Chlorinate This

It is academic, because Theresa May and her Cabinet allies, for so in fact they are, have now made it highly improbable that we are ever going to leave the EU. But the United States has at least declared its hand on a trade deal if we did. 

While such deals with the United States, Canada, Australia and New Zealand are unobjectionable in principle, food safety and the National Health Service are both among the things that are absolutely non-negotiable.

Whether by the United Kingdom, outside the European Union. Or by the European Union, with the United Kingdom in it.