γ-Butyrolactone (GBL) is a hygroscopic colorless, water-miscible liquid with a weak characteristic odor. It is the simplest 4-carbon lactone. It is mainly used as an intermediate in the production of other chemicals, e.g. methyl-2-pyrrolidone. In humans GBL acts as a prodrug for γ-hydroxybutyric acid (GHB), and it is used as a recreational CNS depressant with effects similar to barbiturates.


Melting Point−45 °C
Boiling Point204°C
Flash Point98 °C
Density1.12 g/mL at 25 °C

Uses and Applications



  • Cleaning
  • Cosmetics
  • Water Treatment

Synonyms: 1,2-butanolide I 1,4-Butanolide I 1,4-Lactone I 4-Butyrolactone

Chemical Formula: C4H6O2

CAS Number: 96-48-0