Osmium Tetroxide
- CAS Number
- 20816-12-0
- HSN Code
- 28439019
- Molecular Formula
- OsO4
- Catalogue Number
- AL3358
- Purity
- ≥ 99.9%
- Molecular Weight
- 254.23 g/mol
Complies with : IP | BP | USP | EP | ACS
ISO 9001
ISO 14001
GMP
COA with every batch
Key Properties
Osmium tetroxide is an osmium coordination entity consisting of four oxygen atoms bound to a central osmium atom via covalent double bonds. It has a role as a NMR chemical shift reference compound, a fixative, an oxidising agent, a poison and a histological dye.
Also known as Osmic acid.
- Catalogue No.
- AL3358
- CAS Number
- 20816-12-0
- Molecular Formula
- OsO4
- Molecular Weight
- 254.23 g/mol
- HSN Code
- 28439019
- Grade
- AR (Analytical Reagent)
- Product Form
- Substance
Melting point: 40.6 °C; Boiling point: 130.0 °C at 760 mm Hg; begins to sublime and distill well below bp; Density: 5.10 (Calculated).
- Appearance
- Pale yellow solid; monoclinic crystals
- Shelf Life
- -
- Packaging
- Available in: 1 gm glass bottle, 10 gm glass bottle
- Storage
- Separated from combustible substances, reducing agents and food and feedstuffs. Ventilation along the floor.
1.1 — Product identifier
- Chemical Name
- Osmium Tetroxide
- Catalogue No.
- AL3358
- Product form
- Substance
- CAS Number
- 20816-12-0
- EC Number
- 244-058-7
- Grade
- AR
- EC Index Number
- Not specified
- Chemical Formula
- OsO4
- HSN Code
- 28439019
- Synonyms
- Osmic acid
1.2 — Relevant identified uses of the substance or mixture and uses advised against
- Use of the substance/mixture
- Fixative and stain in electron microscopy
- Uses advised against
- Not specified
1.3 — Details of the supplier of the safety data sheet
- Company identification
- Address:- 102, B wing, Savgan Heights, RTO Lane,Andheri (W), Mumbai-400 053Maharashtra, India.
1.4 — Emergency Contact Details
- Phone / e-Mail
- Phone : +91 22 26317055 Mobile : +91 9820385757 e-mail : info@alphachemika.co.in
2.1 — Classification of the substance or mixture
- Classification according to Regulation (EC) No 1272/2008
- Acute Tox. 2; Acute Tox. 1; Skin Corr. 1B; Resp. Sens. 1
- Classification source
- ECHA C&L Inventory via PubChem CID 30318 - hazard classes notified by at least 50% of companies; pictograms and signal word derived from those statements
2.2 — Label elements
- Hazard pictograms
- Corrosive, Acute Toxic, Health Hazard
- Signal word
- Danger
- Hazard statements
- H300: Fatal if swallowed; H310: Fatal in contact with skin; H314: Causes severe skin burns and eye damage; H330: Fatal if inhaled; H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled
- Precautionary statements
- P233, P260, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P342+P316, P361+P364, P363, P403, P403+P233, P405, P501
2.3 — Other hazards
- Other hazards
- Extremely toxic; may cause severe eye and respiratory tract damage.
3.1 — Substance
- Name
- Osmium Tetroxide
- CAS No.
- 20816-12-0
4.1 — Description of first aid measures
- First-aid measures after inhalation
- If this chemical has been inhaled, remove the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the person warm and at rest.
- First-aid measures after skin contact
- If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.
- First-aid measures after eye contact
- If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.
- First-aid measures after ingestion
- If this chemical has been swallowed, get medical attention immediately.
4.2 — Most important symptoms and effects, both acute and delayed
- Symptoms relating to use
- Severe respiratory distress, eye damage, skin irritation.
4.3 — Indication of any immediate medical attention and special treatment needed
- General information
- Treat symptomatically. Show this safety data sheet to the treating physician.
5.1 — Extinguishing media
- Suitable extinguishing media
- Water spray, carbon dioxide, dry chemical powder, foam.
- Unsuitable extinguishing media
- Not specified
5.2 — Special hazards arising from the substance or mixture
- Special procedures
- Reacts violently with organic materials; use appropriate extinguishing media.
5.3 — Advice for firefighters
- Protection during firefighting
- Do not enter fire area without proper protective equipment, including respiratory protection.
6.1.1 — For non-emergency personnel
- Emergency procedures
- Evacuate area; ventilate; use appropriate PPE.
6.3 — Methods and material for containment and cleaning up
- Methods for cleaning up
- Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers.
6.4 — Reference to other sections
- Reference
- Not specified
7.1 — Precautions for safe handling
- Precautions for safe handling
- Use in a fume hood; wear appropriate PPE including gloves and goggles.
- Hygiene measures
- Wash hands and other exposed areas with mild soap and water before eating, drinking or smoking and when leaving work.
7.2 — Conditions for safe storage, including any incompatibilities
- Storage conditions
- Separated from combustible substances, reducing agents and food and feedstuffs. Ventilation along the floor.
8.2 — Exposure controls
- Hand protection
- Protective gloves (e.g. nitrile rubber)
- Eye protection
- Chemical safety goggles or safety glasses
- Skin and body protection
- Wear suitable protective clothing
- Respiratory protection
- Use NIOSH-approved respirator if exposure limits are exceeded.
9.1 — Information on basic physical and chemical properties
- Physical state
- Solid
- Colour
- Pale yellow to golden
- Odour
- Acrid, chlorine-like odor
- Odour threshold
- Not specified
- pH value
- Not applicable
- Relative evaporation rate (butylacetate=1)
- Not specified
- Melting point
- 40.6 °C
- Freezing point
- Not specified
- Boiling point
- 130.0 °C at 760 mm Hg; begins to sublime and distill well below bp
- Flash point
- Not applicable
- Auto-ignition temperature
- Not applicable
- Decomposition temperature
- Not specified
- Flammability (solid, gas)
- Not flammable
- Vapour pressure
- 11 mm Hg at 27 °C
- Relative vapour density at 20°C
- Relative vapor density (air = 1): 8.8
- Density
- 5.10 (Calculated)
- Solubility
- Soluble in water, alcohol, and ether
- Log Pow
- Not specified
- Viscosity, kinematic
- Not applicable
- Viscosity, dynamic
- Not specified
- Explosive properties
- Not explosive
- Oxidising properties
- Strong oxidizer
- Explosive limits
- Not applicable
10.1 — Reactivity
- Reactivity
- Reacts violently with organic materials and reducing agents.
10.2 — Chemical stability
- Chemical stability
- Readily vaporizes from aqueous solution even at room temperature.
10.3 — Possibility of hazardous reactions
- Possibility of hazardous reactions
- Decomposes on heating. This produces fumes of osmium. The substance is a strong oxidant.
10.4 — Conditions to avoid
- Conditions to avoid
- Avoid contact with incompatible materials and excessive heat.
10.5 — Incompatible materials
- Incompatible materials
- Strong reducing agents, organic materials, and bases.
10.6 — Hazardous decomposition products
- Hazardous decomposition products
- When heated to decomposition, it emits toxic fumes of osmium.
11.1 — Information on toxicological effects
- Acute toxicity
- LD50 Mouse oral 162 mg/kg; LD50 Rat ip 14.1 mg/kg; LD50 Mouse ip 13.5 mg/kg
- Skin corrosion/irritation
- H314: Causes severe skin burns and eye damage
- Serious eye damage/irritation
- Not classified (based on available data)
- Respiratory or skin sensitisation
- H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled
- Germ cell mutagenicity
- Not classified (based on available data)
- Carcinogenicity
- Not classified (based on available data)
- Specific target organ toxicity (single exposure)
- Not classified (based on available data)
- Specific target organ toxicity (repeated exposure)
- Not classified (based on available data)
12.1 — Toxicity
- Toxicity information
- Not specified
12.2 — Persistence - degradability
- Persistence - degradability
- Not specified
12.3 — Bioaccumulative potential
- Bioaccumulative potential
- Not specified
12.4 — Mobility in soil
- Mobility in soil
- Not specified
12.6 — Other adverse effects
- Environmental precautions
- Not specified
13.1 — Waste treatment methods
- Additional Info
- Dispose of contents/container in accordance with local, regional, national and international regulations.
14.1 — UN number
- UN-No. (ADR)
- UN 2471
- UN-No. (IMDG)
- UN 2471
- UN-No. (IATA)
- UN 2471
- UN-No. (ADN)
- UN 2471
- UN-No. (RID)
- UN 2471
14.2 — UN proper shipping name
- Proper Shipping Name (ADR)
- Osmium Tetroxide
- Proper Shipping Name (IMDG)
- Osmium Tetroxide
- Proper Shipping Name (IATA)
- Osmium Tetroxide
- Proper Shipping Name (ADN)
- Osmium Tetroxide
- Proper Shipping Name (RID)
- Osmium Tetroxide
14.3 — Transport hazard class(es)
- Transport hazard class(es)
- 6.1
14.4 — Packing group
- Packing group (ADR)
- I
- Packing group (IMDG)
- I
- Packing group (IATA)
- I
- Packing group (ADN)
- I
- Packing group (RID)
- I
14.5 — Environmental hazards
- Dangerous for the environment
- Not specified
- Marine pollutant
- Not specified
- Other information
- No supplementary information available
15.1 — Safety, health and environmental regulations/legislation specific for the substance or mixture
- 15.1.1 EU-Regulations
- Not specified
Chief laboratory use of osmium tetroxide is as a biological stain for adipose tissues in histopathological laboratories.
ISO 9001
ISO 14001
GMP
COA with every batch
- Batch Number
- AL-2026-AL1125A
- Manufacturing Date
- September-2026
- Expiry Date
- September-2031
- Molecular Weight
- 254.23 g/mol
| Test | Standard | Observed |
|---|---|---|
| Assay | ≥ 99.9% | 99.95% |
| Melting Point | -12.0 °C | -12.0 °C |
| Moisture Content | ≤ 0.5% | 0.3% |
| Residue on Ignition | ≤ 0.1% | 0.05% |
| Related Substances | None detected | None detected |
The above product is expected to comply with AR grade specification.
Technical Data Sheet
| Grade | Assay/Purity | Melting/Boiling Point | Moisture/LOD | Residue on Ignition | Related Substances | Solubility |
|---|---|---|---|---|---|---|
| 99.9% AR | ≥ 99.9% | m.p. 40.6 °C; b.p. 130.0 °C at 760 mm Hg; begins to sublime and distill well below bp | ≤ 0.5% | ≤ 0.1% | None detected | Soluble in water, alcohol, and ether |
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