What are BHA, BHT, and Ethoxyquin?
In general, foods will spoil without some form of temperature control or preservatives. BHA, BHT, and ethoxyquin are chemical antioxidants designed to extend the shelf life and reduce fat spoilage (rancidity) of pet foods and pet treats. Chemical additives and artificial preservatives such as BHA, BHT, and ethoxyquin may cause dry skin, allergic reactions, dental disease, and poor health, as well as stimulate adverse effects on liver and kidney functions.

http://chemistry.about.com/od/foodcooki ... atives.htm
http://www.beyondpesticides.org/transfo ... olicy/?p=5
http://www.aplus-flint-river-ranch.com/ ... ?win=small
http://www.canine-epilepsy-guardian-ang ... of_bha.htm
http://articlesadv.com/topic/bht-bha-ethoxyquin/
http://www.viewpoints.com/Kirkland-Dog- ... 7934/quote