Diatomaceous Earth (DE)

Recently a conversation came up in a poultry forum about using DE in chicken feed and why some was okay for consumption and others has the usual 'dangerous to animals' disclaimer. Here is an interesting article posted by a company the 'manufactures' DE and why some is considered a dangerous insecticide and others is not. I've posted the part specific to the categorization as an insecticide however I'd recommend reading the entire article.

With the help of Arizona State University, the Perma-Guard product was patented as a “wormer”. Unlike most worming products, the Perma-Guard product was not a deadly poison. Strangely, this caused a problem. You see, once you claim that a product can kill bugs, it has to be registered with the EPA, classified as an insecticide, and sold under a different label. So today, our pure, food-grade, organic diatomaceous earth is sold in two bags. One bag is labeled "Fossil Shell Flour," with no warnings of any kind required on the packaging. It is certified organic, is perfectly safe to add to feed or mix with water and drink, and it is as safe as spring water. The same diatomaceous earth, is packaged in another bag that says it kills bugs. This package, called "Grain Protectant", and is required to have warnings on the label, like “CAUTION - Keep out of the hands of children.” DE in this package could be mixed with stored grain. A single treatment would keep the grain absolutely free of bugs and free of poison residues — indefinitely! With the Grain Protectant label, it is an insecticide and must not be fed to animals. (huh???)