Chlorinated chicken imports have emerged as a defining test of whether the UK will uphold its food standards in post-Brexit trade negotiations, with government officials actively considering how to respond to US pressure to accept such products alongside other chemically processed meats. Documents obtained under freedom of information requests have confirmed that British officials have been briefed on the possibility of allowing these imports, even as ministers publicly insist they have “no plans” to do so and that food standards will not be weakened in any trade deal with the United States.
The issue has become a potent symbol of a wider struggle between the UK’s traditional “farm-to-fork” regulatory philosophy and the US approach, which prioritises end-product safety through chemical interventions. Under EU law, which the UK followed until Brexit, only cold air and water were permitted for decontaminating poultry. The US, by contrast, routinely treats chicken carcasses with antimicrobial chlorine rinses after slaughter, aiming to kill or suppress bacteria such as Salmonella and Campylobacter. The EU banned imports of US poultry treated in this way in 1997, and the UK adhered to that ban. Now, with the UK renegotiating its trade relationships, the US has characterised Britain’s standards as “non-science-based” trade barriers, and former US officials have suggested that British consumers would prefer American products if they tasted them.
Yet the scientific evidence raises serious questions about whether chlorine washing makes chicken safer. A 2018 study found that applying chlorinated water provides what the authors describe as “illusory reassurance”. The treatment is not an effective disinfectant; rather, it blocks the customary bacterial culture test by which the presence of harmful bacteria should be detectable. Bacteria exposed to chlorine can enter a viable-but-nonculturable (VBNC) state, meaning they remain alive and capable of causing illness but cannot be grown on standard laboratory plates. This gives a false impression of effectiveness. Research also indicates that while chlorine can reduce Campylobacter loads, its efficiency depends heavily on the initial bacterial concentration. At higher loads, some strains are inhibited but not eradicated, and there is potential for resuscitation. Other studies suggest that chlorine washing, at the concentrations used globally, may not significantly enhance the removal of bacteria from broiler carcasses at all.
Critics argue that the practice allows producers to compensate for or mask poorer hygiene and animal welfare standards earlier in the food chain. The US system focuses on cleaning up contamination after slaughter; the UK and EU approach aims to prevent contamination from arising in the first place, through rigorous standards at every stage from rearing to processing. This fundamental divergence in regulatory philosophy lies at the heart of the chlorinated chicken debate.
That difference also helps explain why rates of microbiological food poisoning are significantly higher in the US than in the UK and the EU, according to some analyses. The US Centers for Disease Control and Prevention estimates 48 million foodborne illnesses annually, compared with the UK Food Standards Agency’s estimate of 2.4 million – a rate more than four and a half times higher. The US death rate from Salmonella is far higher than in the UK. However, other comparisons based on laboratory-confirmed cases suggest higher rates of Campylobacter and Salmonella in the UK than in the US, illustrating the complexity of cross-national food safety data. Nonetheless, Campylobacter remains the most common bacterial cause of food poisoning in the UK, with reported cases rising in England in 2024.
The severity of such infections should not be underestimated. One reader has described contracting campylobacteriosis while one month pregnant. “It did not cause diarrhoea but rather long-lasting severe lower abdominal pain,” she wrote. When eventually diagnosed, she was put on a high dose of an unpleasant antibiotic, leaving her with a tinny taste and no appetite for weeks. “I was over five months pregnant before I began to feel remotely normal.”
Erik Millstone, emeritus professor of science policy at the University of Sussex, and Tim Lang, emeritus professor of food policy at City St George’s, University of London, have argued that accepting US imports of chlorinated chicken and other processed products would make the UK’s food supply “significantly less safe”. In their view, it would be reckless for any UK government to relax the prevailing import restrictions unless American authorities can demonstrate that their products are at least as safe as those achieved by UK and EU producers. Professor Millstone’s research focuses on the role of scientific expertise in managing technological risks in the food chain; Professor Lang founded the Centre for Food Policy at City and has advised the World Health Organization and the UK government on food systems. Their judgment carries weight.
Public opinion is firmly against any dilution of standards. A 2020 YouGov poll found that 80% of Britons considered the import of chlorine-washed chicken unacceptable. Cross-party MPs have warned of a “cruelty loophole” whereby practices banned in the UK could be allowed in imported products. And while some have argued that allowing US chicken imports could lower prices for British consumers – one study suggested a potential reduction of 21% – the trade-off, many believe, would come at the cost of food safety, animal welfare and consumer confidence.
Approximately 5% of US chickens are currently treated with chlorine, though some parts of the American industry are moving towards alternatives. The UK government has insisted that chlorinated chicken and hormone-treated beef remain illegal to import. Yet the fact that officials have been actively preparing for the possibility of accepting such products suggests that, behind the public assurances, the door has not been firmly closed. Chlorinated chicken, as Professors Millstone and Lang put it, is a test case – one that will determine whether the UK sacrifices its standards for commercial and political advantage, or holds the line.