Please remeber, this is a competitive sport. Our performances are relative to each other. If we all race without certain chemicals then that is fair no matter what. In real motorsports, there have been many drastic rule changes, teams grumble; but racing continues.
I believe this issue has to start at t he top level of international competitions. If the World Championships, Reedys and ITCs were were to bann traction compounds and impound tires like radios, then it would work its way to the local level, where racers want to compete like the "big dogs". My local club runs races with IFMAR qualifying.
There are hundreds of thousands of chemicals in industry and as stated only a very few are tested and regulated. I have worked in Industrial Safety and Health for nearly twenty years. More often than I would like to remember a chemical has been regulated and replaced by a more toxic non-reguluated chemical.
While many of us are old enough to look out for ourselves, some like myself have children, who we want to share our hobby with and do not want to harm.
This is not an easy subject, but if we consider the health of others and remember we are still competing with each other no matter how the rules change.