Melting point :78-80 °C (lit.)
Boiling point :200-203°C
Density :0,9641 g/cm³
refractive index :1.3918 (estimate)
Flash point :200-203°C
storage temp. :Sealed in dry,2-8°C
solubility :water: soluble50mg/mL, clear to very slightly hazy, colorless to very faintly yellow
form :Powder
pka :2.62(at 25℃)
color :White to yellow
Water Solubility :Soluble in water. Slightly soluble in methanol and chloroform.
BRN :1740205
InChI :1S/C4H4O2/c1-2-3-4(5)6/h1H3,(H,5,6)
InChIKey :LUEHNHVFDCZTGL-UHFFFAOYSA-N
SMILES :CC#CC(O)=O
CAS DataBase Reference :590-93-2(CAS DataBase Reference)
NIST Chemistry Reference :2-Butynoic acid(590-93-2)
EPA Substance Registry System :2-Butynoic acid (590-93-2)

Symbol(GHS):
Signal word:	Danger
Hazard statements:	Code Hazard statements Hazard class Category Signal word Pictogram P-Codes H314 Causes severe skin burns and eye damage Skin corrosion/irritation Category 1A, B, C Danger P260,P264, P280, P301+P330+ P331,P303+P361+P353, P363, P304+P340,P310, P321, P305+ P351+P338, P405,P501
Precautionary statements:	P260 Do not breathe dust/fume/gas/mist/vapours/spray. P280 Wear protective gloves/protective clothing/eye protection/face protection. P303+P361+P353 IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing. P363 Wash contaminated clothing before reuse.