More good news post Brexit

You have that backward.
American meat packers are required to bleach their chicken because it has such high levels of salmonella after it has gone through the packing process.
EU standards instead insist that salmonella levels are kept to a higher standard through better practice instead.
This has the added bonus of increasing welfare standards for the chickens with cleaner environments etc.
It's the same thinking which means Americans have to keep their eggs in the fridge but they are on normal shelves in the supermarkets here. EU standards require regular flock testing to ensure eggs are salmonella free whereas the Americans put them in fridges.
Same with the levels of rodent faeces and dead insects in products.
In the US they regulate to a certain percentage of rat poo in your orange juice. 5mg per litre or whatever. 
In the EU they regulate to a standard of zero impurities.

It doesn't matter what part of the globe chicken is harvested from the fact is that salmonella is present on the dead flesh at the rate of 14% and Chlorination reduces that to 2%. Its nothing to do with the way meat is packed or the way it is handled.

In America.

Here the levels are kept safe without having to bleach the meat.

In short because lettuce is grown in bug riddled soil

The long story here:  www.which.co.uk/news/article/chlorine-washed-chicken-vs-chlorine-washed-salad-leaves-whats-the-difference-aMipZ5W3EtGW 

'Salad leaves can pick up bacteria such as salmonella, norovirus and E coli from soil.



In bagged salads labelled as pre-washed or ready to eat, the leaves have to be treated to remove the bacteria and ensure they're safe to eat. . . .


The leaves can't be heated or frozen as this would ruin them, which is why they're washed.To minimise bacterial contamination and the risk of food poisoning, farmers in the UK and EU legally have to follow high welfare and production standards throughout the system, as opposed to relying on a single decontamination stage.



This is known as a farm-to-fork approach and includes minimum allowances for space, light and ventilation in chicken housing, giving birds space to move and behave normally.



Chicken houses must also be cleaned thoroughly and the litter replaced between flocks.



But in the US, similar laws or regulations don't exist.'

The problem is banning chlorination is a non intuitive way of removing salmonella etc from the food chain. But it does seem to work.

As for Chlorine in tap water think about how many kidneys (and intestines) that water has passed through before it gets to your tap. That said it makes the water taste foul so I never drink it unfiltered.