Silicon Dioxide

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  • Identifiers

    CAS number
    7631-86-9

    Molecular formula
    O2Si

    SMILES
    O=[Si]=O

    Safety labels

    Health Hazard
    Health

  • Odor profile

    Odorless 93.88%
    Sharp 20.67%
    Sour 20.28%
    Pungent 19.92%
    Burnt 19.1%
    Bitter 13.89%
    Caramellic 11.21%
    Clean 10.65%
    Ethereal 9.89%
    Aromatic 9.42%

    Scent© AI

  • Properties

    Molecular weight
    60.084 g/mol

    Melting point expt.

    • 3110 °F (NIOSH, 2024)
    • 3110 °F
    • 1710 °C
    • 1716 - 1736 °C
    • 1713 °C

    Boiling point

    • 4046 °F at 760 mmHg (NIOSH, 2024)
    • 4046 °F
    • 2230 °C

    Flash point est.
    4.84 ˚C

    Solubility expt.

    • Insoluble (NIOSH, 2024)
    • The solubility of the various phases of silicas is very complex and depends upon several factors. Solubility increases with temperature and pH and is affected by the presence of trace metals. Particle size influences the rate of solubility. /Silica/
    • Insoluble
    • Silica is rather poorly soluble in water although solubility is higher for the amorphous than for the crystalline morphologies. ... The external amorphous layer in quartz is more soluble than the crystalline underlying core.
    • AMORPHOUS IS SOL IN ALKALIES, ESP WHEN FINELY DIVIDED
    • Practically insoluble in water or acids. Dissolves readily in HF, forming silicon tetrafluoride.
    • Very slightly sol in alkali.
    • Soluble in hot potassium hydroxide and hot sodium hydroxide solutions. Insoluble in ethanol.
    • Silica is rather poorly soluble in water and solubility is lower for the crystalline than for the amorphous morphologies. ...Solubility increases with temperature and pH and is affected by the presence of trace metals. Particle size influences the rate of solubility.
    • The external amorphous layer in quartz (the Beilby layer) is more soluble than the crystalline underlying core.
    • Solubility in water: none
    • Insoluble
    • Insoluble

  • Synonyms

    • SILICON DIOXIDE
    • Silica
    • Dioxosilane
    • Quartz
    • 7631-86-9
    • Cristobalite
    • Tridymite
    • 112926-00-8
    • 112945-52-5
    • 14808-60-7
    • Silicic anhydride
    • Sand
    • Aerosil
    • Diatomaceous silica
    • 14464-46-1
    • 60676-86-0
    • Wessalon
    • Celite
    • Silicon(IV) oxide
    • Zorbax sil
    • Silica, amorphous
    • QUARTZ (SIO2)
    • Dicalite
    • Ludox
    • Nyacol
    • Amorphous silica
    • Synthetic amorphous silica
    • Cristobalite (SiO2)
    • Cab-O-sil
    • SILICA, VITREOUS
    • Sillikolloid
    • Extrusil
    • Santocel
    • Sipernat
    • Superfloss
    • Acticel
    • Carplex
    • Neosil
    • Neosyl
    • Porasil
    • Silikil
    • Siloxid
    • Zipax
    • Aerosil-degussa
    • Aerosil 380
    • Quartz sand
    • Rose quartz
    • Silica particles
    • Cab-o-sil M-5
    • Snowtex O
    • Silica, colloidal
    • Tokusil TPLM
    • Dri-Die
    • Manosil vn 3
    • Colloidal silicon dioxide
    • Ultrasil VH 3
    • Ultrasil VN 3
    • Aerosil bs-50
    • Carplex 30
    • Carplex 80
    • Snowtex 30
    • Zeofree 80
    • Aerosil K 7
    • Cabosil N 5
    • Syton 2X
    • Amorphous silica gel
    • Positive sol 232
    • Siliziumdioxid
    • Aerogel 200
    • Aerosil 300
    • Chalcedony
    • Diatomite
    • Ludox hs 40
    • Silanox 101
    • Silica (SiO2)
    • Vitasil 220
    • Agate
    • Positive sol 130M
    • Silica vitreous
    • Silicon dioxide (amorphous)
    • Aerosil A 300
    • Aerosil E 300
    • Aerosil M-300
    • colloidal silica
    • Fused silica
    • Quartz glass
    • Silica slurry
    • Silicon dioxide, fumed
    • Silicone dioxide
    • Nalfloc N 1050
    • Quso 51
    • Silica, amorphous fused
    • Nalco 1050
    • Quso G 30
    • 15468-32-3
    • Hydrophobic silica 2482
    • Kieselsaeureanhydrid
    • Min-U-Sil
    • SiO2
    • CCRIS 3699
    • Silica aerogel
    • (SiO2)n
    • UNII-ETJ7Z6XBU4
    • ETJ7Z6XBU4
    • Silicon Dioxide, Amorphous
    • Silica 2482, hydrophobic
    • Silicon dioxide, chemically prepared
    • 15723-40-7
    • 99439-28-8
    • EINECS 231-545-4
    • CAB-O-SIL N-70TS
    • Silica Gel, 40-63 Micron Particles
    • EPA Pesticide Chemical Code 072605
    • CI 7811
    • Aerosil 200
    • 13778-37-5
    • CHEBI:30563
    • AI3-25549
    • Crystalline silica
    • N1030
    • U 333
    • Silica gel 60, 230-400 mesh
    • MFCD00011232
    • MFCD00217788
    • Silicon dioxide, colloidal
    • ENT 25,550
    • [SiO2]
    • Silica, crystalline - fused

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 518.79
    methanol 648.85
    isopropanol 423.89
    water 83.55
    ethyl acetate 144.88
    n-propanol 343.0
    acetone 363.95
    n-butanol 299.18
    acetonitrile 233.87
    DMF 1104.85
    toluene 83.57
    isobutanol 216.19
    1,4-dioxane 315.65
    methyl acetate 168.01
    THF 507.13
    2-butanone 206.94
    n-pentanol 198.75
    sec-butanol 301.59
    n-hexane 67.3
    ethylene glycol 283.82
    NMP 457.73
    cyclohexane 61.51
    DMSO 960.21
    n-butyl acetate 82.92
    n-octanol 130.95
    chloroform 238.6
    n-propyl acetate 92.76
    acetic acid 269.37
    dichloromethane 256.69
    cyclohexanone 168.77
    propylene glycol 233.46
    isopropyl acetate 103.52
    DMAc 534.3
    2-ethoxyethanol 311.03
    isopentanol 203.02
    n-heptane 50.52
    ethyl formate 142.23
    1,2-dichloroethane 206.79
    n-hexanol 166.45
    2-methoxyethanol 610.27
    isobutyl acetate 53.27
    tetrachloromethane 85.54
    n-pentyl acetate 94.14
    transcutol 310.15
    n-heptanol 129.08
    ethylbenzene 51.61
    MIBK 129.66
    2-propoxyethanol 285.26
    tert-butanol 442.6
    MTBE 240.18
    2-butoxyethanol 198.64
    propionic acid 186.08
    o-xylene 72.37
    formic acid 246.05
    diethyl ether 311.13
    m-xylene 73.42
    p-xylene 56.57
    chlorobenzene 75.92
    dimethyl carbonate 138.35
    n-octane 30.75
    formamide 385.65
    cyclopentanone 261.74
    2-pentanone 202.2
    anisole 114.8
    cyclopentyl methyl ether 224.69
    gamma-butyrolactone 250.63
    1-methoxy-2-propanol 469.05
    pyridine 191.28
    3-pentanone 143.56
    furfural 243.02
    n-dodecane 25.33
    diethylene glycol 291.66
    diisopropyl ether 104.23
    tert-amyl alcohol 303.92
    acetylacetone 158.41
    n-hexadecane 26.61
    acetophenone 90.88
    methyl propionate 172.34
    isopentyl acetate 68.46
    trichloroethylene 213.59
    n-nonanol 113.76
    cyclohexanol 190.13
    benzyl alcohol 104.91
    2-ethylhexanol 84.73
    isooctanol 94.09
    dipropyl ether 132.86
    1,2-dichlorobenzene 76.07
    ethyl lactate 81.67
    propylene carbonate 118.02
    n-methylformamide 443.93
    2-pentanol 231.93
    n-pentane 97.53
    1-propoxy-2-propanol 203.8
    1-methoxy-2-propyl acetate 97.83
    2-(2-methoxypropoxy) propanol 129.6
    mesitylene 59.49
    ε-caprolactone 140.18
    p-cymene 40.77
    epichlorohydrin 279.68
    1,1,1-trichloroethane 140.98
    2-aminoethanol 340.39
    morpholine-4-carbaldehyde 375.8
    sulfolane 331.26
    2,2,4-trimethylpentane 34.19
    2-methyltetrahydrofuran 292.64
    n-hexyl acetate 112.49
    isooctane 31.98
    2-(2-butoxyethoxy)ethanol 186.47
    sec-butyl acetate 60.89
    tert-butyl acetate 120.2
    decalin 27.57
    glycerin 310.77
    diglyme 293.95
    acrylic acid 172.53
    isopropyl myristate 57.82
    n-butyric acid 190.06
    acetyl acetate 70.24
    di(2-ethylhexyl) phthalate 50.65
    ethyl propionate 96.23
    nitromethane 348.52
    1,2-diethoxyethane 136.96
    benzonitrile 87.29
    trioctyl phosphate 50.59
    1-bromopropane 160.62
    gamma-valerolactone 269.63
    n-decanol 89.53
    triethyl phosphate 45.35
    4-methyl-2-pentanol 123.15
    propionitrile 171.2
    vinylene carbonate 103.8
    1,1,2-trichlorotrifluoroethane 223.56
    DMS 77.69
    cumene 42.18
    2-octanol 110.62
    2-hexanone 111.6
    octyl acetate 74.84
    limonene 58.36
    1,2-dimethoxyethane 387.52
    ethyl orthosilicate 48.6
    tributyl phosphate 49.15
    diacetone alcohol 194.02
    N,N-dimethylaniline 114.48
    acrylonitrile 206.08
    aniline 129.35
    1,3-propanediol 350.52
    bromobenzene 71.48
    dibromomethane 205.27
    1,1,2,2-tetrachloroethane 213.13
    2-methyl-cyclohexyl acetate 55.75
    tetrabutyl urea 79.25
    diisobutyl methanol 68.79
    2-phenylethanol 93.67
    styrene 63.75
    dioctyl adipate 67.35
    dimethyl sulfate 209.88
    ethyl butyrate 67.97
    methyl lactate 155.87
    butyl lactate 85.57
    diethyl carbonate 47.79
    propanediol butyl ether 183.9
    triethyl orthoformate 58.2
    p-tert-butyltoluene 45.52
    methyl 4-tert-butylbenzoate 112.5
    morpholine 383.5
    tert-butylamine 292.86
    n-dodecanol 72.63
    dimethoxymethane 531.57
    ethylene carbonate 91.2
    cyrene 110.51
    2-ethoxyethyl acetate 104.66
    2-ethylhexyl acetate 56.85
    1,2,4-trichlorobenzene 85.7
    4-methylpyridine 173.1
    dibutyl ether 97.95
    2,6-dimethyl-4-heptanol 68.79
    DEF 275.68
    dimethyl isosorbide 162.31
    tetrachloroethylene 170.19
    eugenol 126.85
    triacetin 84.84
    span 80 128.53
    1,4-butanediol 164.79
    1,1-dichloroethane 180.84
    2-methyl-1-pentanol 134.72
    methyl formate 282.18
    2-methyl-1-butanol 190.17
    n-decane 37.27
    butyronitrile 166.98
    3,7-dimethyl-1-octanol 87.21
    1-chlorooctane 73.43
    1-chlorotetradecane 39.74
    n-nonane 37.84
    undecane 29.8
    tert-butylcyclohexane 29.72
    cyclooctane 30.85
    cyclopentanol 251.81
    tetrahydropyran 256.34
    tert-amyl methyl ether 201.94
    2,5,8-trioxanonane 219.41
    1-hexene 111.75
    2-isopropoxyethanol 206.47
    2,2,2-trifluoroethanol 131.26
    methyl butyrate 116.95

    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