The detection of acetic acid (CH₃COOH) was reported in 1997 by Mehringer et al. toward the high mass star-forming region Sgr B2 (LMH) using the BIMA and OVRO arrays. Subsequent observations by Remijan et al. reported its presence in the hot cores Sgr B2(N) and W51.

Acetic acid is the basic ingredient of vinegar, a strong organic acid that is potentially dangerous when consumed in excess. It is the next carboxylic acid in the alkane series after formic acid, which is also an observed astromolecule.