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Hydrocarbons

Cyclopentene

Also known as 1-Cyclopentene, 1-Cyclopentene #, Cyclopentene, 96%

CAS 142-29-0Formula C5H8Molar mass 68.12 g/molEC 205-532-9
GHS signal word: Danger. Pictograms: Flammable, Harmful or irritant, Serious health hazard 63 suppliers listed
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Cyclopentene chemical structure, C5H8, CAS 142-29-0
2D chemical structure

Key facts

What buyers check first

All properties
Physical form
Liquid
Melting point
-135 °C
Boiling point
44.4 °C
Density
0.774 - Less dense than water, will float
Flash point
-34.4 °C
HS code
290219
Category
Hydrocarbons
UN number
UN 2246
Illustrative photo, assorted laboratory chemical bottles and jars on a laboratory bench
Typical packagingIllustrative packaging image, not the actual product

What is Cyclopentene?

Plain description, key identifiers and synonyms

Cyclopentene is a cycloalkene that is cyclopentane having one endocyclic double bond.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
cyclopentene
CAS number
142-29-0 CAS number cross-checkedOther or deprecated CAS: 10016-46-3, 29300-20-7
EC number
205-532-9
Molecular formula
C5H8
UNII
ONM2CKV81Z
MDL number
MFCD00001394
InChIKey
LPIQUOYDBNQMRZ-UHFFFAOYSA-N
InChI
InChI=1S/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2
SMILES (canonical and isomeric)
C1CC=CC1

Synonyms

  • 1-Cyclopentene
  • 1-Cyclopentene #
  • Cyclopentene, 96%
  • Cyclopentene, p.a., 99.0%
  • Cyclopentene [UN2246] [Flammable liquid]
  • Cyclopentene Solution in Methanol, 5000ug/mL

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Physical form
Liquidexp.
Melting point
-135 °Cexp.
Boiling point
44.4 °Cexp.
Density
0.774 - Less dense than water, will floatexp.
Flash point
-34.4 °Cexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
68.12 g/molcalc.
Exact mass
68.0626 Dacalc.
LogP (octanol/water)
1.73calc.
Topological polar surface area
0 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
0calc.
Rotatable bonds
0calc.
Heavy atoms
5calc.
Rings
1calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.6calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, C1=CCCC1

C1=CCCC1

1 ring, 5 atoms. This chemical is the scaffold itself.

1,868 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS02: Flammable
Flammable
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H225Highly flammable liquid and vapour.
  • H302 + H312Harmful if swallowed. Harmful in contact with skin.
  • H302Harmful if swallowed.
  • H304May be fatal if swallowed and enters airways.
  • H312Harmful in contact with skin.
  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
  • H412Harmful to aquatic life with long lasting effects.
Precautionary statements (32)
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P233Keep container tightly closed.
  • P240Ground and bond container and receiving equipment.
  • P241Use explosion-proof electrical, ventilating and lighting equipment.
  • P242Use non-sparking tools.
  • P243Take action to prevent static discharges.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P273Avoid release to the environment.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P316If swallowed: Get emergency medical help immediately.
  • P301 + P317If swallowed: Get medical help.
  • P302 + P352If on skin: Wash with plenty of water.
  • P303 + P361 + P353If on skin (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P317Get medical help.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P331Do not induce vomiting.
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P370 + P378In case of fire: Use appropriate media to extinguish.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P403 + P235Store in a well-ventilated place. Keep cool.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 2246
Transport hazard class
3
Packing group
II

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Cyclopentene suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 63 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

63 suppliers in 16 countries

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Cyclopentene price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Industrial uses: Other, Intermediate.

Consumer uses: Other, Intermediate.

Regulatory status

Inventories, regulations and trade controls that list this substance

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Cyclopentene is traded under.

HS 2902.19Indicative HS code

Cyclanes, cyclenes and cycloterpenes, other

World exports in 2024
$979M
+24.3% vs 2023, imports $1B
2019 to 2024
Top exporters
  1. China23.4%
  2. United States20.6%
  3. Germany13.6%
Top importers
  1. India * partner reported9.9%
  2. United States9.8%
  3. South Korea9.5%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Cyclopentene is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Cyclopentene, based on the data on this page

What is Cyclopentene?

Cyclopentene is a cycloalkene that is cyclopentane having one endocyclic double bond.

What is the CAS number of Cyclopentene?

The CAS registry number of Cyclopentene is 142-29-0. Other or deprecated CAS numbers: 10016-46-3, 29300-20-7.

What is the molecular formula and weight of Cyclopentene?

The molecular formula of Cyclopentene is C5H8 and its molar mass is 68.12 g/mol.

What is Cyclopentene used for?

Industrial uses: Other, Intermediate. Consumer uses: Other, Intermediate.

Is Cyclopentene hazardous?

Cyclopentene carries the GHS signal word "Danger". Main hazards: highly flammable liquid and vapour, harmful if swallowed. harmful in contact with skin, harmful if swallowed. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Cyclopentene?

Cyclopentene is usually classified under HS code 290219 (Cyclanes, cyclenes and cycloterpenes, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Cyclopentene?

CompoundList lists 63 suppliers of Cyclopentene in United States, China, Germany, Spain and 12 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Cyclopentene in India?

1 supplier in India list Cyclopentene on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Cyclopentene?

Suppliers quote Cyclopentene on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Cyclopentene

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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