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Product Name: Hydrogen Selenide, Anhydrous
Chemical Formula: H2Se
Synonyms: Hydroselenic acid, Selenium hydride
CAS Number: 7783-07-5
Recommended Use: Semiconductor industry, research laboratories, chemical synthesis
Manufacturer Contact Information: [Company name, emergency contact number, address, email]
Emergency Phone Number: [Emergency phone number for chemical incidents]
Classification: Flammable gas, Acute toxicity (inhalation), Environmental hazard
Signal Word: Danger
Hazard Statements: Extremely toxic if inhaled; Fatal in contact with skin; Causes respiratory irritation; Flammable; Hazardous to aquatic life
Precautionary Statements: Do not breathe gas; Wear respiratory protection; Avoid release to the environment; Keep away from heat, sparks, and open flames; No smoking
Pictograms: Skull and crossbones, flame, exclamation mark, environment
Routes of Exposure: Inhalation, skin contact, eye contact
Target Organs: Central nervous system, respiratory system, cardiovascular system
Chemical Name: Hydrogen Selenide
Synonyms: Selenium hydride
CAS Number: 7783-07-5
Concentration: 100% (anhydrous gas)
Impurities: May contain trace amounts of elemental selenium or moisture
General Advice: Get immediate medical attention. Move victim to fresh air without delay.
Inhalation: Remove from exposure and keep patient warm and still. Provide oxygen if breathing is difficult. Artificial respiration if not breathing. Immediate hospitalization required.
Skin Contact: Remove contaminated clothing. Flush skin with large amounts of water for at least 15 minutes. Seek prompt medical evaluation.
Eye Contact: Rinse thoroughly with water for at least 15 minutes. Lift eyelids occasionally. Obtain medical aid immediately.
Ingestion: Not considered a likely route due to gaseous state; if exposure suspected, seek medical attention.
Medical Attention/Special Treatment: Provide symptomatic and supportive care; monitor for pulmonary edema, cardiac arrhythmias, and CNS depression.
Suitable Extinguishing Media: Use dry chemical, CO2, or water spray for small fires involving nearby combustibles. Hydrogen selenide may form explosive mixtures with air.
Specific Hazards: Highly flammable, reacts to form toxic selenium compounds upon combustion; fire produces corrosive and toxic gases (selenium dioxide and hydrogen selenide).
Protective Equipment for Firefighters: Full protective gear and self-contained breathing apparatus (SCBA) are essential. Approach from upwind.
Special Instructions: Evacuate area. Cool containers with water spray if safe. Do not allow water runoff to enter drains or water supply.
Unusual Fire/Explosion Hazards: Forms explosive mixtures with air between 4.3%–30% by volume. Vapors heavier than air; accumulate in low spaces.
Personal Precautions: Evacuate personnel, ventilate area, and isolate hazard zone. Wear gas-tight chemical suit and self-contained breathing apparatus.
Spill Response: Shut off leaks if safe. Use water spray to knock down vapors. Prevent entry into confined spaces.
Environmental Precautions: Prevent from entering sewers, basements, or confined areas. Notify environmental authorities if large quantities are released.
Cleanup Methods: Ventilate; neutralize with sodium hypochlorite or sodium carbonate solution if feasible. Collect all residues and dispose of as hazardous waste.
Decontamination: Remove contaminated clothing and wash thoroughly before reuse.
Handling: Only trained personnel should handle cylinders. Avoid inhalation and direct contact. Work in a fume hood with properly functioning gas detection equipment. Use non-sparking tools and explosion-proof equipment.
Storage: Store in tightly closed, approved gas cylinders. Secure upright and protect from physical damage and heat sources. Label clearly. Store away from oxidizers, acids, and flammable materials. Maintain temperature below 52°C (125°F).
Further Protection: Keep emergency equipment available, including respiratory protection, eye wash stations, and deluge showers.
Occupational Exposure Limits: OSHA PEL: 0.05 ppm (Ceiling); NIOSH REL: 0.05 ppm (Ceiling); ACGIH TLV: 0.05 ppm (Ceiling).
Engineering Controls: Use closed systems and local exhaust ventilation. Install gas detection alarms and explosion-proof equipment.
Personal Protective Equipment: Full-face supplied-air respirator or self-contained breathing apparatus for emergency response. Wear protective gloves, chemical-resistant suit, and safety goggles.
Hygiene Practices: Wash hands, forearms, and face thoroughly after handling; avoid eating, drinking, or smoking while working with this material.
Monitoring Requirements: Continuous gas detection monitoring required in work areas.
Appearance: Colorless gas
Odor: Decayed horseradish or garlic at low concentrations, quickly desensitizing to odor detection
Odor Threshold: Approximately 0.1 ppm
pH: Not applicable (gas)
Melting Point: -64 °C
Boiling Point: -41 °C
Flash Point: Not applicable; highly flammable gas
Flammability: Flammable, explosive range in air: 4.3–30% by volume
Vapor Pressure: 2,000 mm Hg at 20 °C
Vapor Density: 2.85 (air=1)
Solubility: Slightly soluble in water (3.9 mL/100 mL H2O)
Molecular Weight: 80.98 g/mol
Partition Coefficient: Not available
Auto-ignition Temperature: 210 °C
Decomposition Temperature: Decomposes above 250 °C to selenium and hydrogen
Evaporation Rate: Not applicable
Chemical Stability: Unstable in presence of heat, sparks, open flames; decomposes to selenium and hydrogen when heated.
Reactivity: May react violently with strong oxidizers, halogens, acids; forms explosive mixtures with air.
Hazardous Reactions: Combines rapidly with oxygen; decomposes to toxic elements upon burning.
Hazardous Decomposition Products: Selenium, hydrogen, selenium dioxide.
Conditions to Avoid: Heat, static discharge, incompatible materials, direct sunlight, moisture.
Incompatible Materials: Metals, oxidizing agents, acids, bases, halogens.
Acute Toxicity: LC50 (rat, inhalation, 1 hour): 1.5 ppm; extremely toxic; human fatalities reported at very low concentrations.
Delayed/Chronic Effects: Prolonged exposure may cause central nervous system effects, respiratory distress, bronchitis, pulmonary edema. Selenium may accumulate in body.
Symptoms of Exposure: Dizziness, headache, nausea, vomiting, metallic taste, respiratory irritation, weakness, convulsions, paralysis, possible death from respiratory failure.
Carcinogenicity: IARC: Not classifiable; ACGIH: Not listed; Selenium compounds classified differently.
Other Effects: May cause garlic breath odor, dermatitis, photosensitivity, gastrointestinal symptoms.
Sensitization: Not established.
Target Organs: Lungs, central nervous system, cardiovascular system, kidneys.
Aquatic Toxicity: Highly toxic to aquatic organisms; even small releases pose environmental hazards.
Persistence and Degradability: Not readily biodegradable. Selenium can accumulate in soils and sediments.
Bioaccumulation Potential: Potential for bioaccumulation in aquatic environments; selenium compounds persistent in ecosystem.
Mobility in Soil: Forms soluble selenium compounds, which may migrate through soil and contaminate water supplies.
Other Information: Avoid contamination of waterways; report significant releases to environmental authorities.
Waste Handling: Hydrogen selenide is a hazardous material. Neutralize with oxidizing agents before disposal. Do not release to environment.
Container Precautions: Return empty cylinders to supplier after proper neutralization and purging.
Recommended Disposal Method: Neutralize with sodium hypochlorite or alkali scrubbers; contact licensed hazardous waste disposal service.
RCRA Status: Listed as hazardous waste. Disposal must meet local, state, and federal regulations.
Environmental Precautions: Avoid discharge into drains, soils, or surface water.
UN Number: UN 2202
Proper Shipping Name: Hydrogen selenide, compressed
Hazard Class: 2.3 (Toxic gas); subsidiary risk 2.1 (Flammable gas)
Packing Group: NA (compressed gas)
Labeling Requirements: Toxic gas, flammable gas
Special Provisions: Emergency response guidance for transport incidents required. Cylinders must be adequately secured and protected from physical damage during transport.
Transport Emblems: Skull and crossbones, flame
Environmental Hazards: Marine pollutant; strictly regulate shipments near water bodies.
Additional Information: Strict adherence to DOT, IATA, and IMDG regulations for packaging and handling.
OSHA: Regulated hazardous substance (29 CFR 1910.1000).
EPA: Listed as hazardous air pollutant; subject to reporting under SARA Title III, Section 302 and 313.
TSCA: Listed in the Toxic Substances Control Act inventory.
CERCLA: Designated as hazardous substance; reportable quantity 1 lb (0.454 kg).
State Regulations: Subject to right-to-know reporting in many states; California Proposition 65 does not list hydrogen selenide, but selenium compounds are addressed.
International: Complies with EU REACH, CLP, and GHS labels; includes restriction and notification requirements.
Workplace Labelling: GHS labels mandatory; provide hazard information, emergency measures, and supplier identification.
Other Guidance: Ensure ongoing training and certification of workers; regularly update MSDS in accordance with local laws and international standards.
