Safety of Boric Acid As An Insecticide

Most industry experts agree that Boric Acid is one of the safest and least toxic insecticides, yet is most effective in getting rid of insects. That’s a pretty efficient combination. Safe to people, lethal to insects including including cockroaches, termites, ants, and fleas as well as other pests with exoskeletons.

How Safe is Boric Acid?

According to the EPA toxicity rating standard, boric acid is only slightly more orally toxic than table salt. There is however much controversy over its safety. An Internet search will reveal conflicting information. Some may be true, some false and some exaggerated.

The best explanation is how the Environmental Protection Agency (EPA) determines its toxicity rating of an insecticide. It uses an LD50 rating which is a benchmark measurement of acute oral toxicity exposure to rats where a “lethal median dose” of an insecticide would likely kill 50% of a population of rats. Hence “LD50”.

A dose is expressed in milligrams (mg) of an insecticide per kilogram of the body weight of a rat. The lower the LD50 dose, the more toxic the insecticide. The higher the LD50 dose, the less-toxic the insecticide.

Therefore, a pesticide with an LD50 value of 10mg/kg would be 10 times more toxic versus 100mg/kg. A value of 100mg/kg would be 10 times less toxic versus 10mg/kg.

The following LD50 comparatives of common substances to boric acid illustrates the relative oral low-toxicity of boric acid. It is important to note that the comparatives assume 100% concentration of the product. In most cases as an insecticide, boric acid would be highly diluted in an ant or cockroach bait with the majority of ingredients a combination of a food attractant and inert ingredients.

  • Aspirin. 1000
  • Boric Acid. 2660
  • Table Salt. 3000
  • Baking Soda. 4200


More Information About The Low Toxicity of Boric Acid

The following sources provide more detailed information relevant to the safety of boric acid. This will help you make well-informed decisions about using boric acid as an insecticide.