Acetic acid is a chemical reagent for the production of chemical compounds. The largest single use of acetic acid is in the production of vinyl acetate monomer, closely followed by acetic anhydride and ester production. The volume of acetic acid used in vinegar is comparatively small.

• Medical: Acetic acid is used as part of cervical cancer screening in many areas in the developing world. The acid is applied to the cervix and if an area of white appears after about a minute the test is positive.
• Food: Vinegar is used directly as a condiment, and in the pickling of vegetables and other foods. Table vinegar tends to be more diluted (4% to 8% acetic acid), while commercial food pickling employs solutions that are more concentrated.
• Use as Solvent: As a polar protic solvent, acetic acid is frequently used for recrystallization to purify organic compounds. It is essential in the production of terephthalic acid (TPA), the raw material for polyethylene terephthalate (PET).

Acetic acid is produced industrially both synthetically and by bacterial fermentation. About 75% of acetic acid made for use in the chemical industry is made by the carbonylation of methanol. The biological route accounts for only about 10% of world production, but remains vital for food-grade vinegar production.

Global production has seen significant growth, increasing from 10.7 Mt/a in 2010 to approximately 17.88 Mt/a in 2023. Major global markets include the United States, Europe, and Japan, with recycling contributing an additional 1.5 Mt annually.

In this process, methanol and carbon monoxide react to produce acetic acid. The process involves iodomethane as an intermediate and requires a metal carbonyl catalyst.

Modern plants utilize the iridium-catalyzed Cativa process, which is recognized as a greener and more efficient alternative to the older Monsanto process.

Second-most-important manufacturing method involves the oxidation of acetaldehyde. Acetaldehyde can be derived from the hydration of acetylene or via the Wacker process from ethylene. Recent commercialization of single-stage conversion of ethylene to acetic acid uses a palladium metal catalyst supported on heteropoly acid.