This question was posed on Slate today in response to one of the economic issues addressed in Barak Obama's recent visit to Europe. Apparently the current European ban on U.S. chicken imports costs the U.S. close to $200 million annually. The issue isn't food safety in this case, it's supposedly taste. The chlorine is meant to prevent bacterial build-up, but a University of Georgia Study from August 1999 indicates that processed chicken receiving the chlorine treatment starts tasting funny after sitting in the fridge for a few days, while non-chlorinated chicken does not.
What's the lesson here? I'm not sure. I'd rather not have bleached chicken, but I guess I'll sleep easier knowing that if I eat quickly I won't notice.