Hiroshi,
I second that.
Chemical safety is a variable thing.
Peanuts are safe, some people have an allergy to nuts though..... so not safe for all.
Safe/ non toxic/ etc clays/ paints could be likened to my above statement of peanuts. Safe for the vast majority, some people may have a sensitivity issue.
I commend all involved for striving to be open, offering supporting data, and remaining friendly.
No kicking, biting, scratching or name calling, everyone remained civil and adult.
It's what keeps the site good, and makes the mods job easier.
Plus, keeping the hobby safe(r) for us and our families is a good thing to be reminded of.
Cheers