One thing Rees Moog and his crew want from Brexit is a lightening of the regulations around chemicals, something much desired, one has to suppose by a number of American firms whose products are produced in the laxer environment of the USA. Here is a nice article about how things mmay change in terms of consumer protection if we do a trade deal with the USA.

https://www.theguardian.com/commentisfree/2019/jan/08/carcinogens-cosmetics-brexit-britain-eu-makeup

Key points are not just the loss of the precautionary principle, but also the loss of informed choice as a result of no requirements for transparent labelling.