EDTA (ethylenediaminetetraacetic acid) is often added to food to remove the problems caused by impurities leftover from the soil or from machinery during the harvesting and processing stages. EDTA binds with the impurities (trace metals) and helps prevent the premature decomposition of food. EDTA is also used to remove metals during heavy metal poisoning treatments.

The danger connected to EDTA is that it is widely used and has been noted to produce reproductive or developmental toxicity when exposed in large amounts to humans.

To learn more, go to:
http://www.3dchem.com/molecules.asp?ID=89
http://ijt.sagepub.com/cgi/content/abstract/21/2_suppl/95