We frequently get questions about the various borate products on the market to control insects around the home. These products are used to control ants, cockroaches and structural pests like carpenter ants, powderpost beetles and dry-rot fungi.
Borates offer a low toxicity alternative to conventional insecticides, but are slow acting and may take several weeks to be completely effective. Borates are also generally long lasting, if kept dry. And, borates are generally not used outdoors because of they are soluble in water. Borate is primarily an insect stomach poison and fungicide. Stomach poisons must be eaten by the pest to be effective.
Timbor and Bora Care (and a few others) are products for structural pest control (termites, carpenter ants and wood-boring beetles). Timbor is a powder of 98% disodium octaborate tetrahydrate, a sodium salt of boric acid, and Bora Care is a 40% solution of the same compound plus ethylene glycol.
Timbor can be used to treat wall voids for carpenter ants and/or cockroaches, silverfish, etc. Timbor powder may also be dissolved in water and applied as a solution. Bora Care, on the other hand, is always applied as a spray to protect wood against chewing insect attack (carpenter ants, termites, wood boring beetles, etc.) and dry-rot fungi. Bora Care contains ethylene glycol which may help in penetration of wood fibers.
Borate powder ("Roach Pruf", "Roach Powder") is an excellent alternative to conventional insecticides for cockroach control as well. The powders can also be formulated as a homemade ant bait. My own experience is that borate powders, when used correctly, are very effective but slow acting. When used to dust wall voids, it will eliminate carpenter ant colonies and prevent re-infestation. Sometimes borate treatments are combined with a faster knockdown insecticide like pyrethrum.