Canada and Australia are among the other countries that chlorinate chicken, Canada chlorinates beef as well. It happens in many other countries as a cheap and effective way of preventing salmonella among other things. Chlorine levels can vary, in most countries the chlorine levels are about the same as in tap water.
The EU are on record as stating they have no safety concerns re chlorinated chicken, the reason they have banned US chicken is over animal welfare concerns, the number of chickens kept in cages etc, overcrowding etc which can lead to less sanitary conditions, chlorinating resolves the sanitary concerns, the viewpoint of the EU is that if the birds are in less crowded conditions, chlorinating is not required, although salmonella is on the increase in Europe.