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Olefins and dienes

Allene

Also known as 1,2-Propadiene, Propadiene, Dimethylenemethane

CAS 463-49-0Formula C3H4Molar mass 40.07 g/molEC 207-335-3
GHS signal word: Danger. Pictograms: Flammable, Gas under pressure 38 suppliers listed
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Allene chemical structure, C3H4, CAS 463-49-0
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Gas
Melting point
-136 °C
Boiling point
-34.5 °C
Density
1.787
Solubility
INSOL IN WATER, SOL IN BENZENE, PETROLEUM ETHER
HS code
290129
Category
Olefins and dienes
UN number
UN 2200
Illustrative photo, a gas cylinder on a trolley on a laboratory bench
Typical packagingIllustrative packaging image, not the actual product

What is Allene?

Plain description, key identifiers and synonyms

Allene is a member of allenes.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
propa-1,2-diene
CAS number
463-49-0 CAS number cross-checkedOther or deprecated CAS: 12075-35-3, 60731-10-4
EC number
207-335-3
Molecular formula
C3H4
UNII
4AV0LZ8QKB
MDL number
MFCD00008566
InChIKey
IYABWNGZIDDRAK-UHFFFAOYSA-N
InChI
InChI=1S/C3H4/c1-3-2/h1-2H2
SMILES (canonical and isomeric)
C=C=C

Synonyms

  • 1,2-Propadiene
  • Propadiene
  • Dimethylenemethane
  • Sym-allylene
  • Propa-1,2-diene
  • Propadiene-d4
  • CH2=C=CH2
  • Propadiene, inhibited
  • Allene, >=95%
  • UN 2200 (Salt/Mix)
  • 1,2-Propadiene-1,3-diylidene
  • Propadiene, inhibited [UN2200] [Flammable gas]
  • Allene (ca. 3.5% in Toluene, ca. 0.7 mol/L)
  • Allene (ca. 2% in Tetrahydrofuran, ca. 0.4 mol/L)
  • Allene (ca. 2% in N,N-Dimethylformamide, ca. 0.4 mol/L)

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

Appearance
Gasexp.
Melting point
-136 °Cexp.
Boiling point
-34.5 °Cexp.
Density
1.787exp.
Solubility
INSOL IN WATER, SOL IN BENZENE, PETROLEUM ETHERexp.
Vapour pressure
5990 [mm Hg] @20 °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
40.07 g/molcalc.
Exact mass
40.0313 Dacalc.
LogP (octanol/water)
0.96calc.
Topological polar surface area
0 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
0calc.
Rotatable bonds
0calc.
Heavy atoms
3calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS02: Flammable
Flammable
GHS04: Gas under pressure
Gas under pressure

Hazard statements

  • H220Extremely flammable gas.
  • H280Contains gas under pressure, may explode if heated.
Precautionary statements (8)
  • P203Obtain, read and follow all safety instructions before use.
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P222Do not allow contact with air.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P377Leaking gas fire: do not extinguish, unless leak can be stopped safely.
  • P381In case of leakage, eliminate all ignition sources.
  • P403Store in a well-ventilated place.
  • P410 + P403Protect from sunlight. Store in a well-ventilated place.
UN number
UN 2200
Transport hazard class
2.1

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

Allene suppliers

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

All 38 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

38 suppliers in 9 countries

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Allene price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Chain-transfer reagent in prodn of polybutadiene, fuel gas for metal-working industry (mixt with propyne), monomer for allene polymers (possible use).

Chemical intermediate in prodn of its isomer, propyne, methylenenorbornene, in hydroboration reactions (possible use).

Industrial uses: Intermediate, Other.

Consumer uses: Intermediate.

How it is made

Pyrolysis of propylene, isobutylene or a naphtha/gas oil mixt followed by sepn, eg, by naphtha adsorption, dehydrohalogenation of propylene dibromide with sodium hydroxide followedby sepn, cracking of t-butyl alcohol with steam as a diluent followed by sepn

A) action of zinc dust on 2,3-dichloropropene, b) pyrolysis of isobutylene, c) electrolysis of potassium itaconate.

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 Allene is traded under.

HS 2901.29Indicative HS code

Unsaturated, other

World exports in 2024
$2.65B
−3.2% vs 2023, imports $2.57B
2019 to 2024
Top exporters
  1. United States43.9%
  2. South Africa15.3%
  3. Qatar * partner reported9.0%
Top importers
  1. Singapore10.9%
  2. United States10.1%
  3. South Korea8.7%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

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

What is Allene?

Allene is a member of allenes.

What is the CAS number of Allene?

The CAS registry number of Allene is 463-49-0. Other or deprecated CAS numbers: 12075-35-3, 60731-10-4.

What is the molecular formula and weight of Allene?

The molecular formula of Allene is C3H4 and its molar mass is 40.07 g/mol.

What is Allene used for?

Chain-transfer reagent in prodn of polybutadiene, fuel gas for metal-working industry (mixt with propyne), monomer for allene polymers (possible use). Chemical intermediate in prodn of its isomer, propyne, methylenenorbornene, in hydroboration reactions (possible use). Industrial uses: Intermediate, Other.

Is Allene hazardous?

Allene carries the GHS signal word "Danger". Main hazards: extremely flammable gas, contains gas under pressure, may explode if heated. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Allene?

Allene is usually classified under HS code 290129 (Unsaturated, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Allene?

CompoundList lists 38 suppliers of Allene in United States, China, India, Germany and 5 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Allene in India?

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

What is the price of Allene?

Suppliers quote Allene 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 Allene

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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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