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Chemical Name: 2-Methyl-3-butyn-2-ol
Common Synonyms: MBY alcohol, Pentynol
Chemical Formula: C5H8O
CAS Number: 115-19-5
Physical Appearance: Clear, colorless to pale yellow liquid
Odor: Strong, unpleasant, sharp
Uses: Widely found as an intermediate in organic synthesis, a solvent in coatings, and a component during synthesis of pharmaceutical and agricultural chemicals.
Hazard Classifications: Flammable liquid, Health hazard
Signal Word: Danger
Hazard Statements: Flammable liquid and vapor, May cause eye irritation, Prolonged or repeated skin exposure can trigger dryness or cracking, Vapors may cause irritation to respiratory tract
Pictograms: Flame, Exclamation mark
Precautionary Statements: Keep away from sparks, open flames and hot surfaces; Take precautionary measures against static discharge; Wear protective gloves and eye protection; Work only in well-ventilated areas; Avoid inhaling vapors and direct contact with skin and eyes
Component: 2-Methyl-3-butyn-2-ol
Concentration: Over 98% purity
Impurities: Trace hydrocarbons, minor polymerizable byproducts possible with extended storage
Hazard Components: Main health and physical hazards result from the high content of the primary compound, so impurity contribution is considered minor.
Inhalation: Bring affected persons to fresh air promptly. If breathing feels shallow or irregular, provide oxygen by trained personnel. Seek medical attention if symptoms persist.
Skin Contact: Wash areas thoroughly with water and mild soap. Remove contaminated clothing or accessories, launder thoroughly before reuse. Persistent irritation signals a need for professional evaluation.
Eye Contact: Rinse eyes immediately with running water, keeping eyelids open. Continue rinsing for several minutes. Remove contact lenses if present and easy to do. Medical assessment follows if symptoms do not improve.
Ingestion: Rinse mouth gently with water. Do not induce vomiting. Small oral exposures can trigger irritation, so monitor closely. Rapid professional evaluation is needed for significant or symptomatic ingestion.
Suitable Extinguishing Media: Alcohol-resistant foam, dry chemical powder, carbon dioxide, water spray for larger fires
Unsuitable Media: Direct stream of water against surface can spread fire
Specific Hazards: Vapors can form explosive mixtures with air, spread along surfaces to distant ignition sources. Storage containers exposed to fire may rupture violently.
Special Protective Actions: Firefighters use full protective gear including self-contained breathing apparatus; evacuate area and keep unauthorized personnel out of range; cool containers with water spray to prevent rupture
Personal Precautions: Eliminate all sources of ignition. Ensure proper ventilation for safe dispersal of vapors. Respiratory protection and chemical-resistant gloves increase personal safety.
Containment: Stop source of leak if possible without personal risk. Prevent entry into drains, soil, or waterways.
Cleanup Methods: Absorb spillage with non-combustible absorbents, such as sand or inert clay. Place absorbed material in suitable, labeled, fireproof containers. Ventilate area after cleanup.
Environmental Caution: Runoff or release to the environment presents a hazard to aquatic systems. Report significant releases to local authorities if required by law.
Handling: Handle only in well-ventilated locations to prevent vapor buildup. Use non-sparking tools and explosion-proof equipment. Avoid inhalation of vapors and repeated skin contact. Carefully ground and bond all containers to dissipate static charges that could ignite vapors.
Storage: Store in tightly closed, clearly labeled containers away from direct sunlight, sources of ignition, oxidizing materials, or acids. Recommended to keep at temperatures below ambient and in areas designated for flammable liquids.
Incompatibilities: Strong oxidizers, strong acids, halogens. These can produce hazardous reactions or degrade the integrity of containers.
Engineering Controls: Use mechanical ventilation, preferably local exhaust, to keep airborne concentrations well below recommended thresholds.
Eye Protection: Chemical splash goggles; face shields offer added protection for high-risk tasks.
Skin Protection: Chemical-resistant gloves made from nitrile or neoprene; long-sleeve clothing to reduce skin exposure.
Respiratory Protection: Use NIOSH-approved organic vapor respirators where ventilation proves inadequate.
Work Practices: Remove and wash contaminated clothing before reuse. Do not eat, drink, or smoke during chemical use.
Appearance: Colorless to pale yellow liquid
Boiling Point: Approximately 102 – 104°C
Melting Point: Near -12°C
Flash Point: Roughly 32°C (closed cup)
Vapor Pressure: Moderate, increases with temperature
Solubility: Miscible with water, alcohols, and organic solvents
Density: Around 0.92 g/cm³
Odor Threshold: Distinct, pungent smell detectable at low concentrations
Chemical Stability: Stable under standard conditions if kept dry and sealed
Hazardous Reactions: Polymerization unlikely unless subjected to strong acid catalysts
Incompatible Materials: Strong oxidizers, mineral acids, halogens—risk of violent reaction or spontaneous ignition if mixed
Decomposition Products: Burning releases carbon monoxide, carbon dioxide, and potentially toxic fumes. Overheating or improper storage may create corrosive vapors.
Acute Exposure: Inhalation brings headache, dizziness, throat irritation; contact with liquid irritates dermal tissue and eyes
Chronic Exposure: Prolonged or repeated skin exposure can result in dermatitis. Inhalation of high concentrations causes central nervous system depression.
Sensitization: Skin sensitization not commonly reported, though individual allergic reactions may occur
Mutagenicity and Carcinogenicity: Animal study data regarding DNA effects or cancer risk remains limited; the safety margin rests on industrial hygiene
LD50 (oral, rat): Documented near 2000 mg/kg, highlights moderate systemic toxicity
Aquatic Toxicity: Moderately toxic to aquatic organisms at high concentrations, presenting a risk in the event of large spills
Persistence and Degradability: Expected to break down in soil and water over short periods owing to oxygen and microorganism action
Bioaccumulation: Unlikely due to rapid metabolism and water solubility
Environmental Mobility: Migration through soil or into water courses possible if released in bulk, especially since the liquid dissolves in both water and organic phases
Disposal Methods: Small quantities can be incinerated by licensed waste handlers. Dilution and discharge into wastewater not advisable given flammable content and aquatic toxicity. Follow local regulations, and never release significant amounts into sewage or surface waters. Empty containers must be thoroughly drained, rinsed, and disposed of as hazardous waste owing to flammable residue.
UN Number: 1993 (Flammable liquid, not otherwise specified)
Proper Shipping Name: Flammable Liquid, N.O.S. (contains 2-Methyl-3-butyn-2-ol)
Hazard Class: 3 (Flammable liquids)
Packing Group: II or III, depending on transportation mode and concentration
Environmental Hazards: No marine pollutant designation, but always report large transport spills to relevant authorities
Special Precautions: Segregate from oxidizers and acids. Inspect containers before loading and unload with care to prevent puncture or spillage.
Workplace Limits: No established OSHA or ACGIH Threshold Limit Value; advisory indication recommends minimizing inhalation and skin contact
Safety Data Reporting: Subject to chemical inventory reporting in many jurisdictions
Label Requirements: Flammable liquid warning, precautionary handling, and first aid advice according to GHS criteria
Restrictions: Not classified as a controlled substance but regulated under hazardous chemicals acts owing to ignition and health threat
