Under an OSHA Hazard Communication Standard, based on animal chronic toxicity studies of inorganic borate chemicals, boric acid and/or borates are Hazardous Materials. California has identified boric acid as a hazardous waste. The above information is taken from Material Safety Data Sheet (MSDS) 25-80-2320 (Section 2 and 13) supplied by U.S. Borax Inc. (the major supplier of borax to many industries). [QUOTE]
[QUOTE]Boric acid is generally known as a desiccant; in other words, it kills by removing the moisture from the body of the target pests, causing severe dehydration which will affect electrolyte metabolism with the potential of metabolic acidosis. In fact, boric acid is a stomach poison normally ingested, along with the fact that it can also enter the blood by inhalation. Boric acid is an acid. Acid will decrease the pH level with the possible side effects of renal, respiratory, and cardiovascular failure. Symptoms and signs of boric acid poisoning are nausea, vomiting, diarrhea, headache, dysphagia, cold sweats, dyspnea, muscular debility, scarlatinal eruptions, subnormal temperature, cardiac weakness, cyanosis, coma, collapse, etc. Boric acid is 3 parts hydrogen, 1 part boron, and 3 parts oxygen. Recently U.S. Borax discovered that boric acid contains traces of arsenic. Before California Prop 65 there were few, if any, human studies on boric acid. When human studies were requested from U.S. Borax they said they were unable to supply us with any at that time. But in the late 1980's they had started doing new and extensive toxicity tests on rats and mice as a result of California Prop 65. As a result of these tests, they discovered a decrease in sperm count and the stopping of fetal and embryonic development in rats and mice. In early 1993, U.S. Borax had asked for, and has received, additional time to complete their laboratory studies from the State of California.

Boric acid contained traces of arsenic, a chemical known to the State of California to cause cancer. U.S. Borax was able to use the EPA de minimus policy, which accepts that zero is not absolute, but very, very small to remove arsenic from its Material Safety Data Sheet. I personally do not see any risk with the trace amount of arsenic at 1 part per million in boric acid and/or borates if used in an appropriate application method. But, not where there will be constant direct contact.

Boric Acid is one of the safest pesticides if used correctly.

By Michael R. Cartwright, Sr.