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Name: Cyclopentene
Chemical Formula: C5H8
CAS Number: 142-29-0
Appearance: Clear, colorless liquid
Odor: Mild sweet smell reminiscent of gasoline
Boiling Point: Around 44 °C
Molecular Weight: 68.12 g/mol
Flammable Properties: Highly flammable liquid and vapor
Health Hazards: Causes skin irritation, may cause eye damage, inhalation can lead to respiratory irritation and drowsiness
Environmental Risks: Harmful to aquatic life, risk of long-term effects in the water system
GHS Classification: Flammable liquid (Category 2), Acute toxicity (Oral and Dermal), Skin irritation (Category 2), Eye irritation (Category 2A), Specific target organ toxicity (STOT-SE Category 3)
Hazard Symbols: Flame and exclamation mark pictograms under GHS
Cyclopentene (C5H8): Typically at concentrations above 95% in commercial product
Impurities: Trace amounts of other cycloalkenes or hydrocarbons depending on source, generally below 5%
Inhalation: Remove person to fresh air, keep comfortable, seek medical advice if symptoms persist
Skin Contact: Wash with plenty of soap and water, remove contaminated clothing, consult physician for persistent irritation
Eye Contact: Rinse cautiously with water for several minutes, remove contact lenses if present, continue rinsing, get medical attention if irritation develops
Ingestion: Rinse mouth, do not induce vomiting, seek medical attention quickly
Note: Symptoms might include headache, dizziness, or irritation. Quick action helps avoid complications.
Suitable Extinguishing Agents: Foam, dry chemical powder, carbon dioxide
Unsuitable Extinguishing Agents: Direct water jet can spread fire
Specific Hazards: Forms explosive mixtures with air, vapors heavier than air, risk of flashback
Precautions for Firefighters: Wear self-contained breathing apparatus and full protective gear, keep run-off out of drains
Special Procedures: Cool exposed containers with water spray to prevent bursting
Personal Precautions: Evacuate area, wear protective gloves and eyewear, ventilate area
Environmental Precautions: Avoid release to drains, soil, or waterways, contain run-off
Cleanup Methods: Use inert absorbent like sand or vermiculite, scoop into proper waste container, seal, and dispose according to local guidelines, ventilate and wash area after cleanup
Handling Practices: Use only in well-ventilated areas, avoid inhaling vapors, avoid contact with skin and eyes, keep away from ignition sources such as open flames, sparks, or hot surfaces
Storage Conditions: Store in tightly closed containers, in cool and well-ventilated place, keep away from oxidizers and acids, use only non-sparking tools for handling
Special Instructions: Ground and bond containers and equipment, keep proper records of storage and usage for safety audits
Occupational Limits: No established exposure limits for cyclopentene, but minimize exposure by following industrial hygiene practices
Protective Gear: Chemical splash goggles, gloves resistant to solvents, lab coat or coveralls, flame-retardant clothing in high-risk areas
Engineering Controls: Local exhaust ventilation, intrinsically safe electrical fittings in storage and use areas
Respiratory Protection: Use a respirator or mask if ventilation is insufficient or if vapor concentrations exceed recommended guidelines (like those for similar alkenes)
Appearance: Clear, colorless liquid
Odor: Mild, sweet, gasoline-like
Boiling Point: Approx. 44 °C
Melting Point: −135 °C
Flash Point: −34 °C (very low, makes fire risk high)
Density: Around 0.78 g/cm³
Solubility in Water: Slightly soluble
Vapor Pressure: High, can result in quick accumulation of vapors in enclosed spaces
Auto-Ignition Temperature: Around 380 °C
Chemical Stability: Stable at room temperature and standard conditions with proper containment
Reactivity: Readily reacts with strong oxidizing agents
Hazardous Decomposition Products: Carbon monoxide, carbon dioxide, irritating organic vapors if burned
Polymerization: Can occur under certain circumstances, risk of a runaway reaction if not controlled
Situations to Avoid: Heat, flames, sparks, contact with strong acids or oxidizers
Acute Effects: Short-term exposure causes respiratory irritation, dizziness, headache, skin and eye irritation
Routes of Exposure: Inhalation, skin contact, eye contact, accidental ingestion
Sensitization: No strong evidence for allergic sensitization from cyclopentene
Chronic Effects: No thorough research on long-term impacts in humans, but prolonged exposure might lead to effects similar to other light hydrocarbons
Animal Data: Some animal studies show neurological effects at high exposures
Aquatic Toxicity: Harmful to aquatic organisms, should not be discarded into water bodies
Mobility: Will volatilize quickly from surface soils and water
Persistence and Degradability: Will break down in air by reaction with hydroxyl radicals, not considered persistent
Bioaccumulation: Low to moderate potential, avoid chronic leakage into the environment
Product Disposal: Incinerate or chemically treat in compliance with local, state, and federal regulations; do not dump into drains or water systems
Container Disposal: Empty containers carry vapor residue; triple rinse and puncture before recycling or landfilling under regulatory rules
Precautions: Always ensure containers are fully emptied or rendered non-hazardous before disposal
UN Number: UN 1993 (for flammable liquids, n.o.s.—Cyclopentene included)
Transportation Hazard Class: Class 3: Flammable liquid
Packing Group: II (medium danger), watch for leaks and secure all storage during transit
Shipping Label: Flammable Liquid
Regulatory Advice: Comply with all local, national, and international rules for flammables during shipment; avoid stacking with incompatible materials, document all transfers
Occupational Safety: Cyclopentene falls under rules for hazardous chemicals in workplaces; safety training is essential for all users
Chemical Inventory Reporting: Listed on major international inventories, such as TSCA and EINECS, so reporting and tracking apply
SARA Title III (US): Requires reporting if spill reaches threshold limits due to flammability and aquatic concern
Waste Handling: Categorized as hazardous waste in many regions, must track handling, storage, and disposal as part of regulatory compliance
