Another reason to eat less or no meat — chlorine-washed food can actually cross-contaminate a kitchen.
The chlorine washing of food, the controversial “cleaning” technique used by many US poultry producers who want access to the British market post-Brexit, does not remove contaminants, a new study has found.
The investigation, by a team of microbiologists from Southampton University and published in the US journal mBio, found that bacilli such as listeria and salmonella remain completely active after chlorine washing. The process merely makes it impossible to culture them in the lab, giving the false impression that the chlorine washing has been effective.
Apart from a few voluntary codes, the American poultry industry is unregulated compared with that in the EU, allowing for flocks to be kept in far greater densities and leading to a much higher incidence of infection. While chicken farmers in the EU manage contamination through higher welfare standards, smaller flock densities and inoculation, chlorine washing is routinely used in the US right at the end of the process, after slaughter, to clean carcasses. This latest study indicates it simply doesn’t work.
Currently, chlorine-washed chicken is barred from entry to the EU on animal welfare grounds and has become a contentious issue for opponents of liberal trade deals with the US post-Brexit.
Previous studies with similar findings have been dismissed by the US poultry industry as producing “laboratory-only” results with no relevance to the real world. “We therefore tested the strains of listeria and salmonella that we had chlorine-washed on nematodes [roundworms], which have a relatively complex digestive system,” said Professor William Keevil, who led the university team. “All of them died. Many companies and scientists have built their reputations promoting anti-microbial products. This research questions everything they’ve done.”
The study tested contaminated spinach, but Keevil insists the findings apply equally to chicken. “This is very concerning,” he said. The issue, he argues, is less to do with the chicken itself, the contamination of which can be managed by thorough cooking. “It’s that chlorine-washed chicken, giving the impression of being safe, can then cross-contaminate the kitchen.”