I've been working with human-grade gear for over a decade, both US and overseas brands, and I've been doing conversions for over a decade as well. Trust me, BA is the main solvent as well as the sterilizing agent, and BB is not used by most HG gear. Trust me, I've seen the formulas we use in compounding pharmacies to MAKE HG gear. But believe whatever you want, I'll just keep using my "old-school" incorrect and painless gear. You can have painful prop and blame it on the "ester"