Nitrogen Dioxide

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  • Identifiers

    CAS number
    10102-44-0

    Molecular formula
    NO2

    SMILES
    N(=O)[O]

    Safety labels

    Oxidizer
    Oxidizer

    Compressed Gas
    Compressed Gas

    Corrosive
    Corrosive

    Acute Toxic
    Acute Toxic

  • Odor profile

    Fragrance
    Odorless 75.62%
    Sharp 28.45%
    Pungent 27.18%
    Fruity 25.13%
    Sour 24.93%
    Ethereal 20.06%
    Caramellic 18.59%
    Cheesy 17.4%
    Burnt 17.35%
    Fermented 17.21%

     

    Flavor
    Odorless 56.17%
    Pungent 40.04%
    Vinegar 32.01%
    Mustard 31.9%
    Sour 28.37%
    Formyl 26.77%
    Bitter 24.47%
    Sulfur 23.28%
    Mousy 22.55%
    Rotten 21.8%

     

    Odor impact est.
    Low

    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.

  • Properties

    XLogP3-AA
    -0.3

    pKa est.
    3.68 (weak acid)

    Molecular weight
    46.006 g/mol

    Melting point expt.

    • 15.3 °F (EPA, 1998)
    • -9.3 °C
    • -11.2 °C
    • 15 °F

    Boiling point

    • 70.07 °F at 760 mmHg (EPA, 1998)
    • 21.15 °C
    • 21.2 °C
    • 70 °F

    Flash point

    • 39.3 ˚C est.

    Solubility expt.

    • Reacts with water (NIOSH, 2024)
    • Reacts with water
    • Soluble in concentrated sulfuric and nitric acids
    • Solubility in water: reaction
    • Reacts

  • Synonyms

    • NITROGEN DIOXIDE
    • 10102-44-0
    • Dioxide, Nitrogen
    • Peroxide, Nitrogen
    • nitrosooxidanyl
    • nitryl
    • Azoto
    • Peroxyde d' azote
    • dioxidonitrogen(.)
    • nitrogen(IV) oxide
    • Dioxido de nitrogeno
    • Nitrogen peroxide, liquid
    • Nitrogen dioxide (liquid)
    • UNII-S7G510RUBH
    • NITROGEN OXIDE(NO2)
    • S7G510RUBH
    • DTXCID50974
    • CCRIS 4040
    • HSDB 718
    • Nitrogen dioxide, >=99.5%
    • ONO(.)
    • CHEBI:33101
    • (NO2)
    • NITROGEN DIOXIDE, LIQUEFIED
    • NITROGEN DIOXIDE, (LIQUID)
    • EINECS 233-272-6
    • MFCD00085341
    • NO2(.)
    • (NO2)(.)
    • NITROGEN DIOXIDE (NITROGEN OXIDES)
    • 233-272-6

  • Applications

    NO2, or nitrogen dioxide (CAS 10102-44-0), is primarily used as a feedstock in industrial nitric acid production via NOx chemistry, where it is absorbed and converted to HNO3; it also serves as an oxidizing and nitrosating/nitrating reagent in controlled laboratory-scale organic synthesis to furnish nitroaromatic and other nitrogen-containing intermediates; as a precursor to nitroaromatic dyes and pigments, NO2 participates in the production of certain specialty chemicals for coatings and inks; it may be used to generate nitro intermediates in pharmaceutical synthesis under strict process controls; and for analytical and environmental applications, NO2 is used as a reference gas and calibration standard for monitoring NOx emissions and gas-sensor development.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 37.98
    methanol 70.37
    isopropanol 29.88
    water 25.61
    ethyl acetate 10.12
    n-propanol 24.93
    acetone 31.23
    n-butanol 20.9
    acetonitrile 15.84
    DMF 339.33
    toluene 3.07
    isobutanol 17.81
    1,4-dioxane 32.41
    methyl acetate 16.93
    THF 48.17
    2-butanone 16.56
    n-pentanol 15.07
    sec-butanol 19.48
    n-hexane 0.86
    ethylene glycol 45.13
    NMP 139.79
    cyclohexane 0.74
    DMSO 252.51
    n-butyl acetate 7.56
    n-octanol 9.15
    chloroform 3.21
    n-propyl acetate 8.03
    acetic acid 34.22
    dichloromethane 5.99
    cyclohexanone 17.37
    propylene glycol 32.2
    isopropyl acetate 7.36
    DMAc 183.48
    2-ethoxyethanol 40.06
    isopentanol 18.38
    n-heptane 1.13
    ethyl formate 17.0
    1,2-dichloroethane 7.31
    n-hexanol 10.96
    2-methoxyethanol 88.77
    isobutyl acetate 4.45
    tetrachloromethane 1.22
    n-pentyl acetate 7.73
    transcutol 47.42
    n-heptanol 9.23
    ethylbenzene 2.05
    MIBK 9.67
    2-propoxyethanol 32.01
    tert-butanol 38.32
    MTBE 15.97
    2-butoxyethanol 22.83
    propionic acid 21.66
    o-xylene 4.32
    formic acid 52.53
    diethyl ether 11.37
    m-xylene 3.37
    p-xylene 2.82
    chlorobenzene 2.72
    dimethyl carbonate 20.17
    n-octane 0.57
    formamide 69.93
    cyclopentanone 28.7
    2-pentanone 13.45
    anisole 10.2
    cyclopentyl methyl ether 15.32
    gamma-butyrolactone 36.0
    1-methoxy-2-propanol 60.04
    pyridine 18.69
    3-pentanone 9.43
    furfural 41.88
    n-dodecane 0.66
    diethylene glycol 42.21
    diisopropyl ether 3.42
    tert-amyl alcohol 26.17
    acetylacetone 15.27
    n-hexadecane 0.7
    acetophenone 10.79
    methyl propionate 17.29
    isopentyl acetate 7.02
    trichloroethylene 7.49
    n-nonanol 8.55
    cyclohexanol 12.71
    benzyl alcohol 12.25
    2-ethylhexanol 6.4
    isooctanol 7.36
    dipropyl ether 7.19
    1,2-dichlorobenzene 3.19
    ethyl lactate 11.77
    propylene carbonate 16.76
    n-methylformamide 89.17
    2-pentanol 13.07
    n-pentane 1.21
    1-propoxy-2-propanol 22.25
    1-methoxy-2-propyl acetate 12.72
    2-(2-methoxypropoxy) propanol 23.77
    mesitylene 2.66
    ε-caprolactone 17.47
    p-cymene 2.67
    epichlorohydrin 30.43
    1,1,1-trichloroethane 2.89
    2-aminoethanol 49.64
    morpholine-4-carbaldehyde 101.07
    sulfolane 63.81
    2,2,4-trimethylpentane 1.01
    2-methyltetrahydrofuran 21.72
    n-hexyl acetate 9.48
    isooctane 0.78
    2-(2-butoxyethoxy)ethanol 29.06
    sec-butyl acetate 4.87
    tert-butyl acetate 9.55
    decalin 0.68
    glycerin 55.36
    diglyme 47.23
    acrylic acid 26.83
    isopropyl myristate 5.31
    n-butyric acid 18.43
    acetyl acetate 5.99
    di(2-ethylhexyl) phthalate 8.09
    ethyl propionate 8.35
    nitromethane 57.27
    1,2-diethoxyethane 11.83
    benzonitrile 8.62
    trioctyl phosphate 6.6
    1-bromopropane 4.09
    gamma-valerolactone 47.37
    n-decanol 7.14
    triethyl phosphate 5.9
    4-methyl-2-pentanol 8.45
    propionitrile 11.93
    vinylene carbonate 16.31
    1,1,2-trichlorotrifluoroethane 36.69
    DMS 10.29
    cumene 2.21
    2-octanol 6.58
    2-hexanone 9.26
    octyl acetate 7.54
    limonene 3.81
    1,2-dimethoxyethane 58.65
    ethyl orthosilicate 5.38
    tributyl phosphate 6.53
    diacetone alcohol 23.03
    N,N-dimethylaniline 12.68
    acrylonitrile 19.99
    aniline 10.41
    1,3-propanediol 43.57
    bromobenzene 1.73
    dibromomethane 3.57
    1,1,2,2-tetrachloroethane 8.03
    2-methyl-cyclohexyl acetate 6.15
    tetrabutyl urea 12.16
    diisobutyl methanol 4.74
    2-phenylethanol 9.84
    styrene 2.52
    dioctyl adipate 8.45
    dimethyl sulfate 41.82
    ethyl butyrate 6.77
    methyl lactate 26.43
    butyl lactate 10.97
    diethyl carbonate 5.4
    propanediol butyl ether 25.28
    triethyl orthoformate 6.28
    p-tert-butyltoluene 2.89
    methyl 4-tert-butylbenzoate 16.39
    morpholine 45.56
    tert-butylamine 17.92
    n-dodecanol 5.81
    dimethoxymethane 76.5
    ethylene carbonate 12.67
    cyrene 22.83
    2-ethoxyethyl acetate 11.1
    2-ethylhexyl acetate 5.29
    1,2,4-trichlorobenzene 4.31
    4-methylpyridine 18.78
    dibutyl ether 5.52
    2,6-dimethyl-4-heptanol 4.74
    DEF 40.78
    dimethyl isosorbide 27.09
    tetrachloroethylene 5.91
    eugenol 19.47
    triacetin 11.11
    span 80 19.31
    1,4-butanediol 21.61
    1,1-dichloroethane 4.14
    2-methyl-1-pentanol 12.55
    methyl formate 56.38
    2-methyl-1-butanol 17.03
    n-decane 0.82
    butyronitrile 11.92
    3,7-dimethyl-1-octanol 7.47
    1-chlorooctane 2.42
    1-chlorotetradecane 1.56
    n-nonane 0.74
    undecane 0.73
    tert-butylcyclohexane 0.81
    cyclooctane 0.42
    cyclopentanol 18.73
    tetrahydropyran 15.04
    tert-amyl methyl ether 14.39
    2,5,8-trioxanonane 39.42
    1-hexene 2.74
    2-isopropoxyethanol 23.65
    2,2,2-trifluoroethanol 21.53
    methyl butyrate 12.58

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction