Difluoroacetic acid (TFA), Difluoroethanoic Acid, '2,2-Difluoroethanoic acid', Perfluoroacetic acid, is the simplest stable perfluorinated carboxylic acid chemical compound, with the formula CF₃CO₂H. It is a strong carboxylic acid due to the influence of the electronegative trifluoromethyl group. TFA is almost 100,000-fold more acidic than acetic acid. TFA is widely used in organic chemistry.
TFA occurs naturally in sea water, but only in small concentrations (<200 ng/L). TFA is prepared industrially by the electrofluorination of acetyl chloride and acetic anhydride, followed by hydrolysis of the resulting trifluoroacetyl fluoride:
CH₃COCl+ 4 HF → CF₃COF + 3 H₂ + HCl
CF₃COF+ H₂O → CF₃COOH + HF
Where desired, this compound may be dried by addition of trifluoroacetic anhydride. An older route to TFA proceeds via the oxidation of 1,1,1-trifluoro-2,3,3-trichloropropene with potassium permanganate. The trifluorotrichloro-propene can be prepared by Swarts fluorination of hexachloropropene.

1. Store in a cool, dry place.
2. Keep container closed when not in use. Corrosives area.
3. Keep containers tightly closed.
4. Store in metal containers.