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Product Name: Ethylene Oxide
Chemical Formula: C2H4O
CAS Number: 75-21-8
Synonyms: Oxirane, 1,2-Epoxyethane
Recommended Uses: Sterilizing medical devices, producing chemicals like ethylene glycol, fumigating spices
Supplier Details: Direct all safety and handling questions to your facility’s authorized chemical supplier. Only trained professionals should contact supplier emergency lines in case of exposure or large releases.
Classification: Flammable gas, carcinogen, mutagen, acute toxicant (Category 1, 2, 3 risks under GHS)
Label Elements: Danger signal word; human icon with star on chest (health hazard); explosion pictogram (gas/flame hazard)
Hazard Statements: Extremely flammable, can cause cancer, suspected of causing genetic defects, fatal if inhaled, causes severe eye and skin irritation, may damage fertility or unborn child
Precautionary Statements: No open flames, sparks, or smoking; shield eyes and skin fully; prevent inhalation; only use outdoors or in a fume hood; keep away from heat and electrical equipment
Ingredient: Ethylene Oxide
Chemical Identity: C2H4O, Ethylene Oxide – 99–100% by weight
Impurities: Minor water, ethylene glycol created by hydrolysis if exposed to moisture
Stabilizers/Additives: Sometimes CO2 or inert gas under pressure to reduce explosion risk
Inhalation: Take exposed person into fresh air fast, keep airway clear, if trouble breathing, provide medical oxygen and call emergency services immediately
Skin Contact: Remove contaminated clothing, flush skin with water for at least 20 minutes, do not rub; cover burns loosely, get medical help fast
Eye Contact: Hold eyelids open and rinse eyes using water for at least 20 minutes, seek medical help
Ingestion: Do not induce vomiting; rinse mouth, keep person calm, contact medical professionals right away
Most Serious Effects: Shortness of breath, coughing, confusion, burns, cancer risk following long-term exposure
Special Notes: Trained responders only for rescue; oxygen and positive-pressure breathing equipment advised
Suitable Extinguishing Media: Dry chemical, carbon dioxide, water spray (only if safe), dry sand–avoid foam
Specific Hazards: Vapors form explosive mixtures with air; can ignite from static, heated surfaces, or sparks
Protective Equipment: Full flame-resistant gear, self-contained breathing apparatus; chemical-resistant gloves and boots
Advice for Firefighters: Evacuate area, cool tanks with water from distance, avoid inhaling fumes; keep upwind, be alert to very toxic gases like carbon monoxide/dioxide formed during burning, do not allow run-off from fire control to reach drains or water courses
Personal Precautions: Remove all ignition sources, ventilate immediate area, evacuate all unnecessary personnel; put on appropriate chemical respirator, gloves, and suit
Environmental Precautions: Prevent release into water, soil, storm drains; use dikes, absorbent materials for liquids
Cleanup Methods: For small leaks, ventilate and absorb with inert material such as clay or dry sand; for larger spills, contain vapor cloud with water fog but do not spray streaming water directly; collect residue for hazardous disposal
Special Instructions: Only trained hazardous material response teams should attempt spill cleanup; provide continuous gas monitoring to avoid explosion risks during all cleanup and ventilation
Safe Handling: Use spark-proof equipment and tools rated for flammable gases; ground all containers; avoid breathing vapors; never taste or directly touch product; work in chemical fume hood or externally vented system—never use in confined, unventilated spaces
Storage Conditions: Store in tightly closed containers, away from heat, direct sunlight, and incompatible chemicals (acids, alkalis, halogens, oxidizers); maintain proper ventilation; keep cylinders or drums upright, with secure caps and pressure relief devices
Storage Temperature: Below 30°C (86°F) preferred, avoid freezing conditions
Special Storage Points: Signage, access limits; only trained, authorized persons allowed; no smoking, welding, or open flames nearby
Exposure Limits: OSHA PEL: 1 ppm (1.8 mg/m3), ACGIH TLV: 1 ppm TWA, NIOSH REL: lowest feasible limit
Engineering Controls: Local exhaust ventilation, explosion-proof electrical systems, continuous gas monitoring
Personal Protective Equipment: Respirators with organic vapor cartridges for low-level exposures, positive pressure supplied-air respirators for higher levels or emergencies, chemical goggles, face shield, flame-resistant coveralls, butyl rubber gloves, chemical-resistant boots
Hygiene Measures: No eating, drinking, or smoking in work area; wash hands and face thoroughly after handling; emergency safety showers and eyewash stations in all work zones
Appearance: Colorless, flammable gas with sweet ether-like odor
Molecular Weight: 44.05 g/mol
Boiling Point: 10.4°C (50.7°F)
Melting Point: –111.3°C (–168.3°F)
Flash Point: –20°C (–4°F)
Explosion Limits in Air: Lower 3%, upper 100% (extreme hazard in all practical concentrations)
Vapor Density: 1.49 (air = 1)
Solubility: Miscible with most polar solvents, moderately soluble in water
Vapor Pressure: ~1,095 mm Hg at 20°C (high, disperses quickly)
Odor Threshold: 260 ppm (above safe exposure level)
Chemical Stability: Stable at room temperature under recommended storage conditions; heat, sunlight, or exposure to alkalis/acids can trigger violent reactions
Hazardous Reactions: Strongly reactive with oxidizers, acids, alkalis, water (slow hydrolysis), chlorinated compounds; explosion hazard in presence of silver, copper, mercury catalysts
Decomposition Products: Ethylene glycol, acetaldehyde, carbon monoxide/dioxide
Conditions to Avoid: Heat, sparks, open flames, direct sunlight, incompatible chemicals
Acute Toxicity: Inhalation can cause headache, nausea, dizziness, lung and nervous system injury; high concentrations lead to death
Chronic Toxicity: Long-term exposure increases risk of leukemia, brain cancer, breast cancer, and lymphoma; links to reproductive harm and birth defects
Irritation: Eye and skin burns resulting from contact; inhalation causes nose/throat irritation, coughing, and chest pain
Sensitization: Repeated exposure can result in allergic skin or lung reaction
Target Organs: Lungs, liver, kidneys, nervous system, blood
Environmental Fate: Highly volatile, disperses rapidly in air; moderate persistence in groundwater and soil
Bioaccumulation: Not expected to build up in organisms due to volatility and rapid degradation
Acute Environmental Toxicity: Toxic to aquatic organisms at high concentrations; vapor can cause indirect hazards in confined or poorly ventilated areas
Degradation: Breaks down slowly in water, reacts with atmospheric hydroxyl radicals within days
Waste Treatment: Controlled incineration or chemical neutralization in approved hazardous waste facilities; never pour down drains or dispose in regular trash
Disposal Containers: Use sealed, labeled drums or gas cylinders for capture; keep incompatible materials far apart during collection
Special Disposal Instructions: Only licensed professionals should handle and dispose of ethylene oxide waste, following both local and federal hazardous material rules
UN Number: 1040
Shipping Name: Ethylene Oxide
Hazard Class: 2.3 (Toxic gas), subsidiary risk 2.1 (Flammable gas)
Packing Group: I (highest hazard)
Labeling Requirements: Toxic, flammable gas signs; emergency information required on containers
Special Precautions for Transport: Keep cylinders upright and cool; secure tightly during transit; use leak-proof, explosion-proof vehicles and containers; all handlers must have protective gear and spill response tools
OSHA Standards: Listed as carcinogen, subject to strict exposure and reporting rules
EPA Status: Classified hazardous air pollutant; subject to strict emission and release reporting under Clean Air Act and CERCLA
DOT Shipping: Regulated as highly dangerous material; shipping paper and marking requirements; only licensed, trained hazmat carriers may transport
International Regulations: Listed under UN, IATA, and IMDG hazard schedules; subject to global transport, disposal, and use restrictions due to flammability and cancer risks
SARA Title III (EPCRA): Extremis hazardous substance, subject to planning, reporting, and emergency notification rules for all threshold quantities
