Phenol Red

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  • Identifiers

    CAS number
    143-74-8

    Molecular formula
    C19H14O5S

    SMILES
    C1=CC=C2C(=C1)C(OS2(=O)=O)(C3=CC=C(C=C3)O)C4=CC=C(C=C4)O

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 60.57%
    Phenolic 43.24%
    Bitter 29.46%
    Burnt 24.66%
    Medicinal 23.56%
    Nutty 22.23%
    Balsamic 22.02%
    Spicy 20.61%
    Aromatic 20.45%
    Sweet 19.39%

     

    Flavor
    Bitter 92.19%
    Very strong 20.37%
    Nitrile 20.28%
    Indole 20.09%
    Cedarleaf 19.48%
    Lovage 19.4%
    Moth ball 19.4%
    Naphthelene 18.86%
    Sweet-like 18.5%
    Bread crust 18.29%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    3.0

    pKa est.
    8.19 (weak base)

    Molecular weight
    354.4 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    608°C

    Flash point

    • 254.05 ˚C est.

  • Synonyms

    • PHENOL RED
    • phenolsulfonphthalein
    • 143-74-8
    • Fenolipuna
    • Sulphonthal
    • Phenolsulphonphthalein
    • PSP (indicator)
    • NSC-10459
    • DTXSID8022408
    • I6G9Y0J1OJ
    • DTXCID202408
    • CHEBI:31991
    • Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis-, (S,S-dioxide)
    • 3,3-bis(4-hydroxyphenyl)-3H-2,1??-benzoxathiole-1,1-dione
    • RefChem:172881
    • 2-(Bis(4-hydroxyphenyl)methyliumyl)benzenesulfonate
    • 205-609-7
    • Sulfonphthal
    • Sulphental
    • 3,3-Bis(4-hydroxyphenyl)-3H-benzo[c][1,2]oxathiole 1,1-dioxide
    • Phenolsulfonephthalein
    • Phenol, 4,4'-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis-
    • MFCD00003552
    • Phenol red solution
    • NSC10459
    • NSC 10459
    • C19H14O5S
    • 4-[3-(4-Hydroxyphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]phenol
    • 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)diphenol S,S-dioxide
    • 4,4'-(1,1-dioxido-3H-2,1-benzoxathiole-3,3-diyl)diphenol
    • 3H-2,1-Benzoxathiole, 3,3-bis(4-hydroxyphenyl)-, 1,1-dioxide
    • Phenol, 4,4-(3H-2,1-benzoxathiol-3-ylidene)di-, S-S-dioxide
    • P. S. P.
    • NCGC00013109-03
    • Phenolred
    • Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide
    • 3,3-bis(4-hydroxyphenyl)benzo[c]1,2-oxathiolene-1,1-dione
    • 3,3-bis(p-hydroxyphenyl)-3H-2,1-benzoxathiole 1,1-dioxide
    • Phenol-red
    • CAS-143-74-8
    • EINECS 205-609-7
    • UNII-I6G9Y0J1OJ
    • BRN 0326470
    • Phenolsulfonphthalein [JAN:NF]
    • Phenosulfophthalein
    • Phenolsulfonphthalein; 3,3-bis(4-hydroxyphenyl)-3H-2,1-benzoxathiole 1,1-dioxide; PSP
    • Phenol red, PSP
    • Phenol red indicator
    • phenolsulphonephthalein
    • Phenol red ACS grade
    • Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis-, S,S-dioxide
    • Phenol Red, ACS reagent
    • Phenol Red (>90%)
    • Phenol red, recrystallized
    • NCIStruc1_001090
    • NCIStruc2_000839
    • SCHEMBL17836
    • 5-19-03-00457 (Beilstein Handbook Reference)
    • BIDD:ER0046
    • CHEMBL258921
    • orb1310700
    • Phenol Red, JIS special grade
    • SCHEMBL6933711
    • SCHEMBL29357178
    • Phenol Red, p.a., ACS reagent
    • Phenolsulfonphthalein (JP18/NF)
    • PHENOLSULFONPHTHALEIN [MI]
    • PHENOLSULFONPHTHALEIN [JAN]
    • 3,3-bis(4-hydroxyphenyl)-3H-2,1lambda6-benzoxathiole-1,1-dione
    • HY-D0169
    • NCI10459
    • PHENOLSULFONPHTHALEIN [VANDF]
    • Tox21_110012
    • Tox21_303570
    • BBL000596
    • CCG-36909
    • EBC-03857
    • NCGC00013109
    • PHENOLSULFONPHTHALEIN [MART.]
    • SBB006473
    • STK364540
    • PHENOLSULFONPHTHALEIN [WHO-DD]
    • 4-[3-(4-hydroxyphenyl)-1,1-dioxo-2,1$l^{6}-benzoxathiol-3-yl]phenol
    • AKOS000592531
    • Tox21_110012_1
    • DB13212
    • NCGC00013109-01
    • NCGC00013109-02
    • NCGC00096230-01
    • NCGC00257424-01
    • AC-18338
    • NCI60_000111
    • ST057659
    • SY010293
    • VS-00652
    • DB-042702
    • PHENOLSULFONPHTHALEIN [EP MONOGRAPH]
    • CS-0010076
    • NS00019704
    • P0100
    • P0101
    • P0703
    • D01200
    • D70382
    • P-2800
    • P-2801
    • AB00444024_03
    • EN300-6492950
    • F600656
    • Q418719
    • SR-01000357546
    • 3H-2, 3,3-bis(4-hydroxyphenyl)-, 1,1-dioxide
    • SR-01000357546-1
    • BRD-K79892937-001-01-7
    • BRD-K79892937-001-02-5
    • Phenol red solution (liquid, 0.5%, sterile-filtered)
    • Z56768517
    • Phenol Red, powder, BioReagent, suitable for cell culture
    • 4,4'-(3H,2,1-Benzoxathiol-3-ylidene)bisphenol S,S-dioxide
    • 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bisphenol S,S-dioxide
    • 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)diphenol, S,S-dioxide-
    • Phenol,4'-(3H-2,1-benzoxathiol-3-ylidene)bis-, S,S-dioxide
    • Phenol,4'-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide
    • Phenol,4-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide
    • Phenol,4-(3H-2,1-benzoxathiol-3-ylidene)di-, S-S-dioxide
    • 3,3-BIS(4-HYDROXYPHENYL)-3H-2,1-BENZOXATHIOLE 1,1-DIOXIDE
    • 3,3-Bis(4-hydroxyphenyl)-2,1lambda~6~-benzoxathiole-1,1(3H)-dione
    • 143-74-8

  • Applications

    Phenol Red (CAS 143-74-8) is a commonly used pH indicator dye in laboratory settings. In biology and biochemistry, it is widely employed as the pH indicator in cell culture media and microbial growth media, enabling visual monitoring of pH changes during incubation. It also serves as a colorimetric indicator in analytical chemistry and titration procedures, and is frequently used in educational demonstrations to illustrate acid-base concepts. Its role as a pH indicator dye is subject to formulation limits and local regulations.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.37
    methanol 0.9
    isopropanol 0.17
    water 0.68
    ethyl acetate 0.23
    n-propanol 0.21
    acetone 1.65
    n-butanol 0.18
    acetonitrile 0.7
    DMF 68.13
    toluene 0.18
    isobutanol 0.12
    1,4-dioxane 2.48
    methyl acetate 0.24
    THF 9.25
    2-butanone 0.76
    n-pentanol 0.26
    sec-butanol 0.15
    n-hexane 0.0
    ethylene glycol 2.31
    NMP 21.69
    cyclohexane 0.01
    DMSO 15.32
    n-butyl acetate 1.9
    n-octanol 2.62
    chloroform 0.61
    n-propyl acetate 0.86
    acetic acid 1.82
    dichloromethane 0.51
    cyclohexanone 3.94
    propylene glycol 1.17
    isopropyl acetate 0.64
    DMAc 26.54
    2-ethoxyethanol 2.93
    isopentanol 0.27
    n-heptane 0.02
    ethyl formate 0.87
    1,2-dichloroethane 0.44
    n-hexanol 0.67
    2-methoxyethanol 7.31
    isobutyl acetate 1.04
    tetrachloromethane 0.06
    n-pentyl acetate 4.17
    transcutol 17.13
    n-heptanol 2.25
    ethylbenzene 0.2
    MIBK 1.34
    2-propoxyethanol 9.2
    tert-butanol 0.38
    MTBE 0.17
    2-butoxyethanol 10.65
    propionic acid 0.62
    o-xylene 0.24
    formic acid 4.7
    diethyl ether 0.11
    m-xylene 0.25
    p-xylene 0.32
    chlorobenzene 0.57
    dimethyl carbonate 2.35
    n-octane 0.03
    formamide 11.05
    cyclopentanone 8.81
    2-pentanone 0.79
    anisole 1.53
    cyclopentyl methyl ether 0.79
    gamma-butyrolactone 7.8
    1-methoxy-2-propanol 5.37
    pyridine 2.84
    3-pentanone 0.49
    furfural 13.64
    n-dodecane 0.1
    diethylene glycol 13.86
    diisopropyl ether 0.09
    tert-amyl alcohol 0.29
    acetylacetone 4.21
    n-hexadecane 0.11
    acetophenone 4.1
    methyl propionate 0.49
    isopentyl acetate 2.92
    trichloroethylene 1.87
    n-nonanol 3.1
    cyclohexanol 0.34
    benzyl alcohol 2.32
    2-ethylhexanol 0.78
    isooctanol 2.11
    dipropyl ether 0.65
    1,2-dichlorobenzene 1.07
    ethyl lactate 3.46
    propylene carbonate 5.07
    n-methylformamide 6.74
    2-pentanol 0.12
    n-pentane 0.0
    1-propoxy-2-propanol 7.22
    1-methoxy-2-propyl acetate 6.87
    2-(2-methoxypropoxy) propanol 13.99
    mesitylene 0.25
    ε-caprolactone 3.11
    p-cymene 0.8
    epichlorohydrin 5.35
    1,1,1-trichloroethane 0.24
    2-aminoethanol 1.85
    morpholine-4-carbaldehyde 28.46
    sulfolane 19.6
    2,2,4-trimethylpentane 0.01
    2-methyltetrahydrofuran 0.87
    n-hexyl acetate 4.68
    isooctane 0.01
    2-(2-butoxyethoxy)ethanol 14.72
    sec-butyl acetate 0.7
    tert-butyl acetate 1.75
    decalin 0.02
    glycerin 7.69
    diglyme 21.53
    acrylic acid 1.78
    isopropyl myristate 3.44
    n-butyric acid 0.82
    acetyl acetate 0.96
    di(2-ethylhexyl) phthalate 6.76
    ethyl propionate 0.69
    nitromethane 5.28
    1,2-diethoxyethane 3.92
    benzonitrile 4.14
    trioctyl phosphate 5.14
    1-bromopropane 0.07
    gamma-valerolactone 20.93
    n-decanol 2.38
    triethyl phosphate 2.97
    4-methyl-2-pentanol 0.27
    propionitrile 0.76
    vinylene carbonate 5.52
    1,1,2-trichlorotrifluoroethane 12.1
    DMS 4.48
    cumene 0.26
    2-octanol 1.53
    2-hexanone 1.31
    octyl acetate 4.22
    limonene 0.66
    1,2-dimethoxyethane 7.2
    ethyl orthosilicate 2.63
    tributyl phosphate 4.41
    diacetone alcohol 4.8
    N,N-dimethylaniline 2.0
    acrylonitrile 2.4
    aniline 0.78
    1,3-propanediol 1.79
    bromobenzene 0.43
    dibromomethane 0.2
    1,1,2,2-tetrachloroethane 1.52
    2-methyl-cyclohexyl acetate 4.22
    tetrabutyl urea 9.39
    diisobutyl methanol 0.93
    2-phenylethanol 4.87
    styrene 0.24
    dioctyl adipate 6.42
    dimethyl sulfate 6.74
    ethyl butyrate 1.86
    methyl lactate 4.59
    butyl lactate 8.7
    diethyl carbonate 2.04
    propanediol butyl ether 11.56
    triethyl orthoformate 3.2
    p-tert-butyltoluene 0.74
    methyl 4-tert-butylbenzoate 12.2
    morpholine 2.75
    tert-butylamine 0.13
    n-dodecanol 1.84
    dimethoxymethane 7.09
    ethylene carbonate 3.51
    cyrene 16.63
    2-ethoxyethyl acetate 6.18
    2-ethylhexyl acetate 2.26
    1,2,4-trichlorobenzene 1.66
    4-methylpyridine 1.81
    dibutyl ether 1.35
    2,6-dimethyl-4-heptanol 0.93
    DEF 2.52
    dimethyl isosorbide 24.97
    tetrachloroethylene 0.97
    eugenol 16.87
    triacetin 9.08
    span 80 11.52
    1,4-butanediol 0.96
    1,1-dichloroethane 0.14
    2-methyl-1-pentanol 0.34
    methyl formate 4.52
    2-methyl-1-butanol 0.18
    n-decane 0.12
    butyronitrile 0.72
    3,7-dimethyl-1-octanol 2.1
    1-chlorooctane 0.68
    1-chlorotetradecane 0.47
    n-nonane 0.07
    undecane 0.1
    tert-butylcyclohexane 0.02
    cyclooctane 0.01
    cyclopentanol 0.56
    tetrahydropyran 0.53
    tert-amyl methyl ether 0.24
    2,5,8-trioxanonane 22.81
    1-hexene 0.02
    2-isopropoxyethanol 2.07
    2,2,2-trifluoroethanol 2.11
    methyl butyrate 1.12

    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