Material Safety Data Sheet (MSDS): L-Se-Methylselenocysteine

Identification

Product Name: L-Se-Methylselenocysteine
Chemical Formula: C4H9NO2Se
Synonyms: Selenomethionine methyl derivative, SeMCys
CAS Number: 1464-34-8
Manufacturer: Supplied by various chemical and biotechnology suppliers
Recommended Use: Research applications, dietary supplement ingredient
Contact: Address, phone, and emergency number available from direct supplier source

Hazard Identification

Emergency Overview: White to off-white crystalline powder, can emit selenium-related odors
Classification: Acute oral toxicity (Category 3), Eye irritation (Category 2A), Skin irritation (Category 2)
Health Hazards: Toxic if ingested or inhaled; can cause nausea, vomiting, abdominal pain
Environmental Hazards: Hazardous to aquatic organisms and may cause long-term adverse effects in the aquatic environment
Label Elements: GHS skull and crossbones, irritant, environmental hazard icons
Signal Word: Danger
Precautionary Statements: Avoid breathing dust, use personal protective equipment, wash thoroughly after handling

Composition / Information on Ingredients

Chemical Name: L-Se-Methylselenocysteine
Purity: >95%
Impurities: Trace solvent or manufacturing byproducts, testing confirms <0.5% uncharacterized material
Hazardous Components: No other hazardous components above threshold limits identified

First Aid Measures

Inhalation: Remove victim to fresh air, provide oxygen if breathing is difficult, seek medical attention if symptoms develop or persist
Skin Contact: Remove contaminated clothing, rinse skin with soap and plenty of water for at least 15 minutes, medical evaluation if redness or irritation occurs
Eye Contact: Rinse eyes immediately with large amounts of water, lifting eyelids to ensure thorough flushing; obtain medical help promptly
Ingestion: Do not induce vomiting unless instructed by medical personnel, rinse mouth, get medical attention quickly if large amounts ingested or any symptoms occur
Most Important Symptoms: Burning sensation, cough, dizziness, malaise, gastrointestinal discomfort, possible toxic effects from selenium exposure
Self-Protection for First Aiders: Use personal protective equipment, avoid contact, ensure adequate ventilation

Fire-Fighting Measures

Suitable Extinguishing Media: Water spray, dry chemical, carbon dioxide, foam
Specific Hazards: Combustion can produce toxic selenium oxides and other hazardous fumes
Protective Equipment for Firefighters: Full protective gear, positive pressure self-contained breathing apparatus
Special Procedures: Contain runoff using barriers or diking, avoid water contamination
Fire/Explosion Risk: Dust may form explosive mixtures with air under intense heat

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, don suitable protective equipment, ventilate area
Environmental Precautions: Prevent further leakage or spillage if safe to do so, avoid entry into drains, sewers or natural water bodies
Methods for Clean-up: Sweep or scoop up without generating dust, place in properly labeled, tightly closed container for disposal, use non-sparking tools
Decontamination: Wash spill site with plenty of water once material is removed
Notification: Contact local environmental or safety authorities if large quantity released

Handling and Storage

Handling: Perform operations in controlled atmosphere, avoid generation of dust or aerosols, use local exhaust ventilation
Storage: Keep tightly sealed in original container, store at 2–8°C in a dry, well-ventilated, secure facility; protect from light and sources of ignition
Incompatible Materials: Strong oxidizing agents, acids, reducing agents, halogens
Hygiene Measures: Wash hands thoroughly after handling, remove contaminated clothing, clean before reuse

Exposure Controls and Personal Protection

Engineering Controls: Chemical fume hood, local exhaust ventilation, eyewash stations and safety showers in work area
Occupational Exposure Limits: No established ACGIH or OSHA limits for this compound, but keep below general selenium compound threshold of 0.2 mg/m³ (TWA)
Personal Protective Equipment: NIOSH-approved respirator for dusts/fumes, chemical-resistant gloves (nitrile or neoprene), lab coat, safety goggles or face shield, closed-toe shoes
Environmental Exposure: Implement controls to prevent workplace contamination and accidental releases to the environment

Physical and Chemical Properties

Appearance: White to off-white crystalline powder
Odor: Mild, organic
Odor Threshold: No data available
pH: No data for solution, expected neutral to slightly acidic in water
Melting Point: Around 187-190°C (decomposes)
Boiling Point: Not applicable
Solubility: Soluble in water, slightly soluble in ethanol, insoluble in chloroform
Vapor Pressure: Negligible
Density: ~1.64 g/cm³
Partition Coefficient (log Kow): Not measured, likely low due to high polarity
Flash Point: Not flammable under normal handling
Auto-ignition Temperature: No data
Explosive Properties: Dust may pose risk under special conditions
Decomposition Temperature: 187-190°C

Stability and Reactivity

Chemical Stability: Stable under standard laboratory conditions when sealed and stored correctly
Reactivity: Can react with oxidizing agents with vigorous release of gases
Hazardous Reactions: None expected under normal storage, avoid heat, sparks, open flame
Hazardous Decomposition Products: Produces selenium oxides, carbon monoxide, carbon dioxide on combustion
Incompatible Materials: Strong acids, oxidizers, halogens, reducing agents
Polymerization: Will not polymerize spontaneously

Toxicological Information

Acute Toxicity: Oral LD50 (rat): about 10 mg/kg; lower threshold for chronic selenium toxicity in repeated doses
Routes of Exposure: Oral, inhalation, dermal contact, ocular contact
Symptoms: Drowsiness, headache, gastrointestinal upset, garlic breath (typical of selenium toxicity), possible nerve and liver effects at high doses
Chronic Exposure: Can lead to selenosis, which includes hair loss, nail changes, nervous system disturbances
Skin/Eye Effects: Irritation, redness, possible chemical conjunctivitis
Mutagenicity, Carcinogenicity, Reproductive Effects: No evidence for direct mutagenic or carcinogenic effects; selenium compounds at high doses may affect reproductive system
Exposure Limits: No specific workplace limit set; treat as toxic material
Medical Conditions Aggravated by Exposure: Preexisting skin, eye, or respiratory conditions

Ecological Information

Ecotoxicity: Toxic to aquatic invertebrates and fish; selenium compounds can bioaccumulate and disrupt wildlife reproductive cycles
Mobility in Soil: Water-soluble form, migrates through soil and water systems
Persistence and Degradability: Not rapidly degraded; can persist and accumulate in the ecosystem
Bioaccumulation Potential: Selenium compounds bioaccumulate in aquatic food chains
Other Adverse Effects: Small concentrations may be hazardous in sensitive environments

Disposal Considerations

Waste Disposal Methods: Dispose of according to local, state, and federal regulations for hazardous chemical waste; do not release to drains, surface water, or soil
Contaminated Packaging: Dispose in labeled hazardous waste container, rinse thoroughly if possible
Recycling/Recovery: Not feasible for this compound; avoid attempts to neutralize except under expert supervision
EPA Waste Number: U205 or other as required for selenium compounds
Special Precautions: Wear PPE, label and seal all wastes, transport promptly to hazardous waste facility

Transport Information

UN Number: 3288
Proper Shipping Name: Toxic solid, organic, n.o.s. (contains methylselenocysteine)
Transport Hazard Class: 6.1 (toxic substances)
Packing Group: II (medium hazard)
Marine Pollutant: Yes
Special Precautions: Prevent packages from breaking, store away from incompatible goods, inform carrier of toxic substance
Regulatory Requirements: Follows national and international transport standards for hazardous materials

Regulatory Information

OSHA: Regulated under Hazard Communication Standard
TSCA: Notification required for TSCA inventory status, not for consumer use
REACH/CLP (EU): Requires registration/notification for use in Europe, classified toxic
SARA Title III: Subject to reporting due to toxicity and environmental hazard
DSL/NDSL (Canada): Reporting may be required for import or manufacture
Other Regulations: Check with country-specific regulations on use, handling, and disposal
Labeling: Product labeled toxic, environmental dangerous, and with proper hazard pictograms