Antimony Trioxide

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  • Identifiers

    CAS number
    1309-64-4

    Molecular formula
    O3Sb2

    SMILES
    [O-2].[O-2].[O-2].[Sb+3].[Sb+3]

    Safety labels

    Health Hazard
    Health

  • Odor profile

    Odor impact est.
    High

  • Properties

    pKa est.
    -5.32 (strong acid)

    Molecular weight
    291.52 g/mol

    Melting point expt.

    • 1211 °F (NTP, 1992)
    • 655 °C
    • 656 °C

    Boiling point

    • 2822 °F at 760 mmHg (sublimes); 1598 °F at 210 mmHg (NTP, 1992)
    • 1425 °C
    • 1550 °C (partially sublimes)

    Flash point

    • -62.09 ˚C est.
    • Not Applicable. Not flammable. (USCG, 1999)

    Solubility expt.

    • less than 1 mg/mL at 68 °F (NTP, 1992)
    • Slightly soluble in water
    • Very slightly soluble in water
    • Soluble in KOH
    • Soluble in concentrated hydrochloric and sulfuric acids, strong alkalies
    • Slightly soluble in dilute sulfuric acid, or dilute nitric acid; solubility in dilute hydrochloric acid (0.1 moles HCl/kg water: approximately 1X10-4 g-atoms Sb/kg water) ... solubility increases with increasing concentration of hydrochloric acid.. Soluble in solutions of alkali hydroxides or sulfides, in warm solution of tartaric acid or of bitartrates.
    • Solubility in water, g/l at 22.2 °C: 0.0033 (none)

  • Synonyms

    • Diantimony trioxide
    • Antimonious oxide
    • Exitelite
    • Timonox
    • Twinkling star
    • Antimony White
    • Thermoguard B
    • Thermoguard L
    • Thermoguard S
    • White star
    • Fireshield H
    • Dechlorane A-O
    • Stibiox MS
    • Amspec-KR
    • Patox C
    • Patox H
    • Patox L
    • Patox M
    • Patox S
    • Atox B
    • Atox F
    • Atox R
    • Atox S
    • Antimony oxide (Sb2O3)
    • Antimony sesquioxide
    • Timonox White Star
    • Microfine A 05
    • Octoguard FR 10
    • Flameguard VF 59
    • Chemetron fire shield
    • Antimony(3+) oxide
    • Flame Cut 610
    • Flame Cut 610R
    • Antimony Bloom 100A
    • Antimony Bloom 500A
    • Weisspiessglanz
    • Nyacol A 1510LP
    • Fireshield FSPO 405
    • Nyacol A 1530
    • AP 50 (metal oxide)
    • NCI-C55152
    • AT 3B
    • LSB 80
    • AP 50
    • A 1588LP
    • ANTIMONIUM OXYDATUM
    • Antimony oxide (SB203)
    • P217481X5E
    • CI 77052
    • C.I. 77052
    • A 1582
    • oxostibanyl stibinate
    • RefChem:113184
    • DTXCID303880
    • 1309-64-4
    • 215-175-0
    • Antimony Trioxide
    • Antox
    • DTXSID4023880
    • Senarmontite
    • antimony(3+);oxygen(2-)
    • oxygen(-2) anion
    • 12412-52-1
    • Valentinite
    • FireShield LS-FR
    • LS-FR
    • Weisspiessglanz [German]
    • AT 3 (fireproofing agent)
    • MIC 3
    • CCRIS 4495
    • HSDB 436
    • HM 203P
    • EINECS 215-175-0
    • EINECS 215-474-6
    • AN 800
    • Nyacol A-1530
    • O3Sb2
    • Sb2O3,
    • SCHEMBL302281
    • ANTIMONY TRIOXIDE [MI]
    • ANTIMONY TRIOXIDE [HSDB]
    • ANTIMONY TRIOXIDE [IARC]
    • UNII-P217481X5E
    • ANTIMONIUM OXYDATUM [HPUS]
    • AKOS030228225
    • EC 215-175-0
    • Q409035
    • 1317-98-2
    • 1309-64-4

  • Applications

    Antimony Trioxide (CAS 1309-64-4) is widely used as a flame-retardant synergist in polymers and coatings, boosting the performance of halogenated flame retardants in plastics such as PVC, polyurethane foams, and textiles. It also serves as a catalyst in polyester (PET) production, supporting polycondensation processes. In PVC formulations, Sb2O3 acts as a heat stabilizer to prevent degradation during processing and use. Additionally, it is added to coatings, inks, and papers to improve flame retardancy. It is used in flame-retardant-treated textiles and in electronic applications as a flame-retardant additive in epoxy/resin systems for PCB laminates and cable insulation. Use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 118.16
    methanol 198.71
    isopropanol 83.91
    water 17.02
    ethyl acetate 38.37
    n-propanol 70.23
    acetone 104.14
    n-butanol 54.72
    acetonitrile 95.16
    DMF 309.03
    toluene 10.79
    isobutanol 48.03
    1,4-dioxane 88.33
    methyl acetate 60.53
    THF 86.2
    2-butanone 57.28
    n-pentanol 36.4
    sec-butanol 57.06
    n-hexane 4.65
    ethylene glycol 81.26
    NMP 165.23
    cyclohexane 5.12
    DMSO 222.27
    n-butyl acetate 19.92
    n-octanol 23.69
    chloroform 33.26
    n-propyl acetate 22.47
    acetic acid 126.93
    dichloromethane 42.46
    cyclohexanone 45.28
    propylene glycol 55.44
    isopropyl acetate 20.96
    DMAc 185.24
    2-ethoxyethanol 75.22
    isopentanol 44.3
    n-heptane 3.92
    ethyl formate 35.18
    1,2-dichloroethane 33.54
    n-hexanol 28.18
    2-methoxyethanol 142.46
    isobutyl acetate 12.9
    tetrachloromethane 7.77
    n-pentyl acetate 17.3
    transcutol 176.35
    n-heptanol 16.32
    ethylbenzene 8.08
    MIBK 24.93
    2-propoxyethanol 56.69
    tert-butanol 94.14
    MTBE 47.84
    2-butoxyethanol 34.99
    propionic acid 68.95
    o-xylene 12.8
    formic acid 94.17
    diethyl ether 44.35
    m-xylene 10.2
    p-xylene 11.16
    chlorobenzene 16.12
    dimethyl carbonate 29.89
    n-octane 2.22
    formamide 118.96
    cyclopentanone 64.43
    2-pentanone 39.07
    anisole 28.53
    cyclopentyl methyl ether 34.25
    gamma-butyrolactone 81.15
    1-methoxy-2-propanol 88.29
    pyridine 45.89
    3-pentanone 30.97
    furfural 71.88
    n-dodecane 2.65
    diethylene glycol 71.12
    diisopropyl ether 13.16
    tert-amyl alcohol 63.83
    acetylacetone 43.19
    n-hexadecane 2.79
    acetophenone 25.63
    methyl propionate 42.55
    isopentyl acetate 18.69
    trichloroethylene 45.89
    n-nonanol 19.96
    cyclohexanol 34.26
    benzyl alcohol 25.79
    2-ethylhexanol 16.04
    isooctanol 13.16
    dipropyl ether 17.42
    1,2-dichlorobenzene 16.77
    ethyl lactate 18.95
    propylene carbonate 35.3
    n-methylformamide 128.01
    2-pentanol 37.15
    n-pentane 6.15
    1-propoxy-2-propanol 37.28
    1-methoxy-2-propyl acetate 26.24
    2-(2-methoxypropoxy) propanol 43.36
    mesitylene 8.35
    ε-caprolactone 40.67
    p-cymene 7.59
    epichlorohydrin 59.47
    1,1,1-trichloroethane 22.59
    2-aminoethanol 84.1
    morpholine-4-carbaldehyde 141.67
    sulfolane 94.12
    2,2,4-trimethylpentane 4.25
    2-methyltetrahydrofuran 52.76
    n-hexyl acetate 29.43
    isooctane 3.32
    2-(2-butoxyethoxy)ethanol 57.56
    sec-butyl acetate 14.42
    tert-butyl acetate 25.94
    decalin 3.54
    glycerin 78.37
    diglyme 97.08
    acrylic acid 74.3
    isopropyl myristate 13.15
    n-butyric acid 48.69
    acetyl acetate 25.98
    di(2-ethylhexyl) phthalate 13.37
    ethyl propionate 22.18
    nitromethane 163.38
    1,2-diethoxyethane 37.27
    benzonitrile 27.28
    trioctyl phosphate 10.83
    1-bromopropane 19.63
    gamma-valerolactone 84.07
    n-decanol 15.81
    triethyl phosphate 11.96
    4-methyl-2-pentanol 20.47
    propionitrile 47.18
    vinylene carbonate 32.62
    1,1,2-trichlorotrifluoroethane 59.75
    DMS 28.45
    cumene 7.3
    2-octanol 13.12
    2-hexanone 25.82
    octyl acetate 17.72
    limonene 11.1
    1,2-dimethoxyethane 103.24
    ethyl orthosilicate 11.54
    tributyl phosphate 12.86
    diacetone alcohol 43.14
    N,N-dimethylaniline 25.01
    acrylonitrile 67.51
    aniline 23.83
    1,3-propanediol 87.33
    bromobenzene 13.42
    dibromomethane 25.7
    1,1,2,2-tetrachloroethane 35.88
    2-methyl-cyclohexyl acetate 14.79
    tetrabutyl urea 19.6
    diisobutyl methanol 11.97
    2-phenylethanol 20.91
    styrene 11.27
    dioctyl adipate 18.55
    dimethyl sulfate 51.39
    ethyl butyrate 16.58
    methyl lactate 37.15
    butyl lactate 18.14
    diethyl carbonate 13.68
    propanediol butyl ether 45.29
    triethyl orthoformate 13.95
    p-tert-butyltoluene 7.68
    methyl 4-tert-butylbenzoate 28.05
    morpholine 97.69
    tert-butylamine 52.05
    n-dodecanol 12.64
    dimethoxymethane 95.49
    ethylene carbonate 26.6
    cyrene 33.82
    2-ethoxyethyl acetate 26.75
    2-ethylhexyl acetate 14.35
    1,2,4-trichlorobenzene 21.53
    4-methylpyridine 42.12
    dibutyl ether 20.26
    2,6-dimethyl-4-heptanol 11.97
    DEF 71.99
    dimethyl isosorbide 49.92
    tetrachloroethylene 27.03
    eugenol 32.14
    triacetin 31.46
    span 80 32.6
    1,4-butanediol 39.11
    1,1-dichloroethane 28.98
    2-methyl-1-pentanol 29.2
    methyl formate 83.94
    2-methyl-1-butanol 40.93
    n-decane 3.6
    butyronitrile 36.58
    3,7-dimethyl-1-octanol 20.87
    1-chlorooctane 11.13
    1-chlorotetradecane 5.92
    n-nonane 3.48
    undecane 3.03
    tert-butylcyclohexane 3.74
    cyclooctane 2.15
    cyclopentanol 42.57
    tetrahydropyran 49.7
    tert-amyl methyl ether 35.98
    2,5,8-trioxanonane 74.27
    1-hexene 12.72
    2-isopropoxyethanol 43.75
    2,2,2-trifluoroethanol 44.41
    methyl butyrate 29.42

    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