N-Acetyl-L-Cysteine

Overview IFRA Request a quote

  • Identifiers

    CAS number
    616-91-1

    Molecular formula
    C5H9NO3S

    SMILES
    CC(=O)N[C@@H](CS)C(=O)O

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Meaty 57.72%
    Odorless 53.4%
    Savory 48.74%
    Sulfurous 43.37%
    Roasted 34.01%
    Cooked 30.83%
    Sweet 21.8%
    Beefy 21.58%
    Onion 20.22%
    Burnt 20.22%

     

    Flavor
    Odorless 63.79%
    Mild 32.87%
    Very mild 26.83%
    Bland 26.03%
    Cooked 24.05%
    Sulfury 23.69%
    Yeast 22.91%
    Sweet-like 21.83%
    Roasted 20.73%
    Faint 20.49%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    0.4

    pKa est.
    8.35 (weak base)

    Molecular weight
    163.2 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    356°C

    Melting point expt.

    • 109-110
    • 109.5 °C

    Flash point

    • 167.92 ˚C est.

    Solubility expt.

    • 1 G IN 5 ML WATER, 4 ML ALC; PRACTICALLY INSOL IN CHLOROFORM & ETHER
    • Soluble in water, alcohol, hot isopropyl alcohol, methyl acetate, and ethyl acetate
    • >24.5 [ug/mL] (The mean of the results at pH 7.4)

  • Synonyms

    • N-Acetyl-L-cysteine
    • acetylcysteine
    • 616-91-1
    • N-Acetylcysteine
    • mercapturic acid
    • Acetadote
    • L-Acetylcysteine
    • Fluimucetin
    • Respaire
    • N-Acetyl cysteine
    • Acetilcisteina
    • Brunac
    • Acetylcysteinum
    • Syntemucol
    • Tixair
    • L-Cysteine, N-acetyl-
    • Mucolyticum-Lappe
    • N-Acetyl-3-mercaptoalanine
    • Mucolyticum
    • Cetylev
    • (2R)-2-acetamido-3-sulfanylpropanoic acid
    • Neo-fluimucil
    • Cysteine, N-acetyl-, L-
    • N-Acetyl-L-(+)-cysteine
    • Mercapturic acid, (R)-
    • Fluatox
    • Fluimicil
    • Mucolator
    • Mucret
    • (R)-mercapturic acid
    • Oristar nalc
    • MUCOSIL-10
    • MUCOSIL-20
    • N-acetyi-l-cysteine
    • L-alpha-Acetamido-beta-mercaptopropionic acid
    • Mucocedyl
    • NSC-111180
    • WYQ7N0BPYC
    • Muco sanigen
    • DTXSID5020021
    • DTXCID4021
    • (R)-2-acetylamino-3-mercaptopropanoic acid
    • (2R)-2-acetylamino-3-sulfanylpropanoic acid
    • CHEBI:28939
    • NSC111180
    • DTXSID8048105
    • Jenapharm
    • Yournac
    • Bromuc
    • BronchoFips
    • Genac
    • Siran
    • Fluimucil long
    • MPectil
    • Fluimucil n
    • Broncho Fips
    • Respi-nac
    • N Acetylcysteine
    • Mucopect, Dampo
    • M Pectil
    • Sanigen, Muco
    • En-cys
    • Larylin NAC
    • Acid, Mercapturic
    • NAC Zambon
    • A-cys
    • NAC, Bisolvon
    • Tris-NAC
    • Zambon, NAC
    • Fluimucil 600
    • Zinc, Acetylcysteine
    • N Acetyl L cysteine
    • Oronac 600
    • Sodium, Acetylcysteine
    • Acetylcysteine Solution
    • Acetylcystein, mentopin
    • Acetylcysteine Injection
    • RefChem:6371
    • NAC AL
    • CorniSol Eye Wash Drops
    • Acc-600
    • Hydrochloride, Acetylcysteine
    • Monosodium Salt Acetylcysteine
    • Acetylcysteine, Monosodium Salt
    • Monoammonium Salt Acetylcysteine
    • DTXCID6028076
    • CHEBI:22198
    • R05CB01
    • S01XA08
    • V03AB23
    • 210-498-3
    • Broncholysin
    • Mucomyst
    • Parvolex
    • Fluimucil
    • Acetein
    • N-Acetyl-cysteine
    • Airbron
    • Flumucetin
    • Mucosolvin
    • Fluprowit
    • Mucofilin
    • Mucosil
    • Fabrol
    • Inspir
    • Fluimicil Infantil
    • (R)-2-Acetamido-3-mercaptopropanoic acid
    • Lysomucil
    • acetyl cysteine
    • Ac-Cys-OH
    • Mucolyticum Lappe
    • Mucolytikum Lappe
    • Acetyl-L-cysteine
    • Exomuc
    • NAC-TB
    • MFCD00004880
    • component of Naxid
    • (2R)-2-Acetamido-3-sulfanyl-propanoic acid
    • C5H9NO3S
    • NSC 111180
    • N-acetyl-(R)-cysteine
    • cysteine, N-acetyl-
    • RK-0202
    • MLS000028419
    • NCGC00022304-05
    • SMR000058377
    • Flumil
    • 616-91-1

  • Applications

    N-Acetyl-L-Cysteine (CAS 616-91-1) is widely used in pharmaceuticals and chemical manufacturing as a mucolytic agent, an antidote for acetaminophen overdose, and as a versatile precursor for the synthesis of cysteine-containing compounds; it also serves as a reducing agent and antioxidant in various chemical processes and formulations, is used in cosmetics/personal care in some formulations for its antioxidant/conditioning properties, and is evaluated as a processing aid or stabilizer in specialty plastics and coatings under controlled conditions.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 85.71
    methanol 156.7
    isopropanol 45.21
    water 227.12
    ethyl acetate 8.52
    n-propanol 49.08
    acetone 57.66
    n-butanol 34.12
    acetonitrile 16.04
    DMF 489.56
    toluene 1.16
    isobutanol 25.23
    1,4-dioxane 31.84
    methyl acetate 12.56
    THF 54.62
    2-butanone 21.87
    n-pentanol 22.64
    sec-butanol 28.94
    n-hexane 0.87
    ethylene glycol 123.57
    NMP 156.19
    cyclohexane 0.39
    DMSO 521.57
    n-butyl acetate 7.29
    n-octanol 10.01
    chloroform 2.55
    n-propyl acetate 6.64
    acetic acid 47.67
    dichloromethane 4.72
    cyclohexanone 25.18
    propylene glycol 72.13
    isopropyl acetate 5.78
    DMAc 269.7
    2-ethoxyethanol 89.91
    isopentanol 23.7
    n-heptane 0.68
    ethyl formate 40.75
    1,2-dichloroethane 6.49
    n-hexanol 14.46
    2-methoxyethanol 192.72
    isobutyl acetate 3.56
    tetrachloromethane 1.39
    n-pentyl acetate 6.46
    transcutol 50.23
    n-heptanol 9.93
    ethylbenzene 1.84
    MIBK 10.83
    2-propoxyethanol 53.39
    tert-butanol 42.39
    MTBE 9.95
    2-butoxyethanol 30.84
    propionic acid 23.03
    o-xylene 2.55
    formic acid 155.4
    diethyl ether 8.16
    m-xylene 2.05
    p-xylene 2.33
    chlorobenzene 1.6
    dimethyl carbonate 10.74
    n-octane 0.5
    formamide 138.63
    cyclopentanone 40.76
    2-pentanone 17.63
    anisole 7.84
    cyclopentyl methyl ether 10.39
    gamma-butyrolactone 44.22
    1-methoxy-2-propanol 86.87
    pyridine 10.24
    3-pentanone 10.31
    furfural 66.16
    n-dodecane 0.47
    diethylene glycol 91.83
    diisopropyl ether 1.94
    tert-amyl alcohol 29.04
    acetylacetone 24.86
    n-hexadecane 0.5
    acetophenone 12.16
    methyl propionate 11.51
    isopentyl acetate 6.99
    trichloroethylene 6.57
    n-nonanol 8.89
    cyclohexanol 12.3
    benzyl alcohol 15.58
    2-ethylhexanol 6.63
    isooctanol 7.15
    dipropyl ether 4.75
    1,2-dichlorobenzene 2.53
    ethyl lactate 13.95
    propylene carbonate 20.27
    n-methylformamide 141.41
    2-pentanol 13.45
    n-pentane 0.73
    1-propoxy-2-propanol 26.7
    1-methoxy-2-propyl acetate 12.4
    2-(2-methoxypropoxy) propanol 30.38
    mesitylene 1.79
    ε-caprolactone 22.67
    p-cymene 2.28
    epichlorohydrin 34.91
    1,1,1-trichloroethane 2.49
    2-aminoethanol 114.43
    morpholine-4-carbaldehyde 127.4
    sulfolane 94.3
    2,2,4-trimethylpentane 0.44
    2-methyltetrahydrofuran 18.19
    n-hexyl acetate 8.99
    isooctane 0.32
    2-(2-butoxyethoxy)ethanol 36.16
    sec-butyl acetate 3.95
    tert-butyl acetate 7.49
    decalin 0.48
    glycerin 138.44
    diglyme 60.72
    acrylic acid 26.12
    isopropyl myristate 4.4
    n-butyric acid 24.23
    acetyl acetate 5.97
    di(2-ethylhexyl) phthalate 8.87
    ethyl propionate 6.65
    nitromethane 77.84
    1,2-diethoxyethane 10.69
    benzonitrile 8.18
    trioctyl phosphate 7.13
    1-bromopropane 2.94
    gamma-valerolactone 76.61
    n-decanol 7.07
    triethyl phosphate 6.05
    4-methyl-2-pentanol 7.71
    propionitrile 10.29
    vinylene carbonate 20.15
    1,1,2-trichlorotrifluoroethane 51.52
    DMS 7.1
    cumene 2.01
    2-octanol 6.45
    2-hexanone 10.86
    octyl acetate 6.51
    limonene 2.88
    1,2-dimethoxyethane 107.71
    ethyl orthosilicate 5.4
    tributyl phosphate 6.89
    diacetone alcohol 27.35
    N,N-dimethylaniline 10.57
    acrylonitrile 18.04
    aniline 5.42
    1,3-propanediol 99.12
    bromobenzene 1.06
    dibromomethane 2.78
    1,1,2,2-tetrachloroethane 7.12
    2-methyl-cyclohexyl acetate 7.17
    tetrabutyl urea 13.67
    diisobutyl methanol 4.43
    2-phenylethanol 11.24
    styrene 1.64
    dioctyl adipate 7.68
    dimethyl sulfate 34.04
    ethyl butyrate 6.37
    methyl lactate 29.3
    butyl lactate 12.29
    diethyl carbonate 4.83
    propanediol butyl ether 31.57
    triethyl orthoformate 5.91
    p-tert-butyltoluene 2.28
    methyl 4-tert-butylbenzoate 16.13
    morpholine 44.12
    tert-butylamine 14.65
    n-dodecanol 5.45
    dimethoxymethane 88.52
    ethylene carbonate 15.04
    cyrene 37.89
    2-ethoxyethyl acetate 9.45
    2-ethylhexyl acetate 4.89
    1,2,4-trichlorobenzene 3.16
    4-methylpyridine 12.84
    dibutyl ether 4.5
    2,6-dimethyl-4-heptanol 4.43
    DEF 42.87
    dimethyl isosorbide 35.77
    tetrachloroethylene 5.78
    eugenol 22.7
    triacetin 10.4
    span 80 20.7
    1,4-butanediol 53.76
    1,1-dichloroethane 3.07
    2-methyl-1-pentanol 15.96
    methyl formate 108.83
    2-methyl-1-butanol 22.02
    n-decane 0.7
    butyronitrile 13.83
    3,7-dimethyl-1-octanol 7.72
    1-chlorooctane 2.31
    1-chlorotetradecane 1.19
    n-nonane 0.65
    undecane 0.56
    tert-butylcyclohexane 0.51
    cyclooctane 0.27
    cyclopentanol 21.01
    tetrahydropyran 10.05
    tert-amyl methyl ether 9.24
    2,5,8-trioxanonane 50.99
    1-hexene 2.55
    2-isopropoxyethanol 36.05
    2,2,2-trifluoroethanol 33.7
    methyl butyrate 12.86

    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