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Product Name: Methyl Tert-Butyl Ether
Chemical Formula: C5H12O
Synonyms: MTBE, tert-Butyl methyl ether
CAS Number: 1634-04-4
Recommended Use: Fuel additive
Supplier Information: Manufacturer's and distributor’s contact details listed on branded labels, including emergency telephone number for hazardous spills.
GHS Classification: Flammable liquid category 2, Acute toxicity (oral) category 4, Aspiration hazard category 2
Symbol: Flame, exclamation mark
Signal Word: Danger
Hazard Statements: Highly flammable liquid and vapor, may cause drowsiness or dizziness, harmful if swallowed, may cause respiratory irritation, harmful to aquatic life with long-lasting effects
Precautionary Statements: Keep away from heat, sparks, open flames, and hot surfaces; no smoking. Use only outdoors or in well-ventilated space. Avoid breathing vapors. Prevent release to the environment. If inhaled: move to fresh air and keep at rest.
Substance: Methyl Tert-Butyl Ether
Chemical Identity: C5H12O
Concentration: Over 99.5% by weight
Impurities: May include trace hydrocarbons and alcohols below regulatory significance limits
Inhalation: Remove exposed individual to fresh air. If trouble breathing, use supplemental oxygen and seek medical help
Skin Contact: Wash thoroughly with soap and water. Remove contaminated clothing. Immediate medical attention advised if irritation or persistent discomfort occurs.
Eye Contact: Rinse with large quantities of water for at least 15 minutes. Remove contact lenses if present and easy to do. Medical evaluation should follow if symptoms persist.
Ingestion: Do not induce vomiting. Rinse mouth and seek immediate medical help. Symptoms like nausea, headache, or disorientation require prompt doctor involvement.
Suitable Extinguishing Media: Alcohol-resistant foam, dry chemical, carbon dioxide, water fog
Unsuitable Media: Direct water jet due to spread of flammable liquid
Specific Hazards: Vapors can form explosive mixtures with air. Containers may rupture from pressure. Fire may produce toxic fumes of carbon monoxide and oxides of carbon.
Protective Equipment: Self-contained breathing apparatus and full protective gear needed for all personnel involved with extinguishing
Special Precautions: Cool exposed containers with water spray. Evacuate personnel from immediate hazard area.
Personal Precautions: Shut off leaks if without risk. Use protective gear—chemical splash goggles, gloves, flame-resistant clothing. Eliminate all sources of ignition from area.
Environmental Precautions: Prevent entry into drains, stormwater, or bodies of water. Report spills to relevant authorities as legally required.
Small Spills: Absorb with inert dry material (sand or earth), sweep up and transfer to suitable containers for disposal.
Large Spills: Dike area to contain further migration. Use emergency procedures to isolate hazard zone. Arrange safe disposal through a licensed waste contractor.
Handling: Wear splash-proof goggles, gloves, and antistatic garments. Ground and bond containers during transfer operations. Use only with adequate ventilation.
Storage: Store in tightly closed containers, away from direct sunlight and incompatible materials such as strong acids, oxidizers, and halogens. Keep in well-ventilated, dedicated flammable liquid storage area with proper containment measures.
Further Guidance: Avoid repeated or prolonged skin exposure. Do not smoke, eat, or drink in handling area. Use explosion-proof equipment.
Occupational Exposure Limits: OSHA PEL: 50 ppm (180 mg/m³), ACGIH TLV: 50 ppm
Engineering Controls: Use local exhaust ventilation and closed system operation for processes handling the liquid.
Personal Protection:
- Respiratory: NIOSH-approved organic vapor respirator if concentration exceeds limits
- Skin: Nitrile or neoprene gloves, flame-resistant clothing
- Eye: Chemical splash goggles and face shield in splash-risk environments
Hygiene: Wash hands before meals and after handling. Remove contaminated clothing; clean before reuse.
Physical State: Liquid
Color: Colorless
Odor: Ether-like, slightly sweet
Boiling Point: 55.2°C (131°F)
Melting Point: -109°C
Flash Point: -28°C (-18°F), closed cup
Vapor Pressure: 245 mmHg at 25°C
Solubility: Slightly soluble in water (4.8g/L at 25°C); miscible with most organic solvents
Density: 0.74 g/cm³ at 20°C
Vapor Density: 2.55 (air = 1)
Auto-Ignition Temperature: 285°C (545°F)
Explosive Limits: 1.1–8.6% (v/v in air)
Chemical Stability: Stable under ordinary conditions, but vapors may accumulate and ignite explosively above flash point.
Conditions to Avoid: Exposure to ignition sources, direct sunlight, and high temperatures
Materials to Avoid: Strong oxidizers, strong acids, alkali metals
Hazardous Decomposition: Forms carbon monoxide, carbon dioxide, and various aldehydes during combustion.
Polymerization: Not anticipated under normal storage and handling.
Acute Toxicity: Oral LD50 (rat): 3860 mg/kg. May cause headache, nausea, dizziness, and incoordination.
Chronic Exposure Risks: High vapor concentrations can affect the central nervous system. Prolonged exposure may lead to liver and kidney changes.
Skin Contact: Prolonged or repeated exposure can cause defatting, redness, and dryness.
Eye Contact: Direct splash can cause moderate transient irritation.
Inhalation: High concentrations irritate mucous membranes, cause narcosis, potential respiratory distress.
Carcinogenicity: Not classed as carcinogenic by IARC, NTP, or OSHA at regulated exposure levels. Animal studies have shown mixed evidence at high exposures.
Eco-toxicity: Harmful to aquatic organisms, may cause long-term effects; Daphnia EC50 (48hr): 491 mg/L. Toxic to some fish at elevated levels.
Mobility: High potential for groundwater contamination owing to significant water solubility and limited soil adsorption.
Persistence/Degradability: Degrades slowly in environment; not readily biodegradable under typical conditions.
Bioaccumulative Potential: Low bioconcentration in aquatic organisms has been observed.
Other Effects: Volatile organic compound, can contribute to air pollution in urban settings when improperly released.
Waste Management: Dispose of contents/containers by a licensed hazardous waste handler. Comply with local, state, and federal disposal regulations.
Incineration: Suitable for burning in chemical incinerators equipped with afterburner and scrubber to capture emissions.
Do Not: Discharge waste into sewer or surface waters. Do not reuse empty containers; triple rinse before discarding.
UN Number: UN2398
Proper Shipping Name: Methyl tert-butyl ether
Hazard Class: 3 (Flammable liquids)
Packing Group: II
Label: Flammable liquid, Class 3
Marine Pollutant: Not specifically listed, but environmental risk warrants careful transit
Special Transport Guidance: Ship in tightly sealed, suitable steel or aluminium containers. Comply with all applicable transportation regulations. Keep away from oxidizing agents and acids in bulk shipments.
TSCA: Listed in the U.S. Toxic Substances Control Act inventory
SARA Title III: Subject to reporting under Sections 311/312 (acute/chronic/fire hazard). Noted in Section 313 (toxic chemical release inventory)
Clean Air Act: Recognized as a hazardous air pollutant in part due to risk of ozone formation
OSHA Classification: Flammable liquid, regulated for worker safety
California Proposition 65: Not currently listed as a cancer or reproductive toxicant
International Inventories: Listed in Canada (DSL/NDSL), Europe (EINECS), Japan (ENCS), Australia (AICS), and numerous other country inventories
