Material Safety Data Sheet for L-Selenomethionine

Identification

Product Name: L-Selenomethionine
Chemical Name: Selenomethionine
CAS Number: 3211-76-5
Synonyms: L-2-Amino-4-(methylselanyl)butanoic acid
Recommended Use: Laboratory chemicals, nutrition supplements, research and development
Supplier Details: Manufacturer and import contact information: address and emergency contact number
Emergency Phone: Chemtrec 24-hour emergency line

Hazard Identification

Classification: Acute Toxicity (Oral) Category 2, Acute Toxicity (Dermal) Category 3, Acute Toxicity (Inhalation) Category 2
Label Elements: Skull and Crossbones pictogram, Danger signal word
Hazard Statements: Fatal if swallowed or inhaled, Toxic in contact with skin
Precautionary Statements: Avoid breathing dust, wash hands thoroughly, use only outdoors or in well-ventilated area, wear protective gloves/protective clothing/eye protection/face protection
Other Hazards: No evidence for significant environmental persistence or bioaccumulation, but seleno-compounds show significant acute aquatic effects at moderate levels

Composition / Information on Ingredients

Chemical Name: L-Selenomethionine
Synonyms: Selenomethionine
Molecular Formula: C5H11NO2Se
Molecular Weight: 196.11 g/mol
Impurities/Additives: Trace moisture, less than 0.1% other organic or inorganic contaminants
Concentration: 98-100% L-Selenomethionine in pure form

First Aid Measures

General: Remove from exposure and provide fresh air
Inhalation: Move person to fresh air, ensure breathing and perform CPR or artificial respiration if necessary; seek immediate medical attention
Skin Contact: Remove contaminated clothing, rinse skin with soap and water for at least 15 minutes; seek medical assistance
Eye Contact: Immediately rinse eyes with large quantities of water, remove contact lenses if present; continue rinsing and seek ophthalmologist evaluation
Ingestion: Do not induce vomiting, do not give liquids except under direct medical supervision; get immediate medical care
Symptoms/Effects: Symptoms may include metallic taste, garlic breath, irritability, nausea, stomach upset, drowsiness, dizziness, and in severe cases, convulsions or death

Fire-Fighting Measures

Suitable Extinguishing Media: Water spray, alcohol-resistant foam, dry chemical, or carbon dioxide for small fires
Specific Hazards: Selenium compounds release toxic fumes under fire conditions (selenium oxides, nitrogen oxides, carbon monoxide, carbon dioxide)
Protective Equipment: Wear self-contained breathing apparatus and full protective gear
Hazardous Combustion Products: Selenium dioxide, oxides of nitrogen
Firefighting Instructions: Evacuate area, do not allow water runoff to contaminate sewers or waterways

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, use suitable personal protective equipment (PPE), avoid dust formation
Environmental Precautions: Prevent further leakage or spillage, do not discharge into drains or environment
Cleanup Methods: Collect spilled material with inert absorbent, shovel into suitable container and seal tightly, ventilate area and wash spill site after material pickup is complete
Reference to Other Sections: For PPE and waste disposal, consult Sections 8 and 13

Handling and Storage

Precautions: Use under chemical hood, minimize dust generation, avoid inhalation or ingestion, never eat, drink, or smoke while handling
Safe Handling: Use PPE including gloves, laboratory coats, goggles, and dust masks/appropriate respirators
Storage Conditions: Store tightly closed in a cool, dry, and well-ventilated area, away from incompatible substances such as strong oxidizers or reducing agents
Recommended Packaging: Airtight containers, shatterproof bottles, secondary containment for added security
Incompatibilities: Avoid direct sunlight, moisture, or extreme changes in temperature

Exposure Controls and Personal Protection

Exposure Limits: No occupational exposure limits established for L-Selenomethionine; recommended limit for selenium compounds: 0.2 mg/m³ (OSHA/ACGIH)
Appropriate Engineering Controls: Chemical fume hood, local exhaust ventilation
Personal Protective Equipment: Nitrile or rubber gloves, chemical safety goggles, laboratory coats, certified respirator if airborne dusts or fumes may be generated
Hygiene Measures: Wash hands, arms, and face thoroughly after working with compound, do not take contaminated clothing home, regular medical check-ups for high-exposure scenarios

Physical and Chemical Properties

Physical State: Crystalline powder
Color: White to off-white
Odor: Slight characteristic sulfur/garlic-like odor
Melting Point: 265°C
Boiling Point: Not determined
Solubility: Slightly soluble in water
pH: Not applicable (solid substance)
Vapor Pressure: Negligible
Density: 1.32 g/cm³ at 20°C
Other characteristics: Stable under ordinary conditions, may decompose at higher temperatures producing toxic fumes

Stability and Reactivity

Chemical Stability: Stable at room temperature in closed containers
Conditions to Avoid: Excessive heat, open flames, moisture, strong acids, and bases
Materials to Avoid: Strong oxidizing agents, strong acids
Hazardous Decomposition Products: Selenium dioxide, oxides of nitrogen, and other toxic gases
Hazardous Reactions: No hazardous polymerization anticipated
Corrosiveness: Not classified as corrosive to metals or tissue under recommended handling

Toxicological Information

Acute Toxicity: Oral LD50 in rats estimated at about 15 mg/kg, significantly more toxic in comparison with standard amino acids
Effects of Exposure: Central nervous system symptoms, nausea, vomiting, garlic odor on breath, headache, drowsiness
Chronic Toxicity: Long-term exposure linked with selenosis: brittle hair and nails, gastrointestinal trouble, neurological effects
Carcinogenicity: Not listed by IARC, NTP, or OSHA as a human carcinogen
Reproductive Toxicity: No adequate data in humans, animal studies show teratogenic effects at high exposures
Routes of Entry: Inhalation, ingestion, skin absorption
Sensitization: Not established in humans or animals

Ecological Information

Aquatic Toxicity: Toxic to aquatic life; LC50 (Rainbow trout) less than 1 mg/L
Mobility in Soil: Tends to bind to soil components, but selenium can leach into water systems depending on physical-chemical properties of local soil
Persistence and Degradability: Not readily biodegradable, may undergo slow microbial transformation
Bioaccumulation Potential: Selenium compounds can accumulate in food chains, posing risk to aquatic and terrestrial organisms
Environmental Fate: May lead to selenium bioaccumulation in plants and animals, especially at levels above natural background concentrations
Other Adverse Effects: No ozone depletion, photochemical ozone creation, or endocrine disruption evidence reported for this compound

Disposal Considerations

Waste Treatment Methods: Dispose of contents/container in accordance with local, regional, national, and international regulations
Container Disposal: Triple-rinse containers, render non-reusable, deliver to licensed hazardous waste disposal contractor
Precautions: Do not allow to enter groundwater, surface water, or sewage system
Recommended Disposal Route: Incineration or hazardous waste landfill for selenium-containing compounds, following all appropriate permit requirements

Transport Information

UN Number: 3288
UN Proper Shipping Name: Toxic Solid, Inorganic, N.O.S. (L-Selenomethionine)
Transport Hazard Class: 6.1 (Toxic substance)
Packing Group: II
Marine Pollutant: Yes (according to IMDG)
Special Precautions for User: Proper labeling, documentation, packaging, and declaration as dangerous goods required
Regulatory Requirements: Comply with all transport guidance based on chosen route and destination (ADR, IMDG, IATA, RID regulations)

Regulatory Information

TSCA Inventory: Listed
REACH Registration: Exempt or covered by exemption under Annex IV/V for use as a research chemical
OSHA Hazard Communication: Acute Toxicity Category 2/3/2
SARA Section 313: Covered (selenium compounds)
California Proposition 65: Not listed
WHMIS Classification (Canada): D1A (very toxic material causing immediate and serious toxic effects)
Other Labelling: Ensure safe handling information clearly posted and training provided
International Inventory Status: Meets registration or notification requirements in major jurisdictions