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Selenium dioxide

CAS Number
7446-08-4
EC Number
231-194-7
Chemical Formula
O2Se
Molecular Weight
110.97 g/mol
Industries:Mining & Metals

Description

Selenium dioxide (CAS 7446-08-4 ), also known as selenious anhydride, is an inorganic oxidizing agent used primarily as a catalyst and reagent in chemical synthesis and industrial refining. SeO2 enables selective oxidation reactions that are difficult to achieve with conventional oxidants, making it a targeted choice for specialty chemical production and advanced manufacturing. In organic synthesis, it is the reagent of choice for allylic and benzylic oxidations, converting methylene groups to carbonyl compounds in pharmaceutical and fine chemical intermediates. The electronics industry relies on it as a component in glass and ceramic formulations where controlled selenium incorporation modifies optical and electrical properties for high-tech use. In metallurgy and mining, it functions as a refining agent for copper and other non-ferrous metals, removing impurities during electrorefining processes to ensure high metal purity. It also serves as a precursor in the production of other selenium compounds used across pigment and catalyst manufacturing, supporting a wide range of industrial chemical applications. The product is supplied as a white crystalline powder. Technical and reagent grades are the standard market offerings, with purity levels typically ranging from 99% upward for use. Packaging is available in small quantities for research use through to bulk quantities for industrial procurement, with handling requirements reflecting its oxidizing classification. Contact us for supply of Selenium dioxide Request Quote

Other Names (Synonyms)

Selenous anhydride | Selenium(IV) oxide | Selenious anhydride | Selenium oxide (SeO2) | Selenium dioxide dimer | Selenous acid anhydride | Selenium(IV) dioxide (1:2) | Selenium oxide (Se2O4) | SeO2

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point340 °C
Boiling Point684.9 °C(lit.)
Density3.954 g/cm³ @ Temp: 15 °C
Flash Point315°C
AppearanceSelenium dioxide is white to slightly reddish crystalline solid or yellow liquid which forms a yellowgreen vapor. It has a sour and pungent odor. Odor threshold in air50.0002 milligram per cubic meter.
Colorwhite
Formpowder
Water Solubility38.4 g/100 mL (14 ºC)
Vapor Pressure1 mm Hg ( 157 °C)
Refractive IndexnD20 <1.76
pH2 (10g/l, H2O, 20℃)

Safety & Handling

Danger
GHS05· CorrosiveGHS06· ToxicGHS08· Health HazardGHS09· EnvironmentGHS07· Irritant

Hazard Statements

H300Fatal if swallowed
H301Toxic if swallowed
H314Causes severe skin burns and eye damage
H318Causes serious eye damage
H319Causes serious eye irritation
H331Toxic if inhaled
H370Causes damage to organs
H371May cause damage to organs
H372Causes damage to organs through prolonged or repeated exposure
H373May causes damage to organs through prolonged or repeated exposure
H400Very toxic to aquatic life
H410Very toxic to aquatic life with long lasting effects

Precautionary Statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.
P261Avoid breathing dust/fume/gas/mist/vapours/spray.
P264Wash … thoroughly after handling.
P270Do not eat, drink or smoke when using this product.
P271Use only outdoors or in a well-ventilated area.
P273Avoid release to the environment.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P319Get medical advice/attention if you feel unwell.
P321Specific treatment (see … on this label).
P330Rinse mouth.
P363Wash contaminated clothing before reuse.
P391Collect spillage.
P405Store locked up.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P316Get emergency medical help immediately.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P316Get emergency medical help immediately.
P317If eye irritation persists: Get medical advice/attention. Get emergency medical help.
P233Store in a well-ventilated place. Keep container tightly closed.
P331Rinse mouth. Do NOT induce vomiting.
P354IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code28112900
UN Number3440
ADR Class6.1
Packing GroupIII
Storage Class6.1C - Combustible acute toxic Cat.3 toxic compounds or compounds which causing chronic effects
WGK (Germany)2