Speaking with an industry associate recently, we were discussing the use of diatomaceus earth. A concern was expressed about using diatomaceous earth. I thought, maybe folks are confused by the many different types of diatomaceous earth.
For pest control, the only type of diatomaceous earth you should be using is “Food Grade” diatomaceous earth. “Pool Grade” diatomaceous earth has been chemically processed and is carcenogenic. But food grade diatomaceous earth is an OMRI listed product considered by the FDA to be safe for use indoors and out. It is called “food grade” because it is used that way, including for the use of gastrointestinal parasites.
You can find many articles on the internet about this subject. Wikipedia (diatomaceous earth) is still perhaps the best source for sound information on most topics, including this one. We have experimented with the use of food grade diatomaceous earth in the Hearts Pest Management organic pest control program. We have since dropped it because it is very dusty and bulky, not because of any health issues. Also, we believe it is more appropriate for weekly applications than the more realistic monthly applications. I am also not sure how well it holds up during rainy seasons or when used in irrigated landscapes. Additionally, my observation is that insects find their way around it. Even if a few are sacrificed, the insect imperative to get to a food source far exceeds the ability of this barrier to deter them.
Sadly, we have found many people who complain of mite bites going to extremes in DIY self-treatment. We examine the subject, “Am I Crazy?” on our Bugs In My Bed website. I don’t know if these folks are crazy or not, if they have delusional parasitosis or not, but one sure sign that you have an insect obsessed client is when you see diatomaceous earth covering the entire house, caked onto the couch, floors, bed, walls. When you see people going to this type of extreme use of diatomaceous earth, be sure to ask them what other products they are using. You may find that they have purchased all sorts of pesticides for use indoors, even in their wash!