TCA peels are self neutralising.
The answer is none. I do not endorse high strength peels at home. TCA can result in scarring, if one does it incorrectly ( as can AHA peels).
The peel is self neutralising. You do not need to wash it off. Video explains.
Dr Davin Lim
Laser and aesthetic dermatologist
TCA Burn -- PLEASE SEE BOARD CERTIFIED MD
Please see a cosmetic dermatologist for treatment and evaluation. I suggest never doing a TCA peel at home. Best, Dr. Emer