from a reputable company @shallalah don't purchase from ebay or the like. Purchase from a company that will be there if you should have a question or concern. Purchasing acids from just anyone is asking for trouble, you never know how they've mixed it and what they have mixed it with, way too risky!! MUAC is one I recommend. Skin Obessions is another one to check out.
Be sure to check out our Chemical Peel forum, I have lots of info posted there on all sorts of peels, including TCA.