Sorry to hear you´ve been ill.... I´m hoping you´ll be better really soon, especially after those incredible results you´ve been having and inspiring us to keep going in spite of the stony obstacles!
Pl excuse me, I cannot answer your question about the ES. If no one on this forum comes up with a good answer, may I suggest you take your question to the Ask Moreless Forum? Some years ago I bought a bag of ES that said USP as well on it and could´nt figure that one out. Moreless said (in my words!)that the USP was a USPharma grade "certifying" it had been cleaned and was OK to use. Apparently some ES can be contaminated. What a relief to know it was OK!
Here´s wishing you good health!