1. What is boron?
Boron is a naturally occurring element. In nature it is found combined with oxygen and other natural elements forming several different compounds called borates. Borates are widely distributed in nature, being present in the oceans, sedimentary rocks, coal, shale and some soils. The average concentration of boron in rocks varies from 5 mg/kg in basalts to 100 mg/kg in shales. In the ocean, the boron concentration is approximately 4.5 mg/liter.
The most important borate products and minerals on the market are borax pentahydrate, borax, sodium perborate, boric acid, colemanite, and ulexite.
Boric acid and many borates are soluble, at low levels, in water and in biological fluids such as saliva and blood. When boric acid or borates are dissolved in these liquids, which have a near-neutral pH, the main molecular species present is boric acid with a small amount of borate anion. The amount of borate anion is greater in more alkaline (or higher pH) solutions.
Sodium perborate, however, is different from the other borates. It reacts with the water in which it is dissolved to give hydrogen peroxide plus metaborate. Because it forms hydrogen peroxide, which has oxidising properties, sodium perborate has chemical and toxicological properties that are somewhat different from those of the other borates.
The method used to measure the boron concentration is quite important. More...
Click here for information on measuring methods and units for boron