Selenium Dioxide, Selenium Oxide, Selenious Acid Anhydride, 7446-08-4

Selenium Dioxide, Selenium Oxide, Selenious Acid Anhydride, 7446-08-4

SELENIUM DIOXIDE (SELENIUM OXIDE)

PRODUCT IDENTIFIER INFORMATION

CHEMICAL STRUCTURE

        O
        ||
    Se ← O
    (Oxidation state: +4)
    
    Selenium Dioxide (SeO₂)
    Molecular Structure

Selenium Dioxide Molecular Structure

Molecular Formula: SeO₂
SMILES: O=[Se]=O
InChI: 1S/O2Se/c1-3-2
Molecular Geometry: Trigonal planar (approx.)

SECTION 1: CHEMICAL IDENTITY AND DESCRIPTION

SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES

SECTION 3: CHEMICAL PROPERTIES AND REACTIVITY

SECTION 4: PRODUCTION METHODS

4.1 Direct Oxidation

Reaction:

Se + O₂ → SeO₂

Description:

• Selenium metal is heated in the presence of excess oxygen

• Temperature controlled to prevent formation of unstable Selenium Trioxide (SeO₃)

• Selenium trioxide (SeO₃) may also form under excessive oxygen conditions

4.2 Nitric Acid Oxidation

Reaction:

Se + 2HNO₃ → SeO₂ + H₂O + NO₂ + NO

Byproducts:

• Nitrogen dioxide (NO₂) - toxic brown gas

• Nitrogen monoxide (NO)

• Water (H₂O)

Description:

• Selenium metal is reacted with concentrated nitric acid

• Produces selenium dioxide as the main product

• Byproducts include toxic nitrogen oxides

SECTION 5: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

SECTION 6: MAIN APPLICATION AREAS

SECTION 7: QUALITY SPECIFICATIONS (TECHNICAL GRADE)

SECTION 8: TOXICOLOGICAL PROFILE

SECTION 9: GHS CLASSIFICATION AND LABELING

GHS Classification (according to 1272/2008/EC and UN GHS):

Signal Word: DANGER

Hazard Pictograms: GHS06 (Skull and Crossbones), GHS05 (Corrosion), GHS09 (Environment)

Hazard Statements (H-Codes):

NFPA 704 Hazard Classification:

SECTION 10: PRECAUTIONARY STATEMENTS (P-CODES)

SECTION 11: FIRST AID MEASURES

SECTION 12: FIRE-FIGHTING MEASURES

SECTION 13: STORAGE AND SHELF LIFE

SECTION 14: PACKAGING OPTIONS

SECTION 15: TRANSPORT INFORMATION

SECTION 16: REGULATORY STATUS

SECTION 17: OTHER NAMES AND SYNONYMS

SECTION 18: MARKET AND PRICING FACTORS

Factors Affecting Price:

SECTION 19: SUMMARY TABLE

SECTION 20: CRITICAL WARNINGS AND BEST PRACTICES

CRITICAL WARNINGS:

• Fatal if swallowed, inhaled, or absorbed through skin (H300/H330/H311). Selenium dioxide is highly toxic.

• Causes severe skin burns and eye damage (H314/H318). Use full PPE.

• May cause respiratory irritation (H335). Use adequate ventilation and respiratory protection.

• Causes organ damage through prolonged exposure (H372). Monitor exposure levels.

• Oxidizer: May intensify fire; keep away from combustible materials and reducing agents.

• Very toxic to aquatic life (H410). Prevent environmental release.

• Incompatibilities: Keep away from reducing agents, organic compounds, combustible materials, hydrazine, peroxides, alkali metals, and metal powders.

• Sublimes upon heating: Forms toxic selenium oxide fumes.

• Chronic toxicity: Selenium poisoning (selenosis) may occur with prolonged exposure.

BEST PRACTICE RECOMMENDATIONS:

• Chemical Synthesis: Use as oxidizing agent for selective oxidations; handle in fume hood or closed system; ensure proper waste treatment.

• Glass Industry: Use as colorant; handle with care to avoid inhalation; store in dry conditions.

• Pharmaceutical Industry: Use as synthetic intermediate in cortisone and niacin production; maintain strict quality control.

• Handling: Use in well-ventilated areas or under fume hood; wear chemical-resistant gloves, safety goggles, face shield, and appropriate respiratory protection; avoid creating dust.

• Storage: Store in tightly closed, properly labeled containers in dry conditions; keep away from heat, combustible materials, and reducing agents.

• Spill Response: Avoid creating dust; wear full PPE; scoop into dry, sealable containers; do not use combustible absorbents (sawdust, paper); use vermiculite or other inert absorbents.

• Disposal: Dispose of in accordance with local, regional, and national regulations; do not discharge into drains or water bodies.

LEGAL DISCLAIMER:

The information provided in this document is based on our current knowledge and experience and is presented in good faith. However, as all conditions of use are beyond our control, it does not constitute a binding specification or warranty. This Technical Data Sheet is for informational purposes only. Users are responsible for testing the suitability of the product for their specific applications. For complete safety, storage, use, handling, waste, and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier.