Selenious Acid

Overview IFRA Request a quote

  • Identifiers

    CAS number
    7783-00-8

    Molecular formula
    H2O3Se

    SMILES
    O[Se](=O)O

    Safety labels

    Acute Toxic
    Acute Toxic

    Health Hazard
    Health

    Environmental Hazard
    Environmental

  • Odor profile

    Fragrance
    Odorless 80.62%
    Sour 42.65%
    Sharp 29.64%
    Pungent 22.52%
    Cheesy 21.02%
    Sweaty 18.29%
    Clean 16.13%
    Burnt 14.65%
    Ethereal 13.4%
    Milky 13.29%

     

  • Properties

    pKa est.
    3.54 (weak acid)

    Molecular weight
    128.99 g/mol

    Melting point expt.

    • Decomposes at 158 °F (EPA, 1998)
    • 70 undefined
    • 70 °C with decomposition.

    Boiling point

    • 684.9 undefined

    Flash point

    • 143.6 ˚C est.

    Solubility expt.

    • soluble
    • 90 parts/100 parts water @ 0 °C; 400 parts @ 90 °C
    • Very sol in alcohol; insol in ammonia
    • 167 g/100 cc water @ 20 °C
    • Solubility in water, g/100ml at 20 °C: 167

  • Synonyms

    • SELENIOUS ACID
    • Selenous acid
    • 7783-00-8
    • Monohydrated selenium dioxide
    • Selenium dioxide, monohydrated
    • Selenious acid (H2SeO3)
    • CCRIS 5530
    • selenige Saeure
    • HSDB 6065
    • EINECS 231-974-7
    • UNII-F6A27P4Q4R
    • UN-3283
    • F6A27P4Q4R
    • DTXSID9024300
    • CHEBI:26642
    • dihydroxidooxidoselenium
    • Selenious acid (USP)
    • Selenious acid [USP]
    • UN 3283
    • Selenium (as selenious acid)
    • DTXCID004300
    • EC 231-974-7
    • MFCD00011331
    • (SeO(OH)2)
    • [SeO(OH)2]
    • SELENIOUS ACID (MART.)
    • SELENIOUS ACID [MART.]
    • acide selenieux
    • Acid, Selenous
    • SELENIOUS ACID (USP MONOGRAPH)
    • SELENIOUS ACID [USP MONOGRAPH]
    • Acido selenioso
    • Acido selenio
    • selenige Saure
    • Selenous acid, 98%
    • Selenious acid(H2SeO3)
    • NCIMech_000026
    • SELENIOUS ACID [MI]
    • SELENIOUS ACID [HSDB]
    • SELENIOUS ACID [VANDF]
    • CHEMBL2009089
    • SELENIOUS ACID [WHO-DD]
    • Selenous acid, p.a., 95.0%
    • Selenous acid (99.999%-Se)
    • Tox21_200407
    • CCG-35433
    • SELENIOUS ACID [ORANGE BOOK]
    • AKOS015960374
    • DB11127
    • NCGC00248596-01
    • NCGC00257961-01
    • NCI60_003085
    • CAS-7783-00-8
    • NS00080941
    • Selenous acid, 99.999% trace metals basis
    • SELENIUM (AS SELENIOUS ACID) [VANDF]
    • D05814
    • Q413722
    • 231-974-7

  • Applications

    Selenious acid (H2SeO3, CAS 7783-00-8) is primarily used as a precursor to selenium(IV) salts such as selenites and selenates for industrial pigments, glass coloration, and ceramic glazes. It also serves as a source of Se(IV) in chemical synthesis and materials manufacturing. In organic chemistry, it acts as a mild oxidizing agent for selective oxidations and as an intermediate in the synthesis of organic selenium compounds. In analytical chemistry, it is employed as a reagent for selenium determination and related formulations. Depending on process conditions and local regulations, it may also be encountered in water treatment or material processing applications.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 291.58
    methanol 540.99
    isopropanol 228.33
    water 826.01
    ethyl acetate 42.6
    n-propanol 176.8
    acetone 318.36
    n-butanol 116.92
    acetonitrile 137.17
    DMF 1131.96
    toluene 13.84
    isobutanol 112.48
    1,4-dioxane 175.94
    methyl acetate 80.64
    THF 312.38
    2-butanone 102.69
    n-pentanol 85.0
    sec-butanol 109.72
    n-hexane 11.88
    ethylene glycol 436.4
    NMP 412.46
    cyclohexane 15.88
    DMSO 1063.9
    n-butyl acetate 36.15
    n-octanol 43.96
    chloroform 20.69
    n-propyl acetate 42.8
    acetic acid 208.33
    dichloromethane 32.73
    cyclohexanone 83.38
    propylene glycol 256.94
    isopropyl acetate 32.79
    DMAc 538.48
    2-ethoxyethanol 237.53
    isopentanol 79.31
    n-heptane 13.73
    ethyl formate 80.32
    1,2-dichloroethane 43.9
    n-hexanol 64.65
    2-methoxyethanol 455.83
    isobutyl acetate 24.75
    tetrachloromethane 8.64
    n-pentyl acetate 32.63
    transcutol 207.99
    n-heptanol 46.36
    ethylbenzene 8.92
    MIBK 47.98
    2-propoxyethanol 185.93
    tert-butanol 198.67
    MTBE 55.69
    2-butoxyethanol 120.66
    propionic acid 120.23
    o-xylene 15.01
    formic acid 369.65
    diethyl ether 76.48
    m-xylene 13.71
    p-xylene 10.84
    chlorobenzene 9.77
    dimethyl carbonate 87.2
    n-octane 5.97
    formamide 476.06
    cyclopentanone 156.4
    2-pentanone 77.67
    anisole 33.07
    cyclopentyl methyl ether 86.67
    gamma-butyrolactone 148.29
    1-methoxy-2-propanol 314.18
    pyridine 76.11
    3-pentanone 57.6
    furfural 147.13
    n-dodecane 4.42
    diethylene glycol 275.13
    diisopropyl ether 21.83
    tert-amyl alcohol 94.38
    acetylacetone 88.28
    n-hexadecane 4.61
    acetophenone 40.24
    methyl propionate 72.86
    isopentyl acetate 25.94
    trichloroethylene 33.68
    n-nonanol 38.32
    cyclohexanol 70.86
    benzyl alcohol 51.55
    2-ethylhexanol 27.7
    isooctanol 30.47
    dipropyl ether 50.32
    1,2-dichlorobenzene 9.67
    ethyl lactate 63.39
    propylene carbonate 61.6
    n-methylformamide 424.04
    2-pentanol 75.98
    n-pentane 18.92
    1-propoxy-2-propanol 128.26
    1-methoxy-2-propyl acetate 54.51
    2-(2-methoxypropoxy) propanol 89.43
    mesitylene 11.5
    ε-caprolactone 67.6
    p-cymene 10.42
    epichlorohydrin 119.91
    1,1,1-trichloroethane 16.98
    2-aminoethanol 374.87
    morpholine-4-carbaldehyde 349.46
    sulfolane 231.97
    2,2,4-trimethylpentane 4.92
    2-methyltetrahydrofuran 105.89
    n-hexyl acetate 35.46
    isooctane 4.76
    2-(2-butoxyethoxy)ethanol 123.44
    sec-butyl acetate 21.93
    tert-butyl acetate 36.52
    decalin 4.54
    glycerin 390.85
    diglyme 213.16
    acrylic acid 140.64
    isopropyl myristate 19.18
    n-butyric acid 82.7
    acetyl acetate 29.52
    di(2-ethylhexyl) phthalate 26.99
    ethyl propionate 39.33
    nitromethane 300.04
    1,2-diethoxyethane 59.81
    benzonitrile 30.08
    trioctyl phosphate 25.74
    1-bromopropane 23.69
    gamma-valerolactone 185.83
    n-decanol 31.03
    triethyl phosphate 26.59
    4-methyl-2-pentanol 39.7
    propionitrile 72.1
    vinylene carbonate 55.34
    1,1,2-trichlorotrifluoroethane 137.07
    DMS 35.32
    cumene 8.83
    2-octanol 29.64
    2-hexanone 50.35
    octyl acetate 28.28
    limonene 14.98
    1,2-dimethoxyethane 280.7
    ethyl orthosilicate 24.97
    tributyl phosphate 24.55
    diacetone alcohol 90.78
    N,N-dimethylaniline 46.48
    acrylonitrile 104.49
    aniline 44.58
    1,3-propanediol 260.62
    bromobenzene 6.34
    dibromomethane 23.43
    1,1,2,2-tetrachloroethane 37.11
    2-methyl-cyclohexyl acetate 26.6
    tetrabutyl urea 50.75
    diisobutyl methanol 21.27
    2-phenylethanol 42.06
    styrene 10.56
    dioctyl adipate 32.91
    dimethyl sulfate 151.8
    ethyl butyrate 34.23
    methyl lactate 121.36
    butyl lactate 51.0
    diethyl carbonate 26.39
    propanediol butyl ether 111.15
    triethyl orthoformate 33.54
    p-tert-butyltoluene 11.81
    methyl 4-tert-butylbenzoate 54.0
    morpholine 234.68
    tert-butylamine 106.84
    n-dodecanol 25.73
    dimethoxymethane 394.12
    ethylene carbonate 52.79
    cyrene 105.43
    2-ethoxyethyl acetate 43.25
    2-ethylhexyl acetate 19.91
    1,2,4-trichlorobenzene 12.21
    4-methylpyridine 56.67
    dibutyl ether 26.05
    2,6-dimethyl-4-heptanol 21.27
    DEF 138.91
    dimethyl isosorbide 117.26
    tetrachloroethylene 28.68
    eugenol 76.39
    triacetin 45.4
    span 80 81.34
    1,4-butanediol 155.95
    1,1-dichloroethane 26.66
    2-methyl-1-pentanol 46.32
    methyl formate 290.2
    2-methyl-1-butanol 72.51
    n-decane 6.05
    butyronitrile 60.58
    3,7-dimethyl-1-octanol 27.11
    1-chlorooctane 12.36
    1-chlorotetradecane 7.39
    n-nonane 6.12
    undecane 4.98
    tert-butylcyclohexane 4.14
    cyclooctane 7.65
    cyclopentanol 127.19
    tetrahydropyran 92.45
    tert-amyl methyl ether 44.3
    2,5,8-trioxanonane 175.51
    1-hexene 20.14
    2-isopropoxyethanol 133.24
    2,2,2-trifluoroethanol 150.51
    methyl butyrate 54.85

    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