Molekula
Selenium dioxide
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Selenium dioxide is a highly reactive inorganic compound composed of selenium and oxygen, primarily used as an oxidizing agent in organic synthesis, dye manufacturing, and as a reagent in chemical analysis. It is also employed in the production of glass and ceramics for its colorant properties, and as a starting material for the preparation of other selenium compounds. This chemical has a CAS number of 7446-08-4, with the molecular formula SeO2 and a molecular weight of 110.96 g/mol. It should be stored at ambient conditions but handled with caution, as it carries a Danger signal word due to its hazardous nature. Molekula supplies selenium dioxide from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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25 g — £37.30 per pack ex VAT · £44.76 inc. VAT
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100 g — £68.50 per pack ex VAT · £82.20 inc. VAT
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500 g — £218.10 per pack ex VAT · £261.72 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | White to off-white or Pink powder |
| Identification | Conforms to reference |
| Assay | ≥98% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Transport Class | 6.1 |
| Packing Group | II |
| Acidity | Acid |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | Lustrous tetragonal needles; yellowish green vapor |
| Odour | Vapor has a pungent sour smell |
| Melting Point | 340 °C under pressure |
| Boiling Point | 315 °C at 760 mmHg (sublimes) |
| Water Solubility | 400 g/L at 20 °C |
| Solubility (other solvents) | Soluble in concentrated sulfuric acid |
| Vapour Pressure | 1.65 kPa at 70 °C |
Source: PubChem CID 24007 (HSDB, CAMEO Chemicals, ICSC)
Identification
| Property | Value |
|---|---|
| SKU | 30100275 |
| CAS Number | 7446-08-4 |
| IUPAC Name | selenium dioxide |
| EC Number | 231-194-7 |
| Molecular Formula | SeO2 |
| Molecular Weight | 110.96 |
| Exact Mass | 111.9064 |
| SMILES | O=[Se]=O |
| InChIKey | JPJALAQPGMAKDF-UHFFFAOYSA-N |
| InChI | InChI=1S/O2Se/c1-3-2 |
| PubChem CID | 24007 |
| UN Number | UN3283 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2811.29.2000 |
| Tariff Code | 2811299090 |
Safety & GHS
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Corrosive
GHS05
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Toxic
GHS06
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Serious Health Hazard
GHS08
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Hazardous to the Environment
GHS09
Hazard statements
- H300 Fatal if swallowed
- H314 (sub cat. 1B) Causes severe skin burns and eye damage
- H331 Toxic if inhaled
- H372 Causes damage to organs through prolonged or repeated exposure
- H410 Very toxic to aquatic life with long lasting effects
Precautionary statements
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P273 Avoid release to the environment
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+310 IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician
- P302+352 IF ON SKIN: Wash with soap and water
- P304+312 IF INHALED: Call a POISON CENTER or doctor/physician if you feel unwell
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- (oxo-lambda4-selanylidene)oxidane
- Dioxide, Selenium
- Oxide, Selenium
- Selenious anhydride
- Selenium dioxide dimer
- Selenium oxide (1:2)
- Selenium oxide (Se2O4)
- Selenium oxide (SeO2)
- Selenium(IV) dioxide (1:2)
- Selenous acid anhydride
Frequently asked questions
What is selenium dioxide primarily used for?
Selenium dioxide is commonly used as an oxidizing agent in organic synthesis, as a reagent in the production of selenides, and in the manufacturing of glass, ceramics, and pigments.
What is the chemical formula and molecular weight of selenium dioxide?
The chemical formula is SeO₂, and the molecular weight is 110.96 g/mol.
How should selenium dioxide be stored?
Store selenium dioxide in a cool, dry place at ambient temperature, away from incompatible substances like strong oxidizers or reducing agents.
What grades of selenium dioxide does Molekula supply?
Molekula supplies technical and reagent-grade selenium dioxide, depending on your application requirements.
Can Molekula supply selenium dioxide in bulk quantities?
Yes, Molekula can provide selenium dioxide in bulk packaging (e.g., drums or bags) for industrial or large-scale applications—please contact us for availability.
What documentation comes with a selenium dioxide order?
Each order includes a Certificate of Analysis (CoA), Safety Data Sheet (SDS), and a Material Safety & Handling Guide for compliance and safety.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.