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Chemical Name: 2-Methyl-3-Butyn-2-Ol
Synonyms: Methylbutynol, MBY
Molecular Formula: C5H8O
CAS Number: 115-19-5
Common Uses: Intermediate for pharmaceuticals, agrochemicals, dyestuffs, and fine chemicals
GHS Classification: Irritant to eyes, skin, and respiratory tract. Flammable liquid and vapor.
Hazard Statements: Causes serious eye irritation. May cause skin irritation. Harmful if swallowed or inhaled. Flammable liquid poses fire risk both during storage and use.
Pictograms: Flame, exclamation mark.
Other Issues: Potential for unsafe exposure during transfer, mixing, and disposal due to volatility.
Chemical Purity: Typically above 99% in laboratory and industrial grades.
Key Ingredient: 2-Methyl-3-Butyn-2-Ol. Any notable impurities often stem from synthesis remains but are rarely labeled unless concentration exceeds regulatory thresholds.
Related Compounds: Presence of water or residual alkynes in low amounts.
Inhalation: Remove exposed person to fresh air, support breathing as needed. Symptoms include coughing, headache, and dizziness.
Skin Contact: Remove contaminated clothing, flush affected skin with soap and water for several minutes. Persistent irritation calls for medical care.
Eye Contact: Rinse eyes for several minutes under gentle flow. Seek medical attention if redness, pain, or vision problems persist.
Ingestion: Rinse mouth thoroughly, never induce vomiting unless advised by health professionals. Rapid medical attention can reduce risk of complications.
Suitable Extinguishing Media: Alcohol-resistant foam, dry chemical powder, carbon dioxide. Water sprays cool surfaces but may not suppress vapors as effectively.
Specific Hazards: Vapors may form explosive mixtures with air. Containers exposed to fire can rupture violently.
Special Protective Equipment: Chemical-resistant suit and self-contained breathing apparatus.
Advice for Firefighters: Remain upwind, avoid inhaling combustion byproducts like carbon monoxide or other toxins.
Personal Precautions: Evacuate unnecessary personnel, ventilate area, wear suitable protective gear (gloves, goggles, mask).
Environmental Precautions: Prevent liquid from entering drains, sewers, or waterways. Contain spills with sand or inert material.
Cleanup Methods: Absorb with inert material, seal in chemical-safe containers. Wash contamination area after cleanup ensuring minimal contact with the product.
Handling: Transfer and use only in well-ventilated settings with explosion-proof equipment. Avoid direct skin and eye contact. Never smoke or use open flames nearby.
Storage: Store in cool, dry, tightly sealed containers away from heat and spark sources. Segregate from oxidizers, acids, and other incompatible chemicals. Good labeling and regular inspection guard against accidental mixing or spills.
Engineering Controls: Fume hoods, efficient ventilation, and explosion-protected setups limit vapor buildup.
Personal Protective Equipment: Nitrile or neoprene gloves, safety goggles, and solvent-proof clothing shield users from exposure. Respiratory protection matters in high vapor areas.
Hygiene Measures: Wash hands and exposed skin before breaks and after handling. Eating or drinking around chemicals increases risk unnecessarily.
Appearance: Colorless liquid
Odor: Mild, sweet, and slightly pungent
Boiling Point: About 102°C
Melting Point: Below room temperature
Flash Point: Approximately 29°C (closed cup)
Solubility: Miscible with water, alcohols, and common organic solvents.
Other Features: Volatile, strong enough to produce flammable vapors at typical room temperatures.
Stable At: Ambient temperature in closed containers, out of sunlight.
Conditions To Avoid: Avoid heat, flames, static discharge, and strong oxidizing or reducing agents.
Hazardous Reactions: Contact with strong acids produces heat and fumes. Decomposition releases toxic gases under fire or extreme heat.
Polymerization: Unlikely under normal storage but possible with catalyst presence.
Routes of Entry: Inhalation, dermal, ocular, ingestion
Acute Effects: Eye irritation, skin redness, respiratory discomfort, headache, and gastric distress in some cases.
Chronic Exposure: Repeated skin contact leads to dermatitis. Long-term high vapor exposure risks respiratory irritation or central nervous system symptoms.
LD50 (Oral, Rat): Approximately 1000 mg/kg based on published toxicology reports.
IARC/OSHA Classification: Not listed as a probable or known carcinogen.
Mobility: Considerable in soil and water owing to water solubility.
Aquatic Toxicity: Harmful to aquatic life at higher concentrations. Discharge into water bodies can disrupt local ecosystems.
Persistence and Degradability: Biodegradable in aerobic conditions but can accumulate locally if frequently released.
Bioaccumulation: Low likelihood given rapid breakdown and water solubility.
Waste Handling: Treat residues and contaminated items as hazardous waste. Use proper chemical waste disposal routes rather than landfill or sewer release.
Neutralization: Works best at licensed chemical facilities equipped to handle flammable, irritant liquids.
Container Cleanout: Empty containers remain hazardous until triple-rinsed and properly aired before recycling or disposal.
UN Number: UN 1992
Hazard Class: 3 (Flammable Liquid)
Packing Group: II
Proper Shipping Name: Flammable liquids, n.o.s. (contains 2-Methyl-3-Butyn-2-Ol)
Transport Precautions: Well-sealed, correctly labeled drums or containers. Temperature and spark control during transit. Rapid response to leaks avoids escalation.
OSHA: Listed as hazardous due to flammability and irritant traits.
TSCA: 2-Methyl-3-Butyn-2-Ol appears on the U.S. Toxic Substances Control Act inventory.
SARA Title III: Not classified as an extremely hazardous substance, but significant spills require notification in many states.
REACH: Registered for handling within the European Union with similar hazard statements.
Other Local Regulations: Site-specific rules might apply, especially where chemical storage limits or worker exposure controls are stricter than federal rules.
