If is says internal then it'll be fine.
Telman and I aren't from the USA so perhaps they label and grade things differently in our countries??
If you can talk to a chemist/phamacist where you buy your ES perhaps you could just double check that there isn't a better grade you could use?? But, I feel almost certain if the one you're using says its for internal use then it's morst likely the same stuff as our better grade stuff anyway.
HTH
Anne (counting down - 2 days until liver flush!)