There are a few mineral products that are used against veterinary parasites: borax, silica (diatomaceous earth) and sulfur. Mineral or inorganic means that unlike most other insecticides thay are not of organic origin.
They are mostly solids (crystalline, powders, etc), not volatile and usually rather stable. They are very scarcely used as antiparasitics in veterinary medicine. They are considered as quite safe for humans and domestic animals.
Borax for the control of veterinary parasites
Borax (also known as sodium borate, sodium tetraborate, or disodium tetraborate) is a salt of mineral origin. The powder is white and is soluble in water. It is abundantly used in the wood and metallurgic industry, in detergents and cosmetics, etc. It is also used in a few products for controlling some insects, e.g. fleas, flies and ants.
It is used e.g. in traps for flies or cockroaches to kill the trapped individuals. There are also some reports on borax used to treat garbage to make it less attractive for flies.
Use against fleas is mainly for treating carpets or soils contaminated with flea eggs or larvae. More than having an insecticidal effect it just causes eggs and larvae to dry out and die before completing development to adult fleas. There are no reports on a potential usage in flea-contaminated soils in livestock premises, but it could be an alternative to synthetic larvicides used for this purpose.
Acute oral rat LD50 is 2660 mg/kg.
So far there are no reports on parasite resistance to borax, which is not surprising considering its very scarce veterinary use and its physical more than chemical mode of action.
Silica for the control of veterinary parasites
Silica gel, diatomaceous earth and other silica products are capable of absorbing a lot of water (i.e. they are hygroscopic) and other liquids. When they come in contact with insects they absorb their cuticular lipids, which accelerates the loss of body water and kills them by dessication.
They are moderately used against some domestic pests (cockroaches, mealworms, etc.). Use against veterinary parasites is very rare. There are some silica products to combat poultry mites and sheep lice in some countries. A few silica products are also sold for killing pet fleas off-animal, i.e. for treating their environment (carpets, upholstery, etc.). Such products do effectively reduce the parasite populations to some extent, but they are insufficient to suppress them.
So far there are no reports on parasite resistance to silica, which is not surprising considering its very scarce veterinary use and its physical more than chemical mode of action.
Sulfur for the control of veterinary parasites
Sulfur has been used for centuries as insecticide and fungicide in agriculture and veterinary medicine, and also against domestic pests.
Nowadays it is still used in agriculture (e.g. in wine and fruit growing), often in integrated programs together with other organic pesticides. Usage against veterinary parasites is irrelevant.
So far there are no reports on parasite resistance to sulfur, which is not surprising considering its very scarce veterinary use.