I actually had already read that information before, but I don't believe it. Because, the grapefruit seed extract I am using is 60% Grapefruit-Seed-Extract and the other 40% is just vegetable glycerine. Therefore, the Grapefruit-Seed-Extract has to be what is killing the bacteria. Anyway, all I know is, it is working for me. Also, I forgot to mention earlier, Grapefruit-Seed-Extract is supposed to be a great breath freshener as well.