PGB (peppys group buy) has started random sterility testing for their products from XYX (anonymous vendor they use) and I haven't seen a fail yet, although i suppose it's worth noting that the PGB organizers are sending in these test vials and posting the results. however, they haven't given me any reason not to trust them.
historically there were passes across various vendors that were tested, the pass rate was higher than the fail rate, which is what made this tirz disaster so bizarre with most vendors failing. my general threshold is multiple failed tests, outside of this tirz situation, but with Amo the fact that they're not even testing internally and don't seem to want to make it right once their products failed, does not sit well with me.