Material Safety Data Sheet for Selenomethionine

Identification

Product Name: Selenomethionine
Chemical Name: 2-Amino-4-(methylselanyl)butanoic acid
CAS Number: 3211-76-5
Molecular Formula: C5H11NO2Se
Molecular Weight: 196.11 g/mol
Synonyms: L-Selenomethionine, Seleno-L-methionine
Recommended Use: Laboratory reagents, dietary supplements, research applications
Manufacturer/Supplier: Refer to product label or purchase order
Emergency Phone Number: Contact local poison center or emergency response service

Hazard Identification

GHS Classification: Acute Toxicity (Oral) – Category 2; Eye Irritation – Category 2A; Skin Sensitization – Category 1
Signal Word: Danger
Hazard Statements: Toxic if swallowed. Causes serious eye irritation. May cause allergic skin reaction.
Pictograms: Skull and crossbones, exclamation mark
Precautionary Statements: Wash hands after handling. Keep container tightly closed. Avoid breathing dust. Do not eat, drink, or smoke when using this product.
Routes of Exposure: Inhalation, ingestion, skin, and eyes
Target Organs: Liver, kidneys, nervous system
Potential Health Effects: Acute symptoms include nausea, vomiting, abdominal pain, headache, and dizziness. Chronic exposure may cause selenosis, fatigue, irritability, and garlic breath odor.

Composition / Information on Ingredients

Component: Selenomethionine
Chemical Formula: C5H11NO2Se
CAS Number: 3211-76-5
Concentration: >98% by weight
Impurities: Trace organic and inorganic contaminants may be present at <2%. No significant hazardous impurities expected at these concentrations.

First Aid Measures

Inhalation: Move affected person to fresh air. Provide oxygen if breathing becomes difficult. Seek medical attention.
Skin Contact: Wash thoroughly with soap and water. Remove contaminated clothing. If irritation develops, get medical help.
Eye Contact: Rinse with water for at least 15 minutes, lifting eyelids occasionally. Seek prompt medical attention.
Ingestion: Rinse mouth with water. Do not induce vomiting unless directed by medical personnel. Get medical help immediately.
Note to Physicians: Treat symptomatically. Monitor for selenium toxicity. Support respiratory and cardiovascular systems as needed.

Fire-Fighting Measures

Suitable Extinguishing Media: Use water spray, dry chemical powder, foam, or carbon dioxide extinguishers.
Hazardous Combustion Products: Selenium oxides, nitrogen oxides, carbon monoxide, carbon dioxide
Special Protective Equipment: Firefighters require self-contained breathing apparatus and full protective gear.
Fire and Explosion Hazards: Product dust can form explosive mixtures with air. Toxic dust and fumes may result from combustion.
Advice for Firefighters: Isolate fire area. Use water spray to cool exposed containers. Avoid inhalation of combustion residues.

Accidental Release Measures

Personal Precautions: Restrict entry to spill area. Use personal protective equipment: gloves, goggles, lab coat, and suitable respiratory protection.
Environmental Precautions: Prevent run off to sewers, surface, and ground water. Notify authorities if contamination occurs.
Methods for Cleaning Up: Sweep up (avoid dust formation) and place in a suitable closed container for disposal. Ventilate the area and wash spill site after cleanup.
Containment: Use inert absorbent material for spills of solutions.

Handling and Storage

Safe Handling: Work in a well-ventilated area. Minimize dust production. Avoid ingestion, inhalation, and contact with skin or eyes.
Hygiene Practices: Wash thoroughly after handling. Remove contaminated clothing before entering eating areas.
Storage Conditions: Store in a cool, dry, well-ventilated area, away from incompatible substances such as strong oxidizers and acids.
Container Requirements: Keep container tightly closed. Use chemical-grade containers made of compatible materials.
Incompatibilities: Strong oxidizing agents, strong acids

Exposure Controls and Personal Protection

Engineering Controls: Use fume hood or local exhaust ventilation to minimize exposure.
Occupational Exposure Limits: OSHA PEL (selenium compounds, as Se): 0.2 mg/m³ (TWA); ACGIH TLV: 0.2 mg/m³ (TWA)
Personal Protective Equipment: Respiratory protection (NIOSH approved), chemical safety goggles, lab coat, and chemical resistant gloves (nitrile or neoprene)
Hygiene Measures: Avoid eating, drinking, or smoking during use. Wash hands before breaks and after use.
Environmental Controls: Prevent release to environment by proper waste collection and ventilation.

Physical and Chemical Properties

Appearance: White to off-white crystalline powder
Odor: Mild, may have slight metallic or garlic odor
Odor Threshold: Not determined
pH: Approximately 4.5 (1% aqueous solution)
Melting Point: 265–267°C (decomposes)
Boiling Point: Not applicable (decomposes)
Flash Point: Not flammable
Evaporation Rate: Not applicable
Flammability: Non-flammable solid
Vapor Pressure: Not applicable
Vapor Density: Not applicable
Solubility: Soluble in water (approx. 20 mg/mL at room temperature), insoluble in organic solvents
Partition Coefficient (log Kow): Not available
Auto-Ignition Temperature: Not applicable
Decomposition Temperature: >265°C
Viscosity: Not applicable

Stability and Reactivity

Chemical Stability: Stable under recommended storage and handling conditions
Reactivity: No hazardous reactions expected under normal conditions
Incompatible Materials: Strong oxidizing agents, acids
Hazardous Decomposition Products: Selenium oxides, carbon monoxide, carbon dioxide, nitrogen oxides
Polymerization: Will not occur
Conditions to Avoid: High temperature, moisture, exposure to incompatible materials

Toxicological Information

Acute Toxicity: Oral LD50 (rat): 25–30 mg/kg. Toxic by ingestion.
Chronic Toxicity: Long-term exposure can result in selenosis (selenium poisoning), symptoms include gastrointestinal disturbances, hair loss, nail brittleness, fatigue, and neurological abnormalities.
Skin Contact: May cause mild irritation or skin sensitization.
Eye Contact: Causes eye irritation.
Inhalation: Inhalation of dust or aerosol may lead to respiratory tract irritation and systemic toxicity.
Carcinogenicity: No classification by IARC, NTP, or OSHA. Some evidence of potential cancer risk at very high doses in animals.
Mutagenicity: No significant data in humans.
Reproductive Toxicity: High exposures may interfere with fertility and development.
Target Organs: Liver, kidneys, nervous system
Signs and Symptoms: Metallic taste, garlic odor on breath, skin rash, loss of hair, abnormal nail growth

Ecological Information

Ecotoxicity: Selenium compounds can bioaccumulate in aquatic organisms, potentially toxic to fish, aquatic invertebrates, and plants.
Persistence and Degradability: Relatively persistent, low degradation rate in soil and water.
Bioaccumulative Potential: High bioaccumulation reported in aquatic environments.
Mobility in Soil: Moderate mobility depending on soil properties and pH.
Other Adverse Effects: Releases into the environment can result in selenium poisoning in wildlife and contamination of waterways.

Disposal Considerations

Waste Treatment Methods: Dispose of via licensed chemical waste contractor, in accordance with local, regional, and national regulations.
Product Disposal: Do not dispose in regular trash or sewer. Use approved chemical waste disposal.
Contaminated Packaging: Rinse carefully before reuse or recycling; otherwise, dispose as hazardous waste.
Regulatory Requirements: Adhere to all local, state, and national hazardous waste and environmental regulations.
Special Precautions for Landfill or Incineration: Only certified hazardous waste facilities should be used to prevent environmental contamination.

Transport Information

UN Number: UN3283
UN Proper Shipping Name: Selenium compounds, n.o.s. (not otherwise specified)
Transport Hazard Class: 6.1 (Toxic substances)
Packing Group: II
Label: Toxic
Marine Pollutant: Yes (selenium compounds)
Special precautions for user: Keep container upright and tightly closed. Avoid release to environment during transport.
Regulatory References: Comply with DOT, IATA, IMDG regulations.

Regulatory Information

TSCA Inventory: Listed in the United States TSCA inventory
EINECS/ELINCS: Listed (218-700-8)
REACH Registration Number: Refer to supplier for registration status
OSHA Hazardous Chemical: Yes
SARA 313: Selenium compounds reportable under Section 313
CERCLA: Reportable Quantity (RQ) for selenium is 1 pound
California Proposition 65: Not listed as a known carcinogen or reproductive toxin
WHMIS Canada: Toxic Material; D1A, D2B
Other local, state, and international regulations: Ensure full compliance for storage, use, transportation, and disposal