THORIUM OXIDE (ThO2)

Overview IFRA Request a quote

  • Identifiers

    CAS number
    1314-20-1

    Molecular formula
    O2Th

    SMILES
    O=[Th]=O

    Safety labels

    Acute Toxic
    Acute Toxic

    Health Hazard
    Health

  • Odor profile

    Fragrance
    Odorless 92.05%
    Sharp 24.28%
    Sour 22.73%
    Pungent 22.72%
    Burnt 21.38%
    Bitter 14.99%
    Caramellic 13.4%
    Ethereal 11.61%
    Clean 10.83%
    Aromatic 10.15%

     

    Flavor
    Odorless 62.24%
    Bitter 50.51%
    Pungent 28.44%
    Formyl 26.2%
    Vinegar 25.78%
    Rotten 23.2%
    Mustard 23.19%
    Sulfur 19.86%
    Mousy 19.79%
    Nitrile 19.23%

     

  • Properties

    pKa est.
    -256.42 (strong acid)

    Molecular weight
    264.036 g/mol

    Melting point expt.

    • 3390 °C

    Boiling point

    • 4400 °C

    Flash point

    • -241.52 ˚C est.

    Solubility expt.

    • Insoluble in water, alkalies; slightly soluble in acid
    • Soluble in hot sulfuric acid; insoluble in water
    • Partially sol in biological fluids (gastric juice, plasma, etc)

  • Synonyms

    • THORIUM DIOXIDE
    • Thoria
    • 1314-20-1
    • Thorium oxide (ThO2)
    • Umbrathor
    • Thorium anhydride
    • Thortrast
    • Dioxide, Thorium
    • 9XA7X17UQC
    • CHEBI:37339
    • Oxide, Thorium
    • RefChem:189704
    • 215-225-1
    • dioxothorium
    • Thorium(IV) oxide
    • ThO2
    • Thorotrast
    • Thorianite
    • Thorium-232 dioxide
    • HSDB 6364
    • EINECS 215-225-1
    • UNII-9XA7X17UQC
    • SCHEMBL49643
    • Thorium oxide, >=99.0%
    • NS00076164
    • Q420634
    • 1314-20-1

  • Applications

    THORIUM OXIDE (ThO2), CAS 1314-20-1, is used primarily as a high-temperature ceramic material for components such as crucibles and linings, leveraging its very high melting point and chemical stability; it also serves as a stabilizer or dopant in advanced ceramic systems (for example, thoria-stabilized zirconia) to improve high-temperature stability and fracture resistance; in the nuclear materials field it is studied and used as a fertile ceramic fuel material for thorium-based fuel cycles; historically, thorium oxide was a key component of gas mantles for bright white illumination when heated; and in specialty glass and ceramic formulations it can influence refractive index and opacity, supporting coatings and optical materials for high-temperature applications.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 213.72
    methanol 211.73
    isopropanol 197.06
    water 20.8
    ethyl acetate 283.75
    n-propanol 176.39
    acetone 480.32
    n-butanol 176.81
    acetonitrile 312.28
    DMF 917.06
    toluene 209.78
    isobutanol 140.45
    1,4-dioxane 519.0
    methyl acetate 303.49
    THF 727.91
    2-butanone 314.75
    n-pentanol 151.81
    sec-butanol 186.75
    n-hexane 92.58
    ethylene glycol 135.05
    NMP 949.09
    cyclohexane 128.08
    DMSO 877.83
    n-butyl acetate 210.84
    n-octanol 161.66
    chloroform 654.64
    n-propyl acetate 211.12
    acetic acid 311.39
    dichloromethane 598.79
    cyclohexanone 413.44
    propylene glycol 122.36
    isopropyl acetate 211.65
    DMAc 804.06
    2-ethoxyethanol 270.86
    isopentanol 152.72
    n-heptane 87.22
    ethyl formate 222.65
    1,2-dichloroethane 424.33
    n-hexanol 171.51
    2-methoxyethanol 432.56
    isobutyl acetate 151.43
    tetrachloromethane 234.13
    n-pentyl acetate 201.72
    transcutol 474.98
    n-heptanol 146.85
    ethylbenzene 135.97
    MIBK 209.07
    2-propoxyethanol 288.57
    tert-butanol 262.77
    MTBE 270.91
    2-butoxyethanol 233.52
    propionic acid 195.14
    o-xylene 191.1
    formic acid 168.84
    diethyl ether 295.91
    m-xylene 180.09
    p-xylene 174.4
    chlorobenzene 257.08
    dimethyl carbonate 233.02
    n-octane 55.04
    formamide 268.77
    cyclopentanone 574.77
    2-pentanone 294.64
    anisole 272.59
    cyclopentyl methyl ether 375.87
    gamma-butyrolactone 570.6
    1-methoxy-2-propanol 361.21
    pyridine 404.44
    3-pentanone 271.26
    furfural 607.74
    n-dodecane 49.01
    diethylene glycol 282.85
    diisopropyl ether 154.41
    tert-amyl alcohol 237.5
    acetylacetone 413.08
    n-hexadecane 54.03
    acetophenone 268.26
    methyl propionate 278.62
    isopentyl acetate 192.42
    trichloroethylene 637.59
    n-nonanol 149.12
    cyclohexanol 231.96
    benzyl alcohol 197.36
    2-ethylhexanol 140.88
    isooctanol 124.86
    dipropyl ether 203.47
    1,2-dichlorobenzene 283.59
    ethyl lactate 151.09
    propylene carbonate 336.61
    n-methylformamide 337.54
    2-pentanol 164.02
    n-pentane 101.74
    1-propoxy-2-propanol 237.5
    1-methoxy-2-propyl acetate 240.84
    2-(2-methoxypropoxy) propanol 244.04
    mesitylene 149.86
    ε-caprolactone 354.67
    p-cymene 122.26
    epichlorohydrin 563.04
    1,1,1-trichloroethane 466.39
    2-aminoethanol 165.11
    morpholine-4-carbaldehyde 722.93
    sulfolane 837.98
    2,2,4-trimethylpentane 66.94
    2-methyltetrahydrofuran 457.68
    n-hexyl acetate 228.13
    isooctane 53.65
    2-(2-butoxyethoxy)ethanol 280.98
    sec-butyl acetate 161.96
    tert-butyl acetate 262.08
    decalin 76.01
    glycerin 205.82
    diglyme 476.72
    acrylic acid 217.22
    isopropyl myristate 144.99
    n-butyric acid 226.46
    acetyl acetate 260.15
    di(2-ethylhexyl) phthalate 142.0
    ethyl propionate 206.57
    nitromethane 542.43
    1,2-diethoxyethane 248.89
    benzonitrile 237.14
    trioctyl phosphate 118.53
    1-bromopropane 286.44
    gamma-valerolactone 592.01
    n-decanol 125.9
    triethyl phosphate 150.51
    4-methyl-2-pentanol 120.16
    propionitrile 213.11
    vinylene carbonate 317.08
    1,1,2-trichlorotrifluoroethane 479.77
    DMS 222.3
    cumene 113.3
    2-octanol 132.44
    2-hexanone 225.34
    octyl acetate 170.41
    limonene 173.09
    1,2-dimethoxyethane 468.45
    ethyl orthosilicate 150.23
    tributyl phosphate 123.25
    diacetone alcohol 289.26
    N,N-dimethylaniline 252.43
    acrylonitrile 276.44
    aniline 238.67
    1,3-propanediol 209.79
    bromobenzene 279.3
    dibromomethane 468.35
    1,1,2,2-tetrachloroethane 586.03
    2-methyl-cyclohexyl acetate 183.49
    tetrabutyl urea 183.64
    diisobutyl methanol 118.14
    2-phenylethanol 195.32
    styrene 168.75
    dioctyl adipate 190.04
    dimethyl sulfate 429.61
    ethyl butyrate 195.89
    methyl lactate 213.71
    butyl lactate 169.97
    diethyl carbonate 154.98
    propanediol butyl ether 218.46
    triethyl orthoformate 172.24
    p-tert-butyltoluene 131.01
    methyl 4-tert-butylbenzoate 273.87
    morpholine 501.81
    tert-butylamine 207.64
    n-dodecanol 112.12
    dimethoxymethane 533.17
    ethylene carbonate 255.1
    cyrene 288.39
    2-ethoxyethyl acetate 244.46
    2-ethylhexyl acetate 175.22
    1,2,4-trichlorobenzene 341.89
    4-methylpyridine 394.17
    dibutyl ether 168.45
    2,6-dimethyl-4-heptanol 118.14
    DEF 415.92
    dimethyl isosorbide 396.31
    tetrachloroethylene 417.9
    eugenol 262.82
    triacetin 264.96
    span 80 239.96
    1,4-butanediol 117.61
    1,1-dichloroethane 407.27
    2-methyl-1-pentanol 142.74
    methyl formate 303.09
    2-methyl-1-butanol 148.35
    n-decane 65.3
    butyronitrile 215.35
    3,7-dimethyl-1-octanol 143.34
    1-chlorooctane 145.43
    1-chlorotetradecane 87.25
    n-nonane 65.54
    undecane 55.17
    tert-butylcyclohexane 71.7
    cyclooctane 71.24
    cyclopentanol 277.69
    tetrahydropyran 388.7
    tert-amyl methyl ether 260.4
    2,5,8-trioxanonane 380.46
    1-hexene 150.97
    2-isopropoxyethanol 215.69
    2,2,2-trifluoroethanol 223.57
    methyl butyrate 240.47

    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