in the Craeybeckx tunnel in Belgium was reported as 206 ug/cu m(1). The mean nitrogen dioxide concn around the Gatwick Airport, UK was reported as 2.3 ppm with a range of 1.4-2.6 ppm(2).
(1) De Fre R et al; Environ Health Per 4: 31-37 (1994)
(2) Tsani-Bazaca E et al; Environ Monit Assess 4: 361-77 (1984)
URBAN/SUBURBAN: Ambient levels of nitrogen dioxide in ug/cu m were reported for the following cities: Bangkok, Thailand less than 320; Bombay, India 70-85; Delhi, India 500; London, England 867 (max concn); Los Angeles, CA 526 (max concn); Mexico City, Mexico 301-714; Moscow, Russia 100- 150; New York City, NY 87 (annual mean), 160 (max daily concn); San Paulo, Brazil 600-1,500(1). The daily range of nitrogen dioxide concns in Agra, India were 5.5-41.9 ug/cu m (1987), 6.3-33.1 ug/cu m (1988) and 4.2-15.2 ug/cu m (1989)(1). The avg nitrogen dioxide concn in US cities from 1980-1989 was 0.026-0.030 ppm (populations of over 1,000,000 persons), 0.020-0.023 ppm (populations of over 500,000 persons), 0.019-0.020 ppm (populations of over 250,000 persons)(1). The avg concn of nitrogen dioxide and nitric oxide in Chinese cities were 43-56 ug/cu m from 1981-1990(1). The avg 1 hour concn of nitrogen dioxide from 1986-1989 was reported as 0.04-0.16 ppm, Long Beach, CA; 0.04-0.15 ppm, Denver, CO; 0.02-0.08 ppm Cleveland, OH; 0.02-0.06 ppm, Richmond, VA(1). The annual avg concn of nitrogen dioxide from 214 stations in CA, MN, NH, MA, NY and OK were 0.02-0.05 ppm, while the max 1 hour concns at these sites were 0.01-0.5 ppm(1). The avg monthly concn of nitrogen dioxide in Parma, Italy was 0-100 ug/cu m from 1989-1994(2). The avg monthly concn of nitrogen dioxide in Tokyo, Japan from 1991-1992 was reported as 60-110 ug/cu m(3). The avg concn of nitrogen dioxide in Mill Valley, CA was reported as 3.6 ppb with a range of 0-40.5 ppb and the avg concn at Riverside, CA was reported as 27.3 ppb with a range of 3.5-60.5 ppb(4). The avg concn of nitrogen dioxide at several areas of southern California was 6-162 ppb and max concns of 30-162 ppb(5). Nitrogen dioxide was detected at an avg concn of 87.3 ug/cu m and a range of 8-196 ug/cu m in cars located in Raleigh, NC in 1988(6). Nitrogen dioxide was detected in the air of London, England at an avg concn of 36 ppb and a range of 22-83 ppb during 1991-1992 monitoring(7).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)
(2) Rossi C et al; Chemosphere 30: 1829-45 (1995)
(3) Ando M et al; Atmos Environ 30: 695-702 (1996)
(4) Singh HB et al; Fate of Halogenated Compounds in the Atmosphere. USEPA-600/3-78-017 (1978)
(5) Hisham MWM, Grosjean D; Environ Sci Technol 25: 857-62 (1991)
(6) Chan CC et al; Environ Sci Technol 25: 964-72(1991)
(7) Brown JR et al; Sci Total Environ 177: 73-84 (1996)
URBAN/SUBURBAN: Nitrogen dioxide concentrations were reported in air samples collected in Upland CA (ppbV; date) as follows: 12, 10/22/06; 24, 10/23/06; 28, 10/24/06; 26, 10/28/06; 20, 9/12/07; 17, 9/18/07; 17, 9/26/08 (Fontana, CA); and 33, 10/25/07 (Fontana, CA(1). The annual average concentration of nitrogen dioxide in Toronto, Ontario, Canada was reported to range from 24-37 ppb, daily maximum of 40-110 ppb, and annual maximum of 90-200 ppb, as indicated by analysis of samples collected during 1989 10 1991(2). Mean outdoor nitrogen dioxide levels of 29 ug/cu m and 31 ug/cu m were reported in 200 samples from Erfurt and Hamburg, Germany, respectively, sampled between June 1995 and November 1996(3) The mean outdoor concentrations of nitrogen dioxide in 37 urban dwellings in Nagoya, Japan and 27 urban dwellings in Uppsala, Sweden were reported as 5.8 and 1.3 ug/cu m, respectively; sampling was conducted in February, 1998 and February through May 1998, respectively(4).
(1) Nishino N et al; Environ Sci Technol 42: 9203-9209 (2008)
(2) Campbell ME et al; Can J Public Health 86: 351-357 (1995)
(3) Cyrys J et al; Sci Total Environ 250: 51-62 (2000)
(4) Sakai K et al; Environ Res 94: 75-85 (2004)
For more Atmospheric Concentrations (Complete) data for Nitrogen dioxide (7 total), please visit the HSDB record page.

11.2.10 Other Environmental Concentrations

The National Research Council(1986) reported nitric oxide and nitrogen dioxide emissions of 100-600 ug/cigarette for mainstream smoke with values 4-10 times greater for sidestream smoke(1). According to the report, most of the initial smoke is in the form of nitric oxide, but once emitted the nitric oxide is oxidized to nitrogen dioxide(1).
(1) Graham JA et al; in Environmental Health Criteria 188, WHO: Geneva, Switzerland (1997)

11.2.11 Probable Routes of Human Exposure

IN STAINLESS STEEL FUMES, AN ETIOLOGICAL FACTOR COMMON TO ALL FIBROGENIC WELDING EXPOSURES IS TENTATIVELY PROPOSED TO BE NITROGEN DIOXIDE, A POTENTIAL EXPERIMENTAL IN VIVO FIBROGEN PRODUCED BY CERTAIN WELDING PROCESSES & UBIQUITOUS AT LOW CONCENTRATIONS IN THE WELDING ENVIRONMENT.
STERN RM ET AL; J APPL TOXICOL 3 (1): 18-30 (1983)
NIOSH (NOES Survey 1981-1983) has statistically estimated that 18,737 workers (1,773 of these are female) are potentially exposed to nitrogen dioxide in the US(1). Occupational exposure to nitrogen dioxide may occur through inhalation and dermal contact with this compound at workplaces where nitrogen dioxide is produced or used or where combustion processes are important(SRC). The general population may be exposed to nitrogen dioxide via inhalation of ambient air and by smoking tobacco products(SRC).
(1) NIOSH; NOES. National Occupational Exposure Survey conducted from 1981-1983. Estimated numbers of employees potentially exposed to specific agents by 2-digit standard industrial classification (SIC). Available from; as of Jan 29, 2010: https://www.cdc.gov/noes/
A mean nitrogen dioxide concentration of 41.7 ppb was reported inside non-smoking patrol cars of the North Carolina State Highway patrol troopers, sampled in during a total of 25 days in August, September, and October 2001. Mean concentrations at a fixed ambient site and varying roadside locations were 30.4 and 49.9 ppb, respectively(1). A mean concentration of 1.9 ppm (detection limit, 0.5 ppm, 50% samples below detection limit; 14 ppm, max) was reported for nitrogen dioxide as a result of pollution analysis of 7,293 measurements in non-production departments, mainly storage, yard, loading, and shipping, from 147 pulp, paper, and paper product mills in 11 countries. The earliest measurements were from 1956, latest 1993, and the majority were from the 1980s and 1990s(2).
(1) Riediker M et al; Environ Sci Technol 37: 2084-2093 (2003)
(2) Teschke K et al; Am Ind Hyg Assoc J 60: 73-83 (1999)

11.2.12 Average Daily Intake

The estimated AVDI of nitric oxide and nitrogen dioxide for children in Silesia, Poland was reported as 420 ug for industrialized areas and 189 ug for non-industrialized area(1).
(1) Wesolowski JJ et al; J Exp Analysis Environ Epidem 2: 323-39 (1992)

12 Associated Disorders and Diseases

Associated Occupational Diseases with Exposure to the Compound

Bronchiolitis obliterans [Category: Airway Disease]

Pneumonitis, toxic [Category: Acute Poisoning]

Pulmonary disease, chronic obstructive [Category: Airway Disease]

13 Literature

13.1 Consolidated References

13.2 NLM Curated PubMed Citations

13.3 Thieme References

13.4 Chemical Co-Occurrences in Literature

13.5 Chemical-Gene Co-Occurrences in Literature

13.6 Chemical-Disease Co-Occurrences in Literature

14 Patents

14.1 Depositor-Supplied Patent Identifiers

14.2 WIPO PATENTSCOPE

14.3 Chemical Co-Occurrences in Patents

14.4 Chemical-Disease Co-Occurrences in Patents

14.5 Chemical-Gene Co-Occurrences in Patents

15 Interactions and Pathways

15.1 Protein Bound 3D Structures

15.1.1 Ligands from Protein Bound 3D Structures

PDBe Ligand Code
PDBe Structure Code
PDBe Conformer

15.2 Chemical-Target Interactions

16 Biological Test Results

16.1 BioAssay Results

17 Classification

17.1 MeSH Tree

17.2 NCI Thesaurus Tree

17.3 CAMEO Chemicals

17.4 UN GHS Classification

17.5 EPA TSCA and CDR Classification

17.6 MolGenie Organic Chemistry Ontology

18 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
  2. CAMEO Chemicals
    LICENSE
    CAMEO Chemicals and all other CAMEO products are available at no charge to those organizations and individuals (recipients) responsible for the safe handling of chemicals. However, some of the chemical data itself is subject to the copyright restrictions of the companies or organizations that provided the data.
    https://cameochemicals.noaa.gov/help/reference/terms_and_conditions.htm?d_f=false
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  3. ILO-WHO International Chemical Safety Cards (ICSCs)
  4. CAS Common Chemistry
    LICENSE
    The data from CAS Common Chemistry is provided under a CC-BY-NC 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc/4.0/
  5. EPA Acute Exposure Guideline Levels (AEGLs)
  6. EPA Chemicals under the TSCA
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  7. EPA Integrated Risk Information System (IRIS)
  8. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
  9. Hazardous Substances Data Bank (HSDB)
  10. New Zealand Environmental Protection Authority (EPA)
    LICENSE
    This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence.
    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  11. NJDOH RTK Hazardous Substance List
  12. Occupational Safety and Health Administration (OSHA)
    LICENSE
    Materials created by the federal government are generally part of the public domain and may be used, reproduced and distributed without permission. Therefore, content on this website which is in the public domain may be used without the prior permission of the U.S. Department of Labor (DOL). Warning: Some content - including both images and text - may be the copyrighted property of others and used by the DOL under a license.
    https://www.dol.gov/general/aboutdol/copyright
  13. Risk Assessment Information System (RAIS)
    LICENSE
    This work has been sponsored by the U.S. Department of Energy (DOE), Office of Environmental Management, Oak Ridge Operations (ORO) Office through a joint collaboration between United Cleanup Oak Ridge LLC (UCOR), Oak Ridge National Laboratory (ORNL), and The University of Tennessee, Ecology and Evolutionary Biology, The Institute for Environmental Modeling (TIEM). All rights reserved.
    https://rais.ornl.gov/
  14. The National Institute for Occupational Safety and Health (NIOSH)
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  15. California Safe Cosmetics Program (CSCP) Product Database
  16. Emergency Response Guidebook (ERG)
  17. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
    Copyright (c) 2022 Haz-Map(R). All rights reserved. Unless otherwise indicated, all materials from Haz-Map are copyrighted by Haz-Map(R). No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://haz-map.com/About
  18. NCI Thesaurus (NCIt)
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  19. Comparative Toxicogenomics Database (CTD)
    LICENSE
    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  20. Hazardous Chemical Information System (HCIS), Safe Work Australia
  21. NITE-CMC
    Nitrogen dioxide - FY2013 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/13-mhlw-2048e.html
    nitrogen dioxide - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0865e.html
  22. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
    The copyright for the editorial content of this source, the summaries of EU legislation and the consolidated texts, which is owned by the EU, is licensed under the Creative Commons Attribution 4.0 International licence.
    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
  23. Human Metabolome Database (HMDB)
    LICENSE
    HMDB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (HMDB) and the original publication (see the HMDB citing page). We ask that users who download significant portions of the database cite the HMDB paper in any resulting publications.
    http://www.hmdb.ca/citing
  24. Japan Chemical Substance Dictionary (Nikkaji)
  25. NIOSH Manual of Analytical Methods
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  26. Protein Data Bank in Europe (PDBe)
  27. SpectraBase
  28. Thieme Chemistry
    LICENSE
    The Thieme Chemistry contribution within PubChem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc-nd/4.0/
  29. Wikidata
  30. Wikipedia
  31. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
  32. PubChem
  33. GHS Classification (UNECE)
  34. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  35. PATENTSCOPE (WIPO)
CONTENTS