I don't know that this particular retardant is a big deal, but the rule really ought to be that the maker of every product must disclose to the public (not just actual buyers) (a) what they put into it, (b) where they got it, (c) how they assured that it was what they thought it was, (e) how they processed it, (e) exactly what analyses or characterizations they've ever done on the product or anything that went into it, and (f) the complete results of those.
Trade secrets not only shouldn't get any legal protection, but in many cases they should be illegal.