AMERICA has confirmed that it would be prepared to start negotiations next year on a post-Brexit trade deal with Britain. No deal can be signed at once. For that, Britain will have to leave the EU customs union, and this cannot happen before 2021. But that does not stop the two countries from laying the groundwork for a future deal. America’s trade envoy, Robert Lighthizer, has called for an ambitious agreement. Agreeing to a deal will be important politically, to show that post-Brexit hopes for a “global Britain” are more than bluster.

Yet many Britons already worry about what this may mean. They fear that a Britain adrift from the EU will be in a weak negotiating position and obliged to make nasty compromises. These include opening up the NHS to foreign competition, and cutting consumer and environmental regulations. A particular bone of contention concerns chlorinated chicken. In America, after birds are slaughtered, their carcasses are washed with chemicals to manage pathogens such as salmonella and E. coli—a process known as “pathogen reduction treatment” (PRT). American exports of PRT-treated chicken have been rejected by the EU since 1997, and the issue remains a sore spot.

As part of any trade deal between America and Britain it seems highly likely that Britain will be required to accept PRT-treated birds. The EU argues that antimicrobial treatments compensate for poor hygiene in parts of the production process. It also says that rinses are used as an easy fix to try to clean up unclean meat. America says this attitude is unscientific and actually a form of protectionism, designed to shield poultry producers in the EU from imports of cheaper American chickens. It is also the case that American regulators, who have approved a number of different kinds of antimicrobial rinse for use in poultry processing, have deemed PRT safe, and that European scientists do not seem to think there is much to worry about.

Americans eat about 150m chickens each week that have been treated with PRTs, and they have come to little harm. Britons worried about these birds should consider that small amounts of disinfection byproducts are already ingested. According to the pro-trade Adam Smith Institute, chlorinated poultry would make up 0.3% to 1% of the disinfection byproducts consumed in the typical daily diet. (Drinking water makes up 99%.) American chickens would also be far cheaper, which would greatly benefit consumers. Moreover, nobody would be obliged to buy chlorinated chickens. “Organic” American chicken is not dressed in PRTs. All in all, chlorinated chicken is a paltry concern compared to what else will be on the negotiating table.