Octadecanal

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  • Identifiers

    CAS number
    638-66-4

    Molecular formula
    C18H36O

    SMILES
    CCCCCCCCCCCCCCCCCC=O

    Safety labels

    Irritant
    Irritant

    Retention indicies (RI)

    • DB5: 2017.0
    • Carbowax: 2346.33

  • Odor profile

    Waxy 73.0%
    Fatty 69.65%
    Oily 39.67%
    Meaty 36.93%
    Citrus 35.8%
    Sweet 28.2%
    Fruit skin 27.21%
    Clean 27.13%
    Fresh 26.78%
    Soapy 26.01%

    Scent© AI

  • Properties

    XLogP3-AA
    8.1

    Molecular weight
    268.5 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Melting point expt.

    • 38.00 °C. @ 760.00 mm Hg

    Boiling point

    • 320.00 to 322.00 °C. @ 760.00 mm Hg

    Flash point est.
    158.97 ˚C

  • Synonyms

    • OCTADECANAL
    • Stearaldehyde
    • 638-66-4
    • Stearyl aldehyde
    • Octadecanaldehyde
    • Octadecyl aldehyde
    • n-Octadecanal
    • 1-octadecanal
    • PH4GZ7JT4C
    • EINECS 211-346-9
    • NSC 68100
    • UNII-PH4GZ7JT4C
    • MFCD03790007
    • NSC-68100
    • CHEBI:17034
    • DTXSID60213250
    • 1--Octadecanal
    • Octadecanal (9CI)
    • SCHEMBL3471
    • DTXCID60135741
    • NSC68100
    • LMFA06000098
    • AKOS025212736
    • CS-W004307
    • HY-W004307
    • AS-56476
    • NS00022609
    • O0368
    • C01838
    • Q7076690

  • Applications

    Octadecanal (stearyl aldehyde; CAS 638-66-4) is a C18 long‑chain fatty aldehyde used mainly as a versatile intermediate: it can be reduced to stearyl alcohol, oxidized to stearic acid, or converted into imines/oximes/acetals; these transformations are leveraged to prepare C18 surfactants/emulsifiers, lubricant and polymer–rubber processing additives, textile/leather auxiliaries and antistatic agents, as well as ingredients for personal‑care formulations and for excipient preparation; additionally, octadecanal is employed for surface modification (grafting C18 onto silica, cellulose, and polymers) to impart hydrophobicity, in hydrophobic coatings and nanoparticles, as a reference/reagent in studies of lipids, lipid oxidation, and membrane interactions, in aroma analysis at trace levels (waxy–fatty note) and more commonly as a precursor to aroma ingredients, and to form acetal/Schiff linkages for crosslinking or tailoring hydroxyl/amine‑containing polymers (e.g., PVA, polysaccharides).

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 45.02
    methanol 29.8
    isopropanol 78.47
    water 0.0
    ethyl acetate 434.58
    n-propanol 75.61
    acetone 202.06
    n-butanol 113.97
    acetonitrile 74.17
    DMF 274.98
    toluene 166.46
    isobutanol 87.96
    1,4-dioxane 373.32
    methyl acetate 207.27
    THF 1143.07
    2-butanone 310.59
    n-pentanol 86.92
    sec-butanol 102.18
    n-hexane 99.03
    ethylene glycol 2.64
    NMP 668.71
    cyclohexane 405.46
    DMSO 368.14
    n-butyl acetate 690.35
    n-octanol 111.1
    chloroform 946.66
    n-propyl acetate 546.47
    acetic acid 66.49
    dichloromethane 959.89
    cyclohexanone 1034.77
    propylene glycol 11.26
    isopropyl acetate 472.05
    DMAc 391.55
    2-ethoxyethanol 149.54
    isopentanol 161.96
    n-heptane 167.03
    ethyl formate 156.19
    1,2-dichloroethane 765.43
    n-hexanol 129.46
    2-methoxyethanol 155.24
    isobutyl acetate 399.65
    tetrachloromethane 283.36
    n-pentyl acetate 659.35
    transcutol 1006.69
    n-heptanol 103.18
    ethylbenzene 149.02
    MIBK 418.92
    2-propoxyethanol 230.27
    tert-butanol 182.91
    MTBE 350.31
    2-butoxyethanol 242.67
    propionic acid 96.92
    o-xylene 161.94
    formic acid 7.86
    diethyl ether 307.92
    m-xylene 149.44
    p-xylene 221.43
    chlorobenzene 312.77
    dimethyl carbonate 68.85
    n-octane 51.25
    formamide 19.02
    cyclopentanone 995.5
    2-pentanone 423.62
    anisole 282.68
    cyclopentyl methyl ether 710.0
    gamma-butyrolactone 858.71
    1-methoxy-2-propanol 206.67
    pyridine 440.08
    3-pentanone 332.13
    furfural 566.88
    n-dodecane 23.11
    diethylene glycol 63.76
    diisopropyl ether 214.29
    tert-amyl alcohol 194.58
    acetylacetone 502.33
    n-hexadecane 29.39
    acetophenone 354.03
    methyl propionate 260.47
    isopentyl acetate 646.97
    trichloroethylene 1138.94
    n-nonanol 120.88
    cyclohexanol 290.52
    benzyl alcohol 133.56
    2-ethylhexanol 197.62
    isooctanol 135.72
    dipropyl ether 640.07
    1,2-dichlorobenzene 413.16
    ethyl lactate 152.44
    propylene carbonate 521.29
    n-methylformamide 73.41
    2-pentanol 124.28
    n-pentane 58.41
    1-propoxy-2-propanol 342.27
    1-methoxy-2-propyl acetate 503.42
    2-(2-methoxypropoxy) propanol 242.74
    mesitylene 146.8
    ε-caprolactone 856.47
    p-cymene 181.68
    epichlorohydrin 913.5
    1,1,1-trichloroethane 929.55
    2-aminoethanol 15.07
    morpholine-4-carbaldehyde 491.3
    sulfolane 1356.91
    2,2,4-trimethylpentane 52.75
    2-methyltetrahydrofuran 851.53
    n-hexyl acetate 563.04
    isooctane 41.31
    2-(2-butoxyethoxy)ethanol 324.16
    sec-butyl acetate 474.15
    tert-butyl acetate 646.77
    decalin 126.79
    glycerin 20.87
    diglyme 793.12
    acrylic acid 56.22
    isopropyl myristate 236.72
    n-butyric acid 303.92
    acetyl acetate 265.57
    di(2-ethylhexyl) phthalate 128.45
    ethyl propionate 479.14
    nitromethane 190.65
    1,2-diethoxyethane 690.6
    benzonitrile 229.76
    trioctyl phosphate 111.61
    1-bromopropane 506.42
    gamma-valerolactone 1017.21
    n-decanol 80.58
    triethyl phosphate 310.64
    4-methyl-2-pentanol 113.87
    propionitrile 127.36
    vinylene carbonate 325.27
    1,1,2-trichlorotrifluoroethane 471.48
    DMS 260.6
    cumene 126.5
    2-octanol 108.44
    2-hexanone 442.6
    octyl acetate 241.4
    limonene 361.5
    1,2-dimethoxyethane 567.68
    ethyl orthosilicate 324.53
    tributyl phosphate 168.48
    diacetone alcohol 420.33
    N,N-dimethylaniline 216.43
    acrylonitrile 109.76
    aniline 149.86
    1,3-propanediol 44.78
    bromobenzene 402.28
    dibromomethane 697.41
    1,1,2,2-tetrachloroethane 1249.97
    2-methyl-cyclohexyl acetate 516.34
    tetrabutyl urea 239.2
    diisobutyl methanol 202.54
    2-phenylethanol 163.09
    styrene 175.99
    dioctyl adipate 334.61
    dimethyl sulfate 172.15
    ethyl butyrate 751.88
    methyl lactate 86.34
    butyl lactate 314.81
    diethyl carbonate 355.33
    propanediol butyl ether 153.22
    triethyl orthoformate 572.35
    p-tert-butyltoluene 171.45
    methyl 4-tert-butylbenzoate 375.76
    morpholine 526.03
    tert-butylamine 156.79
    n-dodecanol 60.47
    dimethoxymethane 222.65
    ethylene carbonate 334.26
    cyrene 253.21
    2-ethoxyethyl acetate 536.86
    2-ethylhexyl acetate 586.39
    1,2,4-trichlorobenzene 461.41
    4-methylpyridine 423.76
    dibutyl ether 538.76
    2,6-dimethyl-4-heptanol 202.54
    DEF 494.8
    dimethyl isosorbide 674.05
    tetrachloroethylene 733.49
    eugenol 247.49
    triacetin 495.76
    span 80 242.48
    1,4-butanediol 18.65
    1,1-dichloroethane 624.65
    2-methyl-1-pentanol 124.71
    methyl formate 56.86
    2-methyl-1-butanol 132.3
    n-decane 56.6
    butyronitrile 201.31
    3,7-dimethyl-1-octanol 174.32
    1-chlorooctane 225.1
    1-chlorotetradecane 72.22
    n-nonane 58.98
    undecane 33.26
    tert-butylcyclohexane 97.37
    cyclooctane 117.94
    cyclopentanol 254.36
    tetrahydropyran 778.79
    tert-amyl methyl ether 341.49
    2,5,8-trioxanonane 466.56
    1-hexene 190.14
    2-isopropoxyethanol 169.15
    2,2,2-trifluoroethanol 32.76
    methyl butyrate 653.98

    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

Botanical

Name CAS Botanical Proportion
Narcissus tazetta absolute 2 8023-75-4 Narcissus tazetta L., fam. Amaryllidaceae 0.1%
Betel leaf Sanchi (India) Piper betle L. var. Sanchi, fam. Piperaceae 2.69%
Lime (Persian) (Japan) Citrus latifolia Tanaka, fam. Rutaceae 0.02%
Cnidium officinale (Korea) Cnidium officinale Makino, fam. Apiaceae (Umbelliferae) 0.1%