At first when I read the label about not growing them, I thought they must have been genetically modified (transgenic) but they weren't and that's what made me investigate further.

There appears to be a couple of chemicals commonly used. One is maleic hydrazide, also known as 1,2-dihydropyridazine-3,6-dione. The other is Chlorpropham.

http://www.decodedscience.org/chemic...e-growth/45175
Chemical treatment of potatoes to inhibit eye growth

It appears that washing isn't enough as the chemical treatment penetrates into the centre of the potato.

http://toxnet.nlm.nih.gov/cgi-bin/si...rm+@DOCNO+1162
maleic hydrazide

http://archive.epa.gov/pesticides/re...f/0271fact.pdf
EPA Gov - Chlorpropham