Selenium

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  • Identifiers

    CAS number
    7782-49-2

    Molecular formula
    Se

    SMILES
    [Se]

    Safety labels

    Acute Toxic
    Acute Toxic

    Health Hazard
    Health

  • Odor profile

  • Properties

    pKa est.
    -66.35 (strong acid)

    Molecular weight
    78.97 g/mol

    Melting point expt.

    • 392 °F (NIOSH, 2024)
    • 217
    • 392 °F
    • 220.8 °C (gray selenium); vitreous selenium is transformed to gray selenium at 180 °C; alpha-form transforms to gray at temperatures above 120 °C
    • 217 °C

    Boiling point

    • 1265 °F at 760 mmHg (NIOSH, 2024)
    • 684.9
    • 1265 °F
    • 685 °C

    Flash point

    • -19.86 ˚C est.

    Solubility expt.

    • Insoluble (NIOSH, 2024)
    • Insoluble
    • Soluble in aq potassium cyanide soln, potassium sulfite soln, dilute aqueous caustic alkali soln
    • Insoluble in water and alcohol
    • Soluble in concentrated nitric acid.
    • Soluble in carbon disulfide, 2 mg/100 mL at room temperature; soluble in ether
    • Solubility in water: none
    • Insoluble

  • Synonyms

    • SELENIUM
    • 7782-49-2
    • Elemental selenium
    • Selenium elemental
    • Selenium, elemental
    • Vandex
    • Selen
    • Gray selenium
    • Selenium base
    • Selenium dust
    • Colloidal selenium
    • Selenium metallicum
    • Caswell No. 732
    • SE
    • CI 77805
    • C.I. 77805
    • EPA Pesticide Chemical Code 072001
    • DTXSID9021261
    • B-TRAXIM SE
    • H6241UJ22B
    • SELSAF 2000
    • CHEBI:27568
    • Selenium 80
    • selandiylium
    • Hoarse Cough
    • Dietary Selenium
    • RefChem:182285
    • DTXCID701261
    • CHEBI:36904
    • Bestmade Natural Products Selenium
    • 231-957-4
    • Selanediide
    • Selenide(2-)
    • Selenium-80
    • SELENIUM ATOM
    • SELENIUM POWDER
    • SELENIUM78
    • MFCD00134090
    • Selen [Polish]
    • elenium, elemental; Vandex;
    • Selenium, metallic
    • Selenium, colloidal
    • selenio
    • CCRIS 4250
    • HSDB 4493
    • Selenium Standard: Se @ 10 microg/mL in 2% HNO3
    • EINECS 231-957-4
    • UN2658
    • Selenium Standard: Se @ 1000 microg/mL in 5% HNO3
    • Selenium Standard: Se @ 10000 microg/mL in 5% HNO3
    • Selenium AA Standard: Se @ 1000 microg/mL in 5% HNO3
    • Selenium Standard: Se @ 1000 microg/g in Hydrocarbon Oil
    • Selenium flake
    • Selenium metal
    • UNII-H6241UJ22B
    • Atomic Selenium
    • HSDB 548
    • Selenium element
    • Element Selenium
    • Element-Se
    • Element:Se
    • Element:Selenium
    • SELENIUM STANDARD SOLUTION
    • Se (element)
    • Selenium (atomic)
    • Selenium (Powder)
    • Selenium (element)
    • EINECS 231-978-9
    • Selenium shot, 4N
    • selenium (hexagonal)
    • UN2202
    • Se Standard Solution
    • selenium (iv) hydride
    • HYDROGEN SELENID
    • SELENIUM [MI]
    • SELENIUM [VANDF]
    • Selenium hydride (SeH2)
    • SELENIUM [MART.]
    • 34Se
    • SELENIUM [WHO-DD]
    • UNII-V91P54KPAM
    • EC 231-957-4
    • Selenium, powder, 99+%
    • Selenium compound, n.o.s.
    • SCHEMBL14987
    • Selenium powder, -200 mesh
    • Selenium powder, -325 mesh
    • HYDROGEN SELENIDE [MI]
    • Selenium, p.a., 99.5%
    • CHEMBL1235891
    • CHEMBL6068503
    • HSDB 6909
    • Selenium Nanopowder in aq. media
    • SELENIUM METALLICUM [HPUS]
    • SELENIUM, ELEMENTAL [HSDB]
    • MFCD00011224
    • Se Solution in 1% Nitric Acid*H2O
    • DB11135
    • Selenium 1000 ppm in solution 10%HCl
    • N725
    • Q876
    • Selenium standard solution (100 ppm Se)
    • Selenium, pellets, < 5mm, >=99.999%
    • 7782-49-2(HNO3)
    • AA standard SELENIUM 1M HNO3 1000 ppm
    • E1457
    • NS00099723
    • Selenium ingot/button, ~38mm (1.5in) dia
    • AA standard SELENIUM 1M HNO3 10000 ppm
    • C01529
    • Selenium - Se @ 1000 microg/mL in 5% HNO3
    • ICP standard Selenium 2-5% HNO3 1000 microg/mL
    • Selenium - Se @ 1000 microg/g in Hydrocarbon Oil
    • Selenium powder [UN2658] [Keep away from food]
    • Selenium shot, amorphous, 1-5mm (0.04-0.20in)
    • Selenium, foil, 25x25mm, thickness 3mm, 99.95%
    • Hydrogen selenide, anhydrous [UN2202] [Poison gas]
    • S008000000
    • Selenium, shots, 99.99999% (7N), diameter 2-4 mm
    • Selenium powder, -100 mesh, >= 99.9% (Metals basis)
    • Selenium powder, -200 mesh, >= 99.9% (Metals basis)
    • Selenium powder, -325 mesh, >= 99.99% (Metals basis)
    • Selenium, pellets, <5 mm, >=99.99% trace metals basis
    • Selenium, powder, -100 mesh, >=99.5% trace metals basis
    • Selenium, powder, -100 mesh, 99.99% trace metals basis
    • Selenium Hollow Cathode Lamp: 2.0" Diameter, 4-pin, Cableless
    • Selenium Hollow Cathode Lamp: 1.5" Diameter, 2-pin, Non-Coded
    • 7782-49-2

  • Applications

    Applications of selenium (CAS 7782-49-2) span electronics as a photoconductive material and historical rectifiers; glass and ceramics where selenium compounds act as colorants and decolorizers to achieve red/pink hues or adjust coloration; pigments and inks using selenium sulfide and related compounds; cosmetics and personal care where selenium compounds are used in hair-care formulations such as anti-dandruff products; and agriculture and animal nutrition where selenium is supplied as a trace essential micronutrient in feeds and supplements; it also serves as an intermediate or reagent in chemical synthesis.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 122.07
    methanol 134.0
    isopropanol 87.24
    water 1.78
    ethyl acetate 132.61
    n-propanol 92.54
    acetone 256.68
    n-butanol 90.76
    acetonitrile 147.84
    DMF 397.26
    toluene 92.1
    isobutanol 70.3
    1,4-dioxane 280.32
    methyl acetate 138.57
    THF 347.33
    2-butanone 170.62
    n-pentanol 73.79
    sec-butanol 81.24
    n-hexane 26.75
    ethylene glycol 50.54
    NMP 424.82
    cyclohexane 45.42
    DMSO 374.21
    n-butyl acetate 126.86
    n-octanol 74.95
    chloroform 205.53
    n-propyl acetate 94.86
    acetic acid 158.36
    dichloromethane 174.61
    cyclohexanone 251.56
    propylene glycol 46.12
    isopropyl acetate 86.06
    DMAc 286.06
    2-ethoxyethanol 114.26
    isopentanol 77.23
    n-heptane 32.07
    ethyl formate 90.6
    1,2-dichloroethane 133.78
    n-hexanol 97.69
    2-methoxyethanol 181.09
    isobutyl acetate 67.89
    tetrachloromethane 60.93
    n-pentyl acetate 92.74
    transcutol 397.41
    n-heptanol 65.0
    ethylbenzene 48.39
    MIBK 96.1
    2-propoxyethanol 155.32
    tert-butanol 114.38
    MTBE 113.72
    2-butoxyethanol 107.84
    propionic acid 110.14
    o-xylene 67.89
    formic acid 52.0
    diethyl ether 133.62
    m-xylene 66.79
    p-xylene 68.12
    chlorobenzene 121.56
    dimethyl carbonate 80.56
    n-octane 16.18
    formamide 77.72
    cyclopentanone 338.8
    2-pentanone 154.92
    anisole 116.05
    cyclopentyl methyl ether 171.91
    gamma-butyrolactone 317.16
    1-methoxy-2-propanol 145.22
    pyridine 203.76
    3-pentanone 124.12
    furfural 268.48
    n-dodecane 14.92
    diethylene glycol 137.83
    diisopropyl ether 56.08
    tert-amyl alcohol 95.52
    acetylacetone 190.37
    n-hexadecane 16.65
    acetophenone 115.95
    methyl propionate 116.9
    isopentyl acetate 108.76
    trichloroethylene 235.3
    n-nonanol 66.05
    cyclohexanol 104.9
    benzyl alcohol 82.61
    2-ethylhexanol 72.06
    isooctanol 54.2
    dipropyl ether 91.53
    1,2-dichlorobenzene 113.49
    ethyl lactate 55.63
    propylene carbonate 167.02
    n-methylformamide 128.5
    2-pentanol 70.36
    n-pentane 28.43
    1-propoxy-2-propanol 123.93
    1-methoxy-2-propyl acetate 124.21
    2-(2-methoxypropoxy) propanol 119.9
    mesitylene 51.95
    ε-caprolactone 193.72
    p-cymene 47.1
    epichlorohydrin 222.16
    1,1,1-trichloroethane 154.51
    2-aminoethanol 66.08
    morpholine-4-carbaldehyde 328.82
    sulfolane 371.39
    2,2,4-trimethylpentane 18.31
    2-methyltetrahydrofuran 247.54
    n-hexyl acetate 119.95
    isooctane 15.86
    2-(2-butoxyethoxy)ethanol 158.19
    sec-butyl acetate 69.46
    tert-butyl acetate 108.08
    decalin 25.12
    glycerin 79.54
    diglyme 272.21
    acrylic acid 116.04
    isopropyl myristate 60.81
    n-butyric acid 125.12
    acetyl acetate 111.26
    di(2-ethylhexyl) phthalate 59.51
    ethyl propionate 83.12
    nitromethane 251.41
    1,2-diethoxyethane 151.97
    benzonitrile 120.76
    trioctyl phosphate 45.94
    1-bromopropane 90.91
    gamma-valerolactone 309.02
    n-decanol 53.06
    triethyl phosphate 55.12
    4-methyl-2-pentanol 49.82
    propionitrile 100.8
    vinylene carbonate 147.53
    1,1,2-trichlorotrifluoroethane 170.72
    DMS 108.61
    cumene 39.21
    2-octanol 53.48
    2-hexanone 111.06
    octyl acetate 74.75
    limonene 72.68
    1,2-dimethoxyethane 204.01
    ethyl orthosilicate 54.02
    tributyl phosphate 54.02
    diacetone alcohol 127.04
    N,N-dimethylaniline 89.33
    acrylonitrile 128.8
    aniline 99.42
    1,3-propanediol 90.52
    bromobenzene 121.0
    dibromomethane 135.86
    1,1,2,2-tetrachloroethane 184.76
    2-methyl-cyclohexyl acetate 78.62
    tetrabutyl urea 78.68
    diisobutyl methanol 53.51
    2-phenylethanol 94.12
    styrene 65.66
    dioctyl adipate 79.12
    dimethyl sulfate 144.25
    ethyl butyrate 88.9
    methyl lactate 78.44
    butyl lactate 73.84
    diethyl carbonate 64.7
    propanediol butyl ether 109.19
    triethyl orthoformate 69.69
    p-tert-butyltoluene 48.99
    methyl 4-tert-butylbenzoate 110.21
    morpholine 253.8
    tert-butylamine 79.15
    n-dodecanol 45.23
    dimethoxymethane 194.33
    ethylene carbonate 118.34
    cyrene 124.22
    2-ethoxyethyl acetate 124.52
    2-ethylhexyl acetate 94.67
    1,2,4-trichlorobenzene 133.66
    4-methylpyridine 181.76
    dibutyl ether 89.96
    2,6-dimethyl-4-heptanol 53.51
    DEF 177.27
    dimethyl isosorbide 197.91
    tetrachloroethylene 138.03
    eugenol 111.74
    triacetin 124.38
    span 80 116.38
    1,4-butanediol 47.66
    1,1-dichloroethane 133.2
    2-methyl-1-pentanol 67.37
    methyl formate 111.6
    2-methyl-1-butanol 73.64
    n-decane 21.02
    butyronitrile 103.49
    3,7-dimethyl-1-octanol 68.26
    1-chlorooctane 57.86
    1-chlorotetradecane 31.08
    n-nonane 21.29
    undecane 17.11
    tert-butylcyclohexane 24.45
    cyclooctane 18.7
    cyclopentanol 129.19
    tetrahydropyran 219.61
    tert-amyl methyl ether 96.48
    2,5,8-trioxanonane 213.78
    1-hexene 61.05
    2-isopropoxyethanol 90.13
    2,2,2-trifluoroethanol 66.59
    methyl butyrate 110.4

    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