Sodium Fluorescein

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  • Identifiers

    CAS number
    518-47-8

    Molecular formula
    C20H10Na2O5

    SMILES
    C1=CC=C(C(=C1)C2=C3C=CC(=O)C=C3OC4=C2C=CC(=C4)[O-])C(=O)[O-].[Na+].[Na+]

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 41.52%
    Phenolic 34.24%
    Sweet 34.19%
    Fruity 34.16%
    Powdery 30.92%
    Balsamic 29.29%
    Floral 28.21%
    Grape 26.83%
    Neroli 26.05%
    Honey 26.02%

     

    Flavor
    Bitter 92.92%
    Odorless 27.92%
    Nitrile 20.15%
    Very strong 19.83%
    Indole 19.27%
    Lovage 18.91%
    Sweet-like 18.81%
    Moth ball 18.76%
    Cedarleaf 18.61%
    Naphthelene 18.44%

     

    Odor impact est.
    Low

  • Properties

    pKa est.
    4.2 (weak acid)

    Molecular weight
    376.3 g/mol

    Melting point expt.

    • 599 to 743 °F (decomposes) (NTP, 1992)

    Flash point

    • 250.82 ˚C est.

    Solubility expt.

    • greater than or equal to 100 mg/mL at 68 °F (NTP, 1992)
    • Soluble in ethanol, glycerol, dilute acetone
    • Slightly soluble in alcohol
    • In water, 4.0X10+4 mg/L, temperature not specified

  • Synonyms

    • Fluorescein disodium salt
    • Soluble fluorescein
    • Sodium fluorescein
    • Uranin
    • Uranine WSS
    • Resorcinol phthalein sodium
    • Uranine Yellow
    • Ak-Fluor
    • Funduscein-25
    • Fluorescein, soluble
    • Ki202
    • Sodium fluoresceinate
    • Fluoresceinum natricum
    • 93X55PE38X
    • D&C Yellow No. 8
    • Ki202(1)
    • Ki202(2)
    • D & C Yellow no. 8
    • disodium 2-(6-oxido-3-oxo-3H-xanthen-9-yl)benzoate
    • CI 45350
    • CI 45350 (Na salt)
    • 3',6'-Dihydroxyspiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, disodium salt
    • Retinofluor
    • Glostrips
    • Bioglo
    • Fluor-amps
    • Dry Eye Test
    • Fluorescein, Sodium
    • Sodium, Fluorescein
    • Ak-fluor 10%
    • Ak-fluor 25%
    • RefChem:55213
    • C.I. 45350 Disodium salt
    • C20H10Na2O5 Fluorescein Sodium Ophthalmic Strips
    • 3',6'-Dihydroxyspiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one
    • 518-47-8
    • DTXCID905328
    • DTXSID9025328
    • Fluorescein Sodium
    • Fluorescein, disodium salt
    • C.I. Acid Yellow 73
    • C.I. 45350
    • disodium;2-(3-oxido-6-oxoxanthen-9-yl)benzoate
    • Aizen uranine
    • Calcocid uranine B4315
    • Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, 3',6'-dihydroxy-, sodium salt (1:2)
    • Spiro(isobenzofuran-1(3H),9'-(9H)xanthene)-3-one, 3'6'-dihydroxy, disodium salt
    • Funduscein
    • Flurenate
    • Furanium
    • Obiturine
    • Hidacid uranine
    • Fluorescein LT
    • Uranine A
    • Uranine O
    • Uranin A
    • Uranin S
    • Uranine A Extra
    • Uranine SS
    • Fluor-I-Strip
    • Yellow 8
    • Soluble fluoresceine
    • Floures (TN)
    • Certiqual fluoresceine
    • Fluorescein Free Acid
    • Basacid Yellow 226
    • Fluor-I-strip A.T.
    • Fluorescein sodium B.P
    • 11824 Yellow
    • 12417 Yellow
    • Soluble Fluoresceine BPS
    • Japan Yellow 202(1)
    • Acid yellow 73 sodium salt
    • SCHEMBL264060
    • UNII-93X55PE38X
    • CCRIS 6239
    • orb1690451
    • CHEMBL1628233
    • FLUORESCEIN SODIUM [JAN]
    • SCHEMBL29355465
    • SCHEMBL29364968
    • Fluorescein sodium (JP17/USP)
    • HSDB 8007
    • FLUORESCEIN SODIUM [VANDF]
    • MOLI001004
    • NCI-C54706
    • FLUORESCEIN SODIUM [MART.]
    • Fluorescein sodium [USP:BAN:JAN]
    • FLUORESCEIN SODIUM [WHO-DD]
    • FLUORESCEIN SODIUM [WHO-IP]
    • NSC 5070
    • EINECS 208-253-0
    • EBC-13035
    • MFCD00064308
    • AKOS024364966
    • FLUORESCEIN DISODIUM SALT [MI]
    • FF09633
    • FLUORESCEIN SODIUM [EP IMPURITY]
    • FLUORESCEIN SODIUM [ORANGE BOOK]
    • FLUORESCEIN SODIUM [EP MONOGRAPH]
    • AS-17142
    • DA-63481
    • FLUORESCEIN SODIUM [USP MONOGRAPH]
    • F0096
    • FLUORESCEINUM NATRICUM [WHO-IP LATIN]
    • EN300-73461
    • D02024
    • Disodium 6-hydroxy-3-oxo-9-xanthene-o-benzoate
    • Sodium salt of hydroxy-o-carboxy-phenyl-fluorone
    • disodium;2-(3-oxido-6-oxo-xanthen-9-yl)benzoate
    • Q27271622
    • Z1160865418
    • 9-o-Carboxyphenyl-6-hydroxy-3-isoxanthone, disodium salt
    • BENZOIC ACID, 2-(6-HYDROXY-3-OXO-3H-XANTHEN-9-YL)-, DISODIUM SALT
    • Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, 3',6'-dihydroxy-, disodium salt
    • 518-47-8

  • Applications

    Sodium Fluorescein (CAS 518-47-8) is used primarily as a tracer and fluorescent dye across multiple industries and analytical contexts. It is commonly employed to detect leaks and trace fluid flow in piping, cooling systems, and production processes by enabling localization and quantification through fluorescence. In biomedical and analytical settings, it serves as a fluorescent stain for diagnostic imaging and visualization of cells or tissues, as well as in fluorescence-based assays. In coatings and inks, it functions as a fluorescent colorant to facilitate quality control and UV-visible inspection. It can also be used as a fluorescence indicator in chemical analysis and as a water tracer for environmental studies or polymer processing. Use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 2.75
    methanol 2.48
    isopropanol 1.15
    water 0.01
    ethyl acetate 2.82
    n-propanol 1.89
    acetone 4.73
    n-butanol 1.5
    acetonitrile 1.75
    DMF 31.53
    toluene 2.03
    isobutanol 1.36
    1,4-dioxane 9.19
    methyl acetate 4.64
    THF 23.18
    2-butanone 7.52
    n-pentanol 1.31
    sec-butanol 1.54
    n-hexane 0.01
    ethylene glycol 3.85
    NMP 31.01
    cyclohexane 0.02
    DMSO 48.01
    n-butyl acetate 3.5
    n-octanol 1.01
    chloroform 0.53
    n-propyl acetate 3.33
    acetic acid 5.21
    dichloromethane 1.77
    cyclohexanone 11.11
    propylene glycol 2.52
    isopropyl acetate 2.51
    DMAc 51.62
    2-ethoxyethanol 8.85
    isopentanol 1.58
    n-heptane 0.02
    ethyl formate 2.79
    1,2-dichloroethane 2.76
    n-hexanol 1.23
    2-methoxyethanol 19.97
    isobutyl acetate 1.68
    tetrachloromethane 0.08
    n-pentyl acetate 3.33
    transcutol 34.73
    n-heptanol 1.5
    ethylbenzene 1.18
    MIBK 2.64
    2-propoxyethanol 11.96
    tert-butanol 1.23
    MTBE 0.86
    2-butoxyethanol 8.15
    propionic acid 4.54
    o-xylene 1.54
    formic acid 5.78
    diethyl ether 0.99
    m-xylene 1.08
    p-xylene 1.2
    chlorobenzene 1.36
    dimethyl carbonate 6.16
    n-octane 0.01
    formamide 14.02
    cyclopentanone 17.04
    2-pentanone 3.93
    anisole 4.28
    cyclopentyl methyl ether 3.69
    gamma-butyrolactone 18.47
    1-methoxy-2-propanol 11.66
    pyridine 13.51
    3-pentanone 3.34
    furfural 16.82
    n-dodecane 0.04
    diethylene glycol 16.21
    diisopropyl ether 0.28
    tert-amyl alcohol 1.74
    acetylacetone 7.37
    n-hexadecane 0.04
    acetophenone 7.06
    methyl propionate 5.32
    isopentyl acetate 3.49
    trichloroethylene 5.34
    n-nonanol 1.33
    cyclohexanol 2.17
    benzyl alcohol 6.11
    2-ethylhexanol 1.23
    isooctanol 1.44
    dipropyl ether 1.34
    1,2-dichlorobenzene 1.54
    ethyl lactate 5.15
    propylene carbonate 6.39
    n-methylformamide 11.51
    2-pentanol 0.82
    n-pentane 0.01
    1-propoxy-2-propanol 8.21
    1-methoxy-2-propyl acetate 9.47
    2-(2-methoxypropoxy) propanol 11.82
    mesitylene 0.52
    ε-caprolactone 11.29
    p-cymene 1.04
    epichlorohydrin 22.63
    1,1,1-trichloroethane 0.49
    2-aminoethanol 4.57
    morpholine-4-carbaldehyde 32.81
    sulfolane 32.87
    2,2,4-trimethylpentane 0.02
    2-methyltetrahydrofuran 6.63
    n-hexyl acetate 3.52
    isooctane 0.01
    2-(2-butoxyethoxy)ethanol 13.54
    sec-butyl acetate 2.47
    tert-butyl acetate 3.04
    decalin 0.04
    glycerin 9.31
    diglyme 23.9
    acrylic acid 6.19
    isopropyl myristate 1.94
    n-butyric acid 3.65
    acetyl acetate 2.41
    di(2-ethylhexyl) phthalate 3.68
    ethyl propionate 3.57
    nitromethane 9.78
    1,2-diethoxyethane 6.62
    benzonitrile 4.52
    trioctyl phosphate 2.11
    1-bromopropane 0.64
    gamma-valerolactone 27.91
    n-decanol 1.09
    triethyl phosphate 3.44
    4-methyl-2-pentanol 0.71
    propionitrile 2.48
    vinylene carbonate 6.37
    1,1,2-trichlorotrifluoroethane 19.07
    DMS 7.4
    cumene 0.77
    2-octanol 0.85
    2-hexanone 3.9
    octyl acetate 2.54
    limonene 1.08
    1,2-dimethoxyethane 15.45
    ethyl orthosilicate 2.87
    tributyl phosphate 2.64
    diacetone alcohol 7.72
    N,N-dimethylaniline 3.33
    acrylonitrile 5.58
    aniline 5.64
    1,3-propanediol 6.27
    bromobenzene 1.03
    dibromomethane 0.64
    1,1,2,2-tetrachloroethane 3.77
    2-methyl-cyclohexyl acetate 3.86
    tetrabutyl urea 4.54
    diisobutyl methanol 0.91
    2-phenylethanol 5.94
    styrene 1.36
    dioctyl adipate 4.28
    dimethyl sulfate 14.05
    ethyl butyrate 3.34
    methyl lactate 9.59
    butyl lactate 5.71
    diethyl carbonate 2.9
    propanediol butyl ether 6.53
    triethyl orthoformate 3.48
    p-tert-butyltoluene 0.82
    methyl 4-tert-butylbenzoate 8.13
    morpholine 14.15
    tert-butylamine 0.42
    n-dodecanol 0.87
    dimethoxymethane 13.38
    ethylene carbonate 4.84
    cyrene 12.52
    2-ethoxyethyl acetate 8.19
    2-ethylhexyl acetate 2.92
    1,2,4-trichlorobenzene 2.84
    4-methylpyridine 9.59
    dibutyl ether 1.48
    2,6-dimethyl-4-heptanol 0.91
    DEF 9.82
    dimethyl isosorbide 18.97
    tetrachloroethylene 2.5
    eugenol 10.17
    triacetin 7.62
    span 80 7.27
    1,4-butanediol 2.39
    1,1-dichloroethane 0.59
    2-methyl-1-pentanol 1.83
    methyl formate 7.21
    2-methyl-1-butanol 1.84
    n-decane 0.04
    butyronitrile 1.9
    3,7-dimethyl-1-octanol 1.26
    1-chlorooctane 0.4
    1-chlorotetradecane 0.26
    n-nonane 0.02
    undecane 0.04
    tert-butylcyclohexane 0.03
    cyclooctane 0.01
    cyclopentanol 2.73
    tetrahydropyran 4.14
    tert-amyl methyl ether 1.27
    2,5,8-trioxanonane 19.04
    1-hexene 0.1
    2-isopropoxyethanol 6.05
    2,2,2-trifluoroethanol 3.19
    methyl butyrate 4.5

    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