Isobutane

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  • Identifiers

    CAS number
    75-28-5

    Molecular formula
    C4H10

    SMILES
    CC(C)C

    Safety labels

    Flammable
    Flammable

    Compressed Gas
    Compressed Gas

  • Odor profile

    Fragrance
    Ethereal 65.23%
    Gassy 40.47%
    Solvent 39.65%
    Fresh 39.1%
    Camphoreous 36.85%
    Sweet 32.95%
    Fermented 32.24%
    Pungent 30.2%
    Alcoholic 27.81%
    Mint 27.35%

     

    Flavor
    Fishy 35.93%
    Ethereal 34.45%
    Solvent 29.29%
    Pungent 25.82%
    Gasoline 23.17%
    Ammonia 21.65%
    Rotten 20.97%
    Glue 20.35%
    Alkane 20.1%
    Yeasty 19.89%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    2.1

    pKa est.
    10.77 (weak base)

    Molecular weight
    58.12 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -255 °F (NIOSH, 2024)
    • -138.3 °C
    • -160 °C
    • -216.9 °F
    • -255 °F

    Boiling point

    • 10.8 °F at 760 mmHg (USCG, 1999)
    • -11.7 °C
    • -12 °C
    • 10.8 °F
    • 11 °F

    Flash point

    • -74.97 ˚C est.
    • -117 °F (USCG, 1999)
    • -82.99 °C (-117.38 °F) - closed cup
    • Flammable gas
    • -117 °F
    • NA (Gas)

    Solubility expt.

    • Slight (NIOSH, 2024)
    • In water, 48.9 mg/L at 25 °C
    • Soluble in ethanol, ether, chloroform
    • Solubility in water at 20 °C: none
    • Slight

  • Synonyms

    • ISOBUTANE
    • 2-Methylpropane
    • 75-28-5
    • Trimethylmethane
    • Propane, 2-methyl-
    • 1,1-Dimethylethane
    • iso-butane
    • R 600a
    • Caswell No. 503A
    • HSDB 608
    • R-600a
    • EINECS 200-857-2
    • Isobutane [NF]
    • UNII-BXR49TP611
    • EPA Pesticide Chemical Code 097101
    • BXR49TP611
    • CHEBI:30363
    • E943b
    • (CH3)2CH-CH3
    • DTXSID1026401
    • EC 200-857-2
    • Isobutane (NF)
    • ISOBUTANE (II)
    • ISOBUTANE [II]
    • ISOBUTANE (MART.)
    • ISOBUTANE [MART.]
    • 2-METHYL-D3-PROPANE-1,1,1,3,3,3-D6
    • dimethylethane
    • Methylpropane
    • iso butane
    • tert-Butane
    • 2-methylpropyl
    • i-Butane
    • H-tBu
    • ISOBUTANE [FCC]
    • iso-C4H10
    • 2-Methylpropane, 99%
    • ISOBUTANE [HSDB]
    • ISOBUTANE [VANDF]
    • 2-Methylpropane, puriss.
    • PROPANE, 2-METHYL
    • ISOBUTANE [WHO-DD]
    • DTXCID806401
    • 2-Methylpropane, 99.995%
    • CHEMBL2106398
    • DTXSID60963546
    • MFCD00008926
    • AKOS015917447
    • UN 1969
    • DB-360584
    • I0090
    • NS00007329
    • D04623
    • Q407225
    • 200-857-2

  • Applications

    Isobutane (CAS 75-28-5) is a C4 hydrocarbon gas with primary applications as a refrigerant (R-600a) in domestic refrigerators and small-scale air conditioning, as an aerosol propellant in cosmetics and household products, as a blowing agent for polyurethane foams and other polymer foams, and as a feedstock/intermediate for the production of isobutylene and related derivatives such as polyisobutylene, supporting applications in petrochemical, polymer and related industries.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 177.9
    methanol 141.56
    isopropanol 185.62
    water 0.43
    ethyl acetate 159.81
    n-propanol 190.7
    acetone 147.85
    n-butanol 239.17
    acetonitrile 83.79
    DMF 128.58
    toluene 109.88
    isobutanol 158.46
    1,4-dioxane 243.39
    methyl acetate 122.44
    THF 479.91
    2-butanone 174.24
    n-pentanol 141.54
    sec-butanol 229.8
    n-hexane 350.17
    ethylene glycol 48.94
    NMP 233.28
    cyclohexane 336.64
    DMSO 112.86
    n-butyl acetate 332.24
    n-octanol 234.87
    chloroform 311.94
    n-propyl acetate 114.07
    acetic acid 142.82
    dichloromethane 188.09
    cyclohexanone 274.85
    propylene glycol 97.74
    isopropyl acetate 128.89
    DMAc 156.69
    2-ethoxyethanol 113.01
    isopentanol 203.72
    n-heptane 655.47
    ethyl formate 68.17
    1,2-dichloroethane 125.04
    n-hexanol 496.21
    2-methoxyethanol 180.54
    isobutyl acetate 99.56
    tetrachloromethane 124.72
    n-pentyl acetate 142.3
    transcutol 362.75
    n-heptanol 231.87
    ethylbenzene 78.97
    MIBK 119.57
    2-propoxyethanol 354.71
    tert-butanol 282.13
    MTBE 288.26
    2-butoxyethanol 209.41
    propionic acid 141.51
    o-xylene 93.44
    formic acid 32.09
    diethyl ether 251.64
    m-xylene 97.48
    p-xylene 97.11
    chlorobenzene 103.95
    dimethyl carbonate 47.35
    n-octane 162.82
    formamide 28.0
    cyclopentanone 282.5
    2-pentanone 172.22
    anisole 109.09
    cyclopentyl methyl ether 324.9
    gamma-butyrolactone 215.17
    1-methoxy-2-propanol 194.37
    pyridine 162.2
    3-pentanone 159.05
    furfural 144.94
    n-dodecane 100.0
    diethylene glycol 162.97
    diisopropyl ether 149.94
    tert-amyl alcohol 296.79
    acetylacetone 128.56
    n-hexadecane 103.72
    acetophenone 89.1
    methyl propionate 122.67
    isopentyl acetate 284.47
    trichloroethylene 190.31
    n-nonanol 217.15
    cyclohexanol 272.22
    benzyl alcohol 72.77
    2-ethylhexanol 442.07
    isooctanol 183.34
    dipropyl ether 548.66
    1,2-dichlorobenzene 94.73
    ethyl lactate 74.16
    propylene carbonate 146.71
    n-methylformamide 59.84
    2-pentanol 221.52
    n-pentane 251.2
    1-propoxy-2-propanol 443.55
    1-methoxy-2-propyl acetate 237.5
    2-(2-methoxypropoxy) propanol 217.2
    mesitylene 80.69
    ε-caprolactone 219.49
    p-cymene 142.64
    epichlorohydrin 174.88
    1,1,1-trichloroethane 208.66
    2-aminoethanol 98.78
    morpholine-4-carbaldehyde 176.16
    sulfolane 240.44
    2,2,4-trimethylpentane 124.91
    2-methyltetrahydrofuran 394.42
    n-hexyl acetate 224.14
    isooctane 103.73
    2-(2-butoxyethoxy)ethanol 259.66
    sec-butyl acetate 106.79
    tert-butyl acetate 174.09
    decalin 130.04
    glycerin 109.81
    diglyme 315.77
    acrylic acid 105.03
    isopropyl myristate 151.42
    n-butyric acid 216.79
    acetyl acetate 104.86
    di(2-ethylhexyl) phthalate 104.82
    ethyl propionate 118.62
    nitromethane 99.38
    1,2-diethoxyethane 219.19
    benzonitrile 83.18
    trioctyl phosphate 100.81
    1-bromopropane 202.01
    gamma-valerolactone 226.89
    n-decanol 179.66
    triethyl phosphate 123.6
    4-methyl-2-pentanol 150.15
    propionitrile 119.19
    vinylene carbonate 97.83
    1,1,2-trichlorotrifluoroethane 169.3
    DMS 106.39
    cumene 71.26
    2-octanol 165.59
    2-hexanone 146.84
    octyl acetate 177.73
    limonene 283.48
    1,2-dimethoxyethane 194.26
    ethyl orthosilicate 138.59
    tributyl phosphate 116.22
    diacetone alcohol 187.07
    N,N-dimethylaniline 96.54
    acrylonitrile 90.48
    aniline 112.92
    1,3-propanediol 128.12
    bromobenzene 111.08
    dibromomethane 204.76
    1,1,2,2-tetrachloroethane 214.32
    2-methyl-cyclohexyl acetate 223.59
    tetrabutyl urea 143.6
    diisobutyl methanol 255.96
    2-phenylethanol 153.43
    styrene 82.6
    dioctyl adipate 161.6
    dimethyl sulfate 55.71
    ethyl butyrate 233.06
    methyl lactate 81.45
    butyl lactate 135.18
    diethyl carbonate 145.41
    propanediol butyl ether 179.31
    triethyl orthoformate 217.74
    p-tert-butyltoluene 156.15
    methyl 4-tert-butylbenzoate 162.1
    morpholine 281.56
    tert-butylamine 275.93
    n-dodecanol 157.55
    dimethoxymethane 116.34
    ethylene carbonate 92.95
    cyrene 118.91
    2-ethoxyethyl acetate 123.51
    2-ethylhexyl acetate 262.54
    1,2,4-trichlorobenzene 118.83
    4-methylpyridine 147.5
    dibutyl ether 318.52
    2,6-dimethyl-4-heptanol 255.96
    DEF 163.2
    dimethyl isosorbide 283.53
    tetrachloroethylene 159.99
    eugenol 136.36
    triacetin 166.33
    span 80 301.97
    1,4-butanediol 57.24
    1,1-dichloroethane 176.15
    2-methyl-1-pentanol 134.05
    methyl formate 42.71
    2-methyl-1-butanol 196.5
    n-decane 154.9
    butyronitrile 148.47
    3,7-dimethyl-1-octanol 249.69
    1-chlorooctane 209.72
    1-chlorotetradecane 110.0
    n-nonane 179.27
    undecane 118.25
    tert-butylcyclohexane 141.56
    cyclooctane 188.75
    cyclopentanol 254.68
    tetrahydropyran 394.64
    tert-amyl methyl ether 276.94
    2,5,8-trioxanonane 261.13
    1-hexene 320.12
    2-isopropoxyethanol 111.74
    2,2,2-trifluoroethanol 45.58
    methyl butyrate 133.93

    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