This has resulted in a furore on FaceBook, though the concern about chlorine-washed chicken is a little surprising. Chlorine rinses are used extensively in the food industry to reduce surface contamination on vegetables, during chicken processing and for sanitation of equipment during food processing.
Of course, chlorine is also used in water treatment for decontamination of potable water supplies where UV treatment is not used, perhaps for cost cosiderations.
Over the years, a lot of work has been done on the effects of chlorine in foods. At the levels used for practical decontamination, there is no risk to human health, though some chemical changes are inevitable.
If you are keen to follow up on this, The Institute for Environmental and Scientific Research Limited, (ESR) in New Zealand produced a report in 2008 for the New Zealand Food Safety Authority: Client Report FW0883 CHLORINATED COMPOUNDS FORMED DURING CHLORINE WASH OF CHICKEN MEAT.