Propadiene

Propadiene
Names
	Preferred IUPAC name Propadiene
	Other names Allene; Propadiene
Identifiers
CAS Number	463-49-0 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1730774
ChEBI	CHEBI:37601 ;
ChEMBL	ChEMBL116960 ;
ChemSpider	9642 ;
ECHA InfoCard	100.006.670
EC Number	207-335-3;
Gmelin Reference	860
MeSH	Propadiene
PubChem CID	10037;
UNII	4AV0LZ8QKB ;
UN number	2200
CompTox Dashboard (EPA)	DTXSID1029178 ;
	InChI InChI=1S/C3H4/c1-3-2/h1-2H2 Key: IYABWNGZIDDRAK-UHFFFAOYSA-N ;
	SMILES C=C=C;
Properties
Chemical formula	C3H4
Molar mass	40.065 g·mol−1
Appearance	Colorless gas
Melting point	−136 °C (−213 °F; 137 K)
Boiling point	−34 °C (−29 °F; 239 K)
log P	1.45
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H220
Precautionary statements	P210, P377, P381, P410+P403
NFPA 704 (fire diamond)	0 4 3
Explosive limits	13%
Safety data sheet (SDS)	External MSDS
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Propadiene (/proʊpəˈdaɪiːn/) or allene (/ˈæliːn/) is the organic compound with the formula H₂C=C=CH₂. It is the simplest allene, i.e. a compound with two adjacent carbon double bonds. As a constituent of MAPP gas, it has been used as a fuel for specialized welding.