Two diatomaceous earth grades are commercially available and have specific differences. The food grade variety has many uses and is safe for both human and animal consumption. The pool grade, also known as garden grade diatomaceous earth, is toxic to people and animals, and should be used only in pools.
Food grade diatomaceous earth grades are the most common and have many applications. They can be mixed with grain that is stored for both animal and human food to repel mealworms as well as other pests and to prevent the grain from caking. They are safe to use as indoor insecticides and are also very effective when used outdoors to repel and kill insects. They work by creating tiny abrasions as the insects crawl over them, which in turn causes loss of body fluids, thereby resulting in dehydration and death.
Diatomaceous earth is also an effective wormer for livestock and household pets. It can be applied to cats and dogs to repel fleas and ticks; cats are dewormed as they lick and groom themselves and ingest the particles. It also kills flies and their eggs. Indoors, it can be used to repel and kill bedbugs, cockroaches, crickets, silverfish, and many other unwanted insects.
Although not common, some people do eat this natural product. It contains many trace minerals and is thought to be a cure for just about any ailment. In addition, the substance may have value as a colon cleanser and overall detox agent. It is frequently mixed with juice to improve the taste. Most of us have eaten diatomaceous earth in small amounts without realizing it because it is in many or our grain products.
Pool grade diatomaceous earth can be used to treat pools and as an insecticide in gardens and yards. It is utilized much the same as the food grade type and produces similar results. Pool grade diatomaceous earth, however, often contains other pesticides and poisonous chemicals. It is best to use the food grade for everything except pool filters.
Both diatomaceous earth grades are made from ground skeletal remains of algae that live in both fresh and salt water, but they can be harmful if applied incorrectly. Diatomite forms when this product is ground, which is nearly pure silica. In addition to the chemicals added to the pool grade, the dust from the diatomite in both diatomaceous earth grades can be damaging to the lungs if inhaled. It is also very irritating to the eyes and drying to the skin. Gloves should be worn when using this product.