1-Butanethiol

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  • Identifiers

    CAS number
    109-79-5

    Molecular formula
    C4H10S

    SMILES
    CCCCS

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Sulfurous 89.22%
    Meaty 81.47%
    Onion 69.49%
    Garlic 64.43%
    Vegetable 62.26%
    Savory 61.74%
    Roasted 58.14%
    Alliaceous 58.06%
    Fatty 51.35%
    Coffee 46.92%

    Scent© AI

    Odor threshold>

    • Odor Threshold Low: 0.00073 [mmHg]. Odor Threshold High: 0.001 [mmHg]. Detection odor threshold from AIHA (mean = 0.001 ppm)
    • The odor threshold /for n-butyl mercaptan/ ranges from about 0.001 to 0.0001 ppm, depending on circumstances. The readily noticeable level is about 0.1 to 1 ppm.
    • Odor perception threshold is reported to be 6.0 ug/L or 0.012 ug/L.

  • Properties

    XLogP3-AA
    2.3

    Molecular weight
    90.19 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -176.2 °F (USCG, 1999)
    • -115.9 °C
    • -119 °C
    • -116 °C
    • 176.2 °F
    • -176 °F

    Boiling point

    • 229.3 °F at 760 mmHg (USCG, 1999)
    • 97.2 - 101.7 °C
    • Forms azeotropic mixture with butyl alcohol (bp: 97.8 °C; 85.16% butanethiol) & with butyl alcohol and water; mobile
    • 98.50 °C. @ 760.00 mm Hg
    • 98 °C
    • 209 °F

    Flash point est.
    6.47 ˚C

    Flash point expt.

    • 55 °F (USCG, 1999)
    • 2 °C
    • 35 °F (2 °C) (Closed cup)
    • 2 °C c.c.
    • 55 °F
    • 35 °F

    Solubility expt.

    • 0.06 % (NIOSH, 2024)
    • Slightly soluble in chloroform
    • Very soluble in alcohol, ether, liquid hydrogen sulfide
    • In water, 595 mg/L at 25 °C
    • 0.597 mg/mL at 20 °C
    • Solubility in water, g/100ml: 0.06
    • 0.6 g in 100 ml water; slightly soluble in oils
    • 1 ml in 1 ml 95% alcohol (in ethanol)
    • 0.06%

  • Synonyms

    • 1-Butanethiol
    • Butanethiol
    • butane-1-thiol
    • 109-79-5
    • BUTYL MERCAPTAN
    • n-Butyl mercaptan
    • n-Butanethiol
    • Butylthiol
    • n-Butylmercaptan
    • Thiobutyl alcohol
    • 1-Butyl mercaptan
    • 1-Mercaptobutane
    • butylmercaptan
    • n-Butyl thioalcohol
    • n-Butylthiol
    • Bear skunk
    • Caswell No. 119D
    • Normal butyl thioalcohol
    • Mercaptan C4
    • FEMA No. 3478
    • HSDB 290
    • 4-butanethiol
    • n-C4H9SH
    • NCI-C60866
    • EINECS 203-705-3
    • EPA Pesticide Chemical Code 125001
    • BRN 1730908
    • DTXSID6026824
    • UNII-77OY909F30
    • AI3-22954
    • BUTYLMERCAPTAN, N-
    • 1-BUTANETHIOL [FHFI]
    • DTXCID406824
    • N-BUTYL MERCAPTAN [MI]
    • 1-BUTYL MERCAPTAN [HSDB]
    • 4-01-00-01555 (Beilstein Handbook Reference)
    • 77OY909F30
    • n-butane-1-thiol
    • 32812-85-4
    • MFCD00004905
    • nButanethiol
    • nButylmercaptan
    • 1Mercaptobutane
    • butane thiol
    • n-butanthiol
    • n-butyl mercaptan, sodium salt
    • nButyl mercaptan
    • 1-butylthiol
    • butyl thioalcohol
    • 1-butylmercaptan
    • n-butyl mercaptan, lithium salt
    • nButyl thioalcohol
    • n-butyl mercaptan, Ag(+1) salt
    • n-butyl mercaptan, potassium salt
    • n-butyl mercaptan, tin (+2) salt
    • n-BuSH
    • n-butyl mercaptan, lead (+2) salt
    • BUSH
    • Butanethiol (OSHA)
    • n-butyl mercaptan, copper (+1) salt
    • n-butyl mercaptan, silver (+2) salt
    • n-butyl mercaptan, geranium (+2) salt
    • n-butyl mercaptan, molybdenum (+3) salt
    • 1-Butanethiol, 99%
    • n-butyl mercaptan, 14C,1-(35)S-labeled cpd
    • 1-Butanethiol, >=98%
    • n-Butyl mercaptan (ACGIH)
    • Butyl mercaptan (DOT:OSHA)
    • n-butyl mercaptan, 2-(14)C,2-(35)s-labeled cpd
    • CHEMBL3188256
    • n-butyl mercaptan, 1,2-(14)C,2-(35) S-labeled cpd
    • FEMA 3478
    • CHEBI:177389
    • 1-Butanethiol, analytical standard
    • Tox21_200811
    • BUTYL MERCAPTAN (BUTANETHIOL)
    • AKOS009031443
    • USEPA/OPP Pesticide Code: 125001
    • NCGC00248839-01
    • NCGC00258365-01
    • CAS-109-79-5
    • 1-Butanethiol, purum, >=97.0% (GC)
    • DB-003605
    • B0685
    • NS00020726
    • EN300-19345
    • A802088
    • Q195823

  • Applications

    1-Butanethiol (CAS 109-79-5) is a sulfur-containing organic compound with a strong skunky odor that serves multiple purposes: at trace levels it is blended into natural gas and LPG as a safety odorant; in organic synthesis it supplies thiol groups for producing thioesters, sulfides and pharmaceutical intermediates; in the rubber industry it functions as a vulcanization accelerator and polymer property modifier; in flavor and fragrance work, careful dilution imparts buttery, onion-garlic or cheesy notes to food and tobacco products; additionally, 1-butanethiol is investigated as a corrosion inhibitor, agrochemical precursor, surface-active agent and specialty coating additive.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 1417.02
    methanol 1361.98
    isopropanol 944.72
    water 0.41
    ethyl acetate 685.4
    n-propanol 1045.75
    acetone 1286.25
    n-butanol 1189.79
    acetonitrile 597.67
    DMF 499.81
    toluene 315.62
    isobutanol 626.21
    1,4-dioxane 1296.75
    methyl acetate 486.62
    THF 2715.91
    2-butanone 863.36
    n-pentanol 682.05
    sec-butanol 721.33
    n-hexane 413.67
    ethylene glycol 137.86
    NMP 528.3
    cyclohexane 602.47
    DMSO 1018.59
    n-butyl acetate 1641.48
    n-octanol 338.72
    chloroform 1131.03
    n-propyl acetate 502.58
    acetic acid 767.31
    dichloromethane 989.59
    cyclohexanone 1275.09
    propylene glycol 179.67
    isopropyl acetate 412.17
    DMAc 259.91
    2-ethoxyethanol 493.81
    isopentanol 735.18
    n-heptane 671.82
    ethyl formate 393.38
    1,2-dichloroethane 657.22
    n-hexanol 1402.74
    2-methoxyethanol 882.75
    isobutyl acetate 304.72
    tetrachloromethane 384.93
    n-pentyl acetate 437.78
    transcutol 1547.48
    n-heptanol 422.83
    ethylbenzene 129.73
    MIBK 392.06
    2-propoxyethanol 1189.37
    tert-butanol 859.01
    MTBE 748.35
    2-butoxyethanol 510.04
    propionic acid 479.28
    o-xylene 144.59
    formic acid 154.93
    diethyl ether 1363.69
    m-xylene 171.64
    p-xylene 164.15
    chlorobenzene 374.1
    dimethyl carbonate 85.39
    n-octane 136.84
    formamide 170.85
    cyclopentanone 1198.3
    2-pentanone 903.73
    anisole 229.61
    cyclopentyl methyl ether 983.87
    gamma-butyrolactone 872.65
    1-methoxy-2-propanol 542.45
    pyridine 817.81
    3-pentanone 518.01
    furfural 651.13
    n-dodecane 62.53
    diethylene glycol 543.6
    diisopropyl ether 330.61
    tert-amyl alcohol 581.09
    acetylacetone 533.87
    n-hexadecane 68.28
    acetophenone 186.86
    methyl propionate 351.44
    isopentyl acetate 944.21
    trichloroethylene 890.62
    n-nonanol 283.14
    cyclohexanol 799.23
    benzyl alcohol 194.09
    2-ethylhexanol 773.41
    isooctanol 287.6
    dipropyl ether 1278.33
    1,2-dichlorobenzene 259.95
    ethyl lactate 117.65
    propylene carbonate 441.4
    n-methylformamide 330.36
    2-pentanol 657.92
    n-pentane 449.28
    1-propoxy-2-propanol 1016.46
    1-methoxy-2-propyl acetate 549.79
    2-(2-methoxypropoxy) propanol 288.33
    mesitylene 113.57
    ε-caprolactone 790.29
    p-cymene 188.29
    epichlorohydrin 867.4
    1,1,1-trichloroethane 661.72
    2-aminoethanol 294.56
    morpholine-4-carbaldehyde 571.38
    sulfolane 783.42
    2,2,4-trimethylpentane 100.85
    2-methyltetrahydrofuran 1716.98
    n-hexyl acetate 456.77
    isooctane 89.93
    2-(2-butoxyethoxy)ethanol 502.95
    sec-butyl acetate 278.65
    tert-butyl acetate 399.21
    decalin 110.58
    glycerin 199.29
    diglyme 812.78
    acrylic acid 298.04
    isopropyl myristate 181.51
    n-butyric acid 895.77
    acetyl acetate 339.0
    di(2-ethylhexyl) phthalate 137.54
    ethyl propionate 288.75
    nitromethane 624.8
    1,2-diethoxyethane 1030.54
    benzonitrile 320.04
    trioctyl phosphate 124.03
    1-bromopropane 912.44
    gamma-valerolactone 1017.32
    n-decanol 210.85
    triethyl phosphate 160.22
    4-methyl-2-pentanol 287.42
    propionitrile 547.24
    vinylene carbonate 324.87
    1,1,2-trichlorotrifluoroethane 454.8
    DMS 188.22
    cumene 86.78
    2-octanol 252.4
    2-hexanone 649.3
    octyl acetate 229.75
    limonene 439.94
    1,2-dimethoxyethane 912.95
    ethyl orthosilicate 183.88
    tributyl phosphate 158.68
    diacetone alcohol 372.12
    N,N-dimethylaniline 131.33
    acrylonitrile 413.02
    aniline 331.5
    1,3-propanediol 518.54
    bromobenzene 364.5
    dibromomethane 948.11
    1,1,2,2-tetrachloroethane 646.98
    2-methyl-cyclohexyl acetate 342.93
    tetrabutyl urea 191.94
    diisobutyl methanol 377.55
    2-phenylethanol 371.77
    styrene 178.99
    dioctyl adipate 218.66
    dimethyl sulfate 105.16
    ethyl butyrate 695.47
    methyl lactate 116.03
    butyl lactate 248.59
    diethyl carbonate 274.61
    propanediol butyl ether 326.1
    triethyl orthoformate 403.0
    p-tert-butyltoluene 174.06
    methyl 4-tert-butylbenzoate 177.15
    morpholine 1422.38
    tert-butylamine 633.6
    n-dodecanol 165.95
    dimethoxymethane 489.06
    ethylene carbonate 318.52
    cyrene 192.26
    2-ethoxyethyl acetate 427.03
    2-ethylhexyl acetate 805.0
    1,2,4-trichlorobenzene 286.76
    4-methylpyridine 644.44
    dibutyl ether 661.67
    2,6-dimethyl-4-heptanol 377.55
    DEF 525.16
    dimethyl isosorbide 476.27
    tetrachloroethylene 559.46
    eugenol 196.31
    triacetin 251.14
    span 80 359.29
    1,4-butanediol 173.46
    1,1-dichloroethane 768.77
    2-methyl-1-pentanol 451.67
    methyl formate 227.98
    2-methyl-1-butanol 633.36
    n-decane 122.35
    butyronitrile 893.12
    3,7-dimethyl-1-octanol 328.68
    1-chlorooctane 266.39
    1-chlorotetradecane 100.48
    n-nonane 143.57
    undecane 81.48
    tert-butylcyclohexane 104.42
    cyclooctane 179.97
    cyclopentanol 813.36
    tetrahydropyran 2048.29
    tert-amyl methyl ether 470.1
    2,5,8-trioxanonane 513.42
    1-hexene 807.11
    2-isopropoxyethanol 331.74
    2,2,2-trifluoroethanol 129.15
    methyl butyrate 425.57

    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