Ivermectin is actually used orally in humans as a anti parasitic drug for roundworms. So other than killing our worms,I don't see a grave danger in that one. I understand you take every precaution with your compost sources and have your soil mixes tested. I do not have mine tested and I'd guess most personal use growers do not. I have a lot of respect for you and you have taught me a great deal. But, it won't change the fact I don't trust the FDA or EPA. For small personal use grows I would always suggest sourcing composting material from our own property if one can. Whether it's grass,leaves or dynamic accumulators. We have much more control knowing what has or hasn't been contaminated.