5-Chloro-2-methyl-4-isothiazolin-3-one

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  • Identifiers

    CAS number
    26172-55-4

    Molecular formula
    C4H4ClNOS

    SMILES
    CN1C(=O)C=C(S1)Cl

    Safety labels

    Corrosive
    Corrosive

    Acute Toxic
    Acute Toxic

    Irritant
    Irritant

    Environmental Hazard
    Environmental

  • Odor profile

    Fragrance
    Meaty 49.77%
    Odorless 47.78%
    Roasted 47.76%
    Sulfurous 38.34%
    Nutty 32.58%
    Cooked 32.18%
    Savory 29.82%
    Burnt 29.73%
    Beefy 24.96%
    Coffee 20.89%

     

    Flavor
    Bitter 44.65%
    Nutty 33.83%
    Roasted 30.84%
    Odorless 29.04%
    Coffee 24.92%
    Mild 23.97%
    Cocoa 23.94%
    Popcorn 23.36%
    Roast 23.2%
    Bread crust 22.9%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    0.9

    pKa est.
    4.51 (weak acid)

    Molecular weight
    149.6 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately fast

    Boiling point est.
    207°C

    Melting point expt.

    • 54-55 °C

    Flash point

    • 70.64 ˚C est.

    Solubility expt.

    • Solubility in g/100 mL solvent: water, infinite
    • In water, 706-751 g/L at 20 °C
    • Solubility in g/100 mL solvent: ethyl acetate, 4.31; methanol, 4.40, toluene, 4.07; hexane, 0.28
    • In ethyl acetate, 38.06 g/L at 10 °C

  • Synonyms

    • 5-Chloro-2-methyl-4-isothiazolin-3-one
    • 26172-55-4
    • Methylchloroisothiazolinone
    • CMIT
    • 5-Chloro-2-methyl-3(2H)-isothiazolone
    • 5-Chloro-2-methyl-3-isothiazolone
    • Kathon CG 5243
    • 3(2H)-Isothiazolone, 5-chloro-2-methyl-
    • 5-chloro-N-methylisothiazolone
    • 5-chloro-2-methylisothiazolin-3-one
    • 5-chloro-n-methylisothiazolin-3-one
    • HS 818
    • n-methyl-5-chloroisothiazolone
    • DEL7T5QRPN
    • 4-ISOTHIAZOLIN-3-ONE, 5-CHLORO-2-METHYL-
    • N-Methyl-5-chloroisothiazolin-3-one
    • DTXSID9034286
    • 5-chloro-2-methyl-3(2H)-isothiazolinone
    • DTXCID7014286
    • HS-818
    • RefChem:818544
    • 247-500-7
    • Chloromethylisothiazolinone
    • 5-chloro-2-methylisothiazol-3(2h)-one
    • 5-Chloro-2-methyl-2H-isothiazol-3-one
    • MFCD00792550
    • 5-chloro-2-methyl-1,2-thiazol-3-one
    • 5-chloro-2-methyl-isothiazol-3-one
    • 5-chloro-2-methyl-4-isothiazoline-3-one
    • 5-chloro-2-methyl-1,2-thiazol-3(2H)-one
    • 2,3-Dihydro-2-methyl-3-oxo-5-chloroisothiazole
    • 5-chloro-2-methyl-2,3-dihydro-1,2-thiazol-3-one
    • 5-Chloro-2-methyl-4-isothiazolin-3-one, tech grade, >14% in water. CMI/MI >2.0
    • NCGC00181041-01
    • Bioace
    • 5-Chloro-2-methyl-3-isothiazolone (~90%)
    • Kathon IXE
    • 5-Chloro-2-methyl-4-isothiazolin-3-one 100 microg/mL in Acetonitrile
    • N-Methyl-5-chloroisothiazolone (5-Chloro-2-methyl-4-isothiazolin-3-one)
    • CAS-26172-55-4
    • A 33 (bactericide)
    • UNII-DEL7T5QRPN
    • HS 818 (antiseptic)
    • EINECS 247-500-7
    • BRN 1210149
    • Isothiazolinones
    • 5-Chloro-2-methyl-4-isothiazolin-3-one D3 (methyl D3)
    • 5-Chloro-2-methyl-4-isothiazolin-3-one (CMI)
    • 2-Methyl-5-chloro-3-isothiazolone
    • 2-Methyl-5-chloroisothiazolin-3-one
    • 5-chloro-2-methyl-2h-isothiazolin-3-one
    • T 360
    • SCHEMBL20686
    • CHEMBL1738962
    • CHEBI:53621
    • HSDB 8270
    • MSK2157
    • EDC61134
    • Tox21_112689
    • Tox21_300199
    • EBC-26096
    • AKOS006230760
    • CS-W022348
    • DB14197
    • FC20025
    • GS-3223
    • HY-W041608
    • METHYLCHLOROISOTHIAZOLINONE [II]
    • METHYLCHLOROISOTHIAZOLINONE [MI]
    • 5-Chloro-2-methyl-4-isothiazol-3-one
    • 5-CHLORO-2-METHYL-4-ISOTHIAZOLIN-3-ONE (ACTIVE INGREDIENT >14%, CMI/MI 2.5 - 4.0)
    • NCGC00181041-02
    • NCGC00254127-01
    • METHYLCHLOROISOTHIAZOLINONE [VANDF]
    • 5-Chloro-2-methyl-isothiazol-3(2H)-one
    • METHYLCHLOROISOTHIAZOLINONE [MART.]
    • DB-007017
    • METHYLCHLOROISOTHIAZOLINONE [WHO-DD]
    • NS00000256
    • 5-CHLOR-2-METHYL-4-ISOTHIAZOLIN-3-ONE
    • H10371
    • SBI-0654074.0001
    • EN300-7409393
    • F209044
    • Q204121
    • SR-01000944864
    • SR-01000944864-1
    • Z2417817741
    • 5-Chloro-2-methyl-4-isothiazolin-3-one (CMI/MI > 2.0)
    • 5-Chloro-2-methyl-3-isothiazolone - Active Ingredient >14%, CMI/MI 2.5 - 4.0
    • 26172-55-4

  • Applications

    5-Chloro-2-methyl-4-isothiazolin-3-one (CAS 26172-55-4) is commonly used as a preservative and antimicrobial agent in cosmetics and personal care products. It is also used in household cleaning formulations as a preservative and biocide. In industrial manufacturing, the compound serves as a biocide for cooling water systems and metalworking fluids, and it is used in paints, coatings, and inks to control microbial growth. Additionally, it may be used as a preservative/biocide in polymer emulsions, plastics, and related adhesive systems to extend shelf life and maintain formulation stability.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 133.18
    methanol 175.17
    isopropanol 113.16
    water 52.61
    ethyl acetate 117.41
    n-propanol 100.25
    acetone 248.31
    n-butanol 97.93
    acetonitrile 166.23
    DMF 565.15
    toluene 67.3
    isobutanol 87.58
    1,4-dioxane 234.49
    methyl acetate 165.82
    THF 265.61
    2-butanone 157.89
    n-pentanol 83.21
    sec-butanol 106.29
    n-hexane 5.5
    ethylene glycol 96.14
    NMP 494.2
    cyclohexane 7.4
    DMSO 320.3
    n-butyl acetate 63.87
    n-octanol 52.18
    chloroform 267.67
    n-propyl acetate 87.4
    acetic acid 188.16
    dichloromethane 245.08
    cyclohexanone 190.0
    propylene glycol 78.95
    isopropyl acetate 84.94
    DMAc 534.2
    2-ethoxyethanol 201.78
    isopentanol 90.44
    n-heptane 7.8
    ethyl formate 116.05
    1,2-dichloroethane 129.44
    n-hexanol 62.04
    2-methoxyethanol 316.05
    isobutyl acetate 60.16
    tetrachloromethane 56.46
    n-pentyl acetate 58.21
    transcutol 250.33
    n-heptanol 51.33
    ethylbenzene 36.26
    MIBK 92.18
    2-propoxyethanol 147.89
    tert-butanol 141.38
    MTBE 110.99
    2-butoxyethanol 105.65
    propionic acid 94.27
    o-xylene 64.09
    formic acid 190.22
    diethyl ether 102.0
    m-xylene 56.0
    p-xylene 63.71
    chlorobenzene 88.05
    dimethyl carbonate 111.78
    n-octane 4.72
    formamide 289.97
    cyclopentanone 235.62
    2-pentanone 131.17
    anisole 136.04
    cyclopentyl methyl ether 136.74
    gamma-butyrolactone 245.81
    1-methoxy-2-propanol 230.95
    pyridine 182.81
    3-pentanone 105.33
    furfural 343.82
    n-dodecane 4.77
    diethylene glycol 165.24
    diisopropyl ether 37.14
    tert-amyl alcohol 132.57
    acetylacetone 183.5
    n-hexadecane 5.38
    acetophenone 141.03
    methyl propionate 118.66
    isopentyl acetate 63.15
    trichloroethylene 315.02
    n-nonanol 48.83
    cyclohexanol 104.77
    benzyl alcohol 114.13
    2-ethylhexanol 46.4
    isooctanol 47.98
    dipropyl ether 46.38
    1,2-dichlorobenzene 97.47
    ethyl lactate 67.57
    propylene carbonate 153.53
    n-methylformamide 235.95
    2-pentanol 82.7
    n-pentane 8.44
    1-propoxy-2-propanol 98.41
    1-methoxy-2-propyl acetate 93.89
    2-(2-methoxypropoxy) propanol 103.53
    mesitylene 35.62
    ε-caprolactone 155.14
    p-cymene 31.18
    epichlorohydrin 271.31
    1,1,1-trichloroethane 158.98
    2-aminoethanol 118.71
    morpholine-4-carbaldehyde 416.58
    sulfolane 282.44
    2,2,4-trimethylpentane 8.14
    2-methyltetrahydrofuran 183.75
    n-hexyl acetate 76.01
    isooctane 5.43
    2-(2-butoxyethoxy)ethanol 127.07
    sec-butyl acetate 64.11
    tert-butyl acetate 98.63
    decalin 7.85
    glycerin 145.07
    diglyme 240.55
    acrylic acid 107.92
    isopropyl myristate 38.77
    n-butyric acid 109.39
    acetyl acetate 98.94
    di(2-ethylhexyl) phthalate 45.2
    ethyl propionate 77.82
    nitromethane 430.28
    1,2-diethoxyethane 87.39
    benzonitrile 121.35
    trioctyl phosphate 33.75
    1-bromopropane 68.26
    gamma-valerolactone 339.54
    n-decanol 37.86
    triethyl phosphate 49.22
    4-methyl-2-pentanol 54.62
    propionitrile 90.3
    vinylene carbonate 156.99
    1,1,2-trichlorotrifluoroethane 264.53
    DMS 80.0
    cumene 31.45
    2-octanol 43.5
    2-hexanone 98.23
    octyl acetate 48.28
    limonene 42.97
    1,2-dimethoxyethane 264.91
    ethyl orthosilicate 47.03
    tributyl phosphate 38.1
    diacetone alcohol 141.61
    N,N-dimethylaniline 115.48
    acrylonitrile 132.3
    aniline 118.41
    1,3-propanediol 147.1
    bromobenzene 76.75
    dibromomethane 130.3
    1,1,2,2-tetrachloroethane 228.19
    2-methyl-cyclohexyl acetate 62.76
    tetrabutyl urea 55.64
    diisobutyl methanol 31.9
    2-phenylethanol 88.27
    styrene 47.73
    dioctyl adipate 55.17
    dimethyl sulfate 199.03
    ethyl butyrate 62.97
    methyl lactate 105.88
    butyl lactate 58.53
    diethyl carbonate 52.7
    propanediol butyl ether 99.29
    triethyl orthoformate 54.73
    p-tert-butyltoluene 31.41
    methyl 4-tert-butylbenzoate 103.28
    morpholine 247.58
    tert-butylamine 81.66
    n-dodecanol 29.99
    dimethoxymethane 276.02
    ethylene carbonate 117.37
    cyrene 152.69
    2-ethoxyethyl acetate 89.51
    2-ethylhexyl acetate 53.38
    1,2,4-trichlorobenzene 130.88
    4-methylpyridine 227.83
    dibutyl ether 42.89
    2,6-dimethyl-4-heptanol 31.9
    DEF 188.5
    dimethyl isosorbide 159.94
    tetrachloroethylene 157.88
    eugenol 114.28
    triacetin 99.36
    span 80 84.78
    1,4-butanediol 83.45
    1,1-dichloroethane 150.79
    2-methyl-1-pentanol 82.13
    methyl formate 217.52
    2-methyl-1-butanol 90.87
    n-decane 7.35
    butyronitrile 100.17
    3,7-dimethyl-1-octanol 52.18
    1-chlorooctane 30.4
    1-chlorotetradecane 13.76
    n-nonane 6.7
    undecane 5.71
    tert-butylcyclohexane 8.42
    cyclooctane 3.66
    cyclopentanol 115.59
    tetrahydropyran 137.27
    tert-amyl methyl ether 101.04
    2,5,8-trioxanonane 177.98
    1-hexene 24.83
    2-isopropoxyethanol 133.55
    2,2,2-trifluoroethanol 172.75
    methyl butyrate 107.26

    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