Another questionable chemical in many manufactured diets for parrotsCOPPER SULFATE AS AN INGREDIENT IN MANUFACTURED PARROT DIETS by Sally Blanchard(Description from Wikipedia) Some caution is required in handling copper sulfate, as it is toxic and acidic, and it can pose health risks to living organisms. Copper sulfate is an irritant. The usual routes by which humans can receive toxic exposure to copper sulfate are through eye or skin contact, as well as by inhaling powders and dust. Skin contact may result in itching or eczema. Eye contact with copper sulfate can cause conjunctivitis, inflammation of the eyelid lining, ulceration, and clouding of the cornea. Upon acute oral exposure, copper sulfate turns to be only moderately toxic. According to studies, the lowest dose of copper sulfate that had a toxic impact on humans is 11 mg/kg. Because of its irritating effect on the gastrointestinal tract, vomiting is automatically triggered in case of the ingestion of copper sulfate. However, if copper sulfate is retained in the stomach, the symptoms can be severe. After 1–12 grams of copper sulfate are swallowed, such poisoning signs may occur as a metallic taste in the mouth, burning pain in the chest, nausea, diarrhea, vomiting, headache, discontinued urination, which leads to yellowing of the skin. In the case of copper sulfate poisoning, injury to the brain, stomach, liver, kidneys may also occur. Used as an herbicide, fungicide and a pesticide. - As with Menadione (that is banned in human food and pet foods in several countries because it is considered a carcinogen) - the pet food manufacturers will say that there is not enough of this chemical in the foods to cause any problems but they want you to feed their foods to your dogs, cats, and birds as a total or near total diet for the rest of its life. People are fools if they believe the pet industry hype about their foods being healthy.- Copper Sulfate is listed as an ingredient of Harrisons, Hagen, Kaytee Exact Rainbow, all Pretty Bird Manufactured Diets, Scenic Bird Food, ZuPreem Natural, ZuPreem Avian Entrees, ZuPreem Bird Cookies, and ZuPreem FruitBlend parrot diets when I researched them. Check the ingredient list in the pellet you are feeding.