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Chemical name: 1,3,5,7-Cyclooctatetraene
Synonyms: COT, Cycloocta-1,3,5,7-tetraene
Molecular formula: C8H8
CAS Number: 629-20-9
Appearance: Clear to pale yellow liquid
Odor: Aromatic, oily
Molecular weight: 104.15 g/mol
GHS classification: Flammable liquid (Category 2), Acute toxicity – oral, skin contact, eye irritation
Hazard statements: Highly flammable liquid and vapor, causes skin and eye irritation, harmful if swallowed or inhaled, may cause respiratory irritation
Pictograms: Flame, exclamation mark
Routes of exposure: Skin, eyes, inhalation, ingestion
Specific hazards: Vapors form explosive mixtures with air at room temperature, very low flash point increases risk during handling, direct contact may trigger allergic skin reactions or eye burns
Chemical identity: 1,3,5,7-Cyclooctatetraene
Concentration: Pure substance
Impurities: Trace residual polycyclic aromatics; information from suppliers usually specifies high-purity material for laboratory and industry uses
Inhalation: If a person feels dizzy or short of breath, move them into fresh air, loosen tight clothing, support breathing if needed
Skin contact: Wash affected skin immediately with soap and plenty of water, remove contaminated clothing
Eye contact: Flush eyes with water for at least 15 minutes while keeping eyelids apart, do not attempt to neutralize, seek medical help
Ingestion: Do not induce vomiting, rinse mouth with water, seek medical attention urgently, monitor for nausea or drowsiness
Suitable extinguishing media: Use dry chemical powder, CO2, or alcohol-resistant foam
Unsuitable media: Water streams may spread burning liquid
Fire hazards: Vapors heavier than air, may travel to distant ignition sources
Decomposition products: Burning generates carbon monoxide and toxic fumes
Protective action: Firefighters should wear full protective equipment and self-contained breathing apparatus, avoid inhaling combustion gases, cool exposed containers with water spray
Evacuation: Remove unnecessary personnel, ventilate affected area
Spill response: Absorb small spills with inert material like sand or activated charcoal, collect in containers for proper disposal
Containment: Prevent entry into drains or waterways, isolate area
Personal precautions: Gloves, goggles, chemical-resistant apron, face protection recommended in any clean-up
Handling: Work in ventilated areas, avoid breathing vapors, keep away from ignition sources, do not eat or drink around material
Storage: Store tightly sealed in a cool, dry, well-ventilated place away from heat, open flame, and strong oxidizing agents
Incompatibilities: Oxidizers, acids, alkali metals, sources of static discharge
Other safety notes: Use only non-sparking tools, ground and bond containers during transfer
Engineering controls: Local exhaust ventilation, explosion-proof equipment, fume hoods
Personal protective equipment: Gloves made from butyl or nitrile rubber, splash goggles, lab coat or flame-resistant clothing
Respiratory protection: Organic vapor respirator if ventilation proves inadequate
Hygiene measures: Wash hands thoroughly after handling, avoid contact with skin, remove any contaminated clothing, ensure eyewash stations are nearby
State: Liquid at room temperature
Color: Colorless to pale yellow
Odor: Aromatic with a somewhat sharp note
Melting point: -4.5 °C
Boiling point: 142 °C
Flash point: 14 °C (closed cup)
Ignition temperature: 395 °C
Vapor pressure: About 4.7 mmHg at 20 °C
Solubility: Insoluble in water, mixes well with most organic solvents
Density: 0.980 g/cm3 at 20 °C
Chemical stability: Stable at ambient temperature when stored in sealed containers away from air and light
Reactive conditions: Unstable in presence of strong acids, bases, oxidizing agents, and under intense light or heat
Hazardous decomposition: Carbon oxides generated during thermal decomposition or burning
Polymerization: May undergo polymerization under extreme conditions, rarely encountered in lab-scale storage
Likely routes of exposure: Inhalation, skin, eyes, oral
Acute effects: Headache, dizziness, nausea, skin irritation, allergic reactions on repeated skin contact
Chronic effects: Long exposure could cause damage to the nervous system, liver, or kidney, data limited due to the compound’s lower use outside research
LD50 (oral, rat): 695 mg/kg
Irritation: Contact with skin or eyes triggers redness, pain, possible swelling
Carcinogenic status: No classification as carcinogen, mutagenicity tests show uncertain results
Environmental impact: Harmful to aquatic life in concentrated spills, slowly biodegradable
Persistence: Breakdown in the environment through gradual oxidation and reaction with sunlight
Bioaccumulation: Potential exists due to limited water solubility and moderate vapor pressure, organisms exposed in contaminated sites may absorb compound in fatty tissues
Aquatic toxicity: Low solubility in water reduces direct exposure, but toxic in sufficient concentrations
Waste disposal: Consign unused or waste product to licensed chemical disposal facilities
Contaminated packaging: Triple rinse, puncture, and handle as hazardous waste
Do not pour down drains or into the environment, collection for incineration or similar high-temperature methods meets most regulations
Local regulations: Laboratories and businesses should consult country-specific hazardous waste guidelines, avoid landfill disposal where prohibited
UN Number: 2381
Shipping name: Cyclooctatetraene
Hazard class: 3 (Flammable liquid)
Packing group: II
Environmental hazards: Not regulated as a marine pollutant
Special precautions: Transport in robust, leak-resistant containers, avoid heat and direct sunlight in transit, label clearly with flammable liquid warnings
OSHA status: Covered under general chemical hygiene requirements in laboratory settings
EU regulations: Classified as hazardous by Regulation (EC) No 1272/2008 (CLP), includes pictograms for flammability, health hazard
TSCA: Listed in the U.S. Toxic Substances Control Act inventory
REACH: Pre-registered in Europe, subject to annual tonnage band restrictions for industrial users
Other regional constraints: Countries have their own limits for occupational exposure and transportation, always check local environmental safety codes
