One wonders whether someone is measuring chickens, because something fowl is afoot: after October 31, the UK will no longer be held to the EUs 1997 ban on chlorine-based pathogen reduction

treatments (PRTs). Across the European Union, food standards currently allow goods and methods that have been proven safe. Hence, poultry is air-chilled in EU countries. After Brexit,

however, the US will be top of the list for a UK trade deal. As the US  is the second largest exporter of chicken in the world, we can expect a major chip on the trade deal bargaining table

to be poultry. US food standards disallow methods that have been proven unsafe – the opposite of the EU. Poultry from the US is disinfected using chlorine, whether via spraying or dilution

deal would include poultry sanitised with chlorine, insisting there is “no scientific basis” to the fears. You can’t help noticing a vulturish aspect to US perception of Brexit. Even its TV

news segments have an eerie habit of describing the $300 million potential in EU exports as a “cost”, as though less-than-maximum profit is money not in the coffers of American manifest

destiny. According to Dr Thomas Wright of the Brookings Institution, Trump thinks this way too: “The worse the relationship between the UK and the EU, the more opportunity there is for the

United States. He has, in effect, a predatory policy towards Brexit.” It is therefore worth clarifying the science, if only to prepare against inelegant premises and arguments offered in bad

faith. Firstly, no one who has been in the same room as a relevant scientific paper argues that chlorine itself is dangerous. Across the UK and EU, all bagged salads are washed with the

stuff. Only rare hypochlorite treatments carry threadbare and scarcely valid evidence of carcinogenic by-products. As far as any sensible scientific consensus in concerned, chlorine is fine

to ingest in the trace amounts that reach the public. However, there are reasonable objections to what chlorine covers up, both at the macro and microbiological levels. Last year, the

University of Southampton published a study that highlighted the risk of viable but non-culturable (VBNC) microflora. Organisms such as listeria and salmonella can protect themselves when

exposed to disinfectants like chlorine, by entering a dormant state. When they reach this dormant state they become ‘viable but non-culturable’. This means they are undetectable to quality

control labs, but are later revived by the nutrient feast in the human gut. This flashes a briny middle finger to the joint 2008 FAO/WHO report that concluded with breezy reassurance: “At

this point, chlorine-containing compounds remain the most common and effective choice for controlling bacterial contamination during poultry processing.” At first glance it would appear that

chlorine beats air-chilling in controlling the spread of carcass-borne pathogens, because a chlorine-treated sample would appear less infected than an air-chilled one. This was indeed the

metric for treatment effectiveness in the FAO/WHO report. All it may have shown, though, is that chlorine is better at disguising the problem. A 2013 Johns Hopkins study sampled carcasses

from six US states. They found significant levels of arsenic (used to make flesh pinker), antihistamines (keeps birds calm and flesh more tender), caffeine (keeps birds awake and eating),

ketamine, and steroids. The lesson we might take here is that chlorine may not be the issue. This is the EUs fear: that any end-of-line sanitisation method that appears to be so effective

leaves too much leeway for poor livestock conditions and disorganised abattoirs further up the production chain. Whether this is true or not, any agricultural policy not focused on optimum

farming conditions in the first place will never be ideal. It is hard to say. Beyond these studies, there aren’t many concrete objections to chlorine-based PRTs. The BBC found this out the

hard way. Earlier this year, it was called out by fact-checkers for using different studies from the US Centers for Disease Control and Prevention and the UKs Food Standards Agency to

suggest that food poisoning is more common in the US than the UK. It probably is, but the ephemeral variables of epidemiological studies make such data sets incomparable. We don’t really

understand the full rewards or risk of chlorine-based PRTs. But, even if the US strong-arms the UK into becoming its new exports darling, it is worth remembering who rules the market: us.

The consumers. We can insist on standards of our own.