You may not be able to imagine that borax, this humble insecticide and laundry detergent, has the potential of singlehandedly bringing down our entire economic system. But you do not need to worry, the danger has been recognised and the necessary steps are already being taken to defuse the situation. I will start with the basics and you will understand what I mean as the story unfolds.
Borax is a naturally occurring mineral commonly mined from dried salt lakes, and is the source of other manufactured boron compounds. The main deposits are in California and Turkey. Chemical names are sodium tetraborate decahydrate, disodium tetraborate decahydrate, or simply sodium borate. This means it contains four atoms of boron as its central feature combined with two sodium atoms and ten molecules (or sometimes less) of crystallisation water – decahydrate means 10 water molecules, pentahydrate 5, and anhydrate or anhydrous borax means no crystallisation water; chemically it is all the same.
Borax is commonly sold as technical or agricultural grade with 99 to 99.5% minimum purity. Potential impurities consist of sodium, potassium, calcium, chloride, bicarbonate, carbonate, sulphate and phosphate but not toxic or heavy metals. This grade includes the borax commonly used as household cleaner. Pharmaceutical grade is not noticeably purer or better.
Borax is the sodium salt of the weak boric acid. Because sodium is more strongly alkaline, this makes a solution of borax strongly alkaline with a pH between 9 and 10 (pH 7 is neutral). When ingested, it reacts with hydrochloric acid in the stomach to form boric acid and sodium chloride. The boron content of Borax is 11.3% while for boric acid it is 17.5% or about 50% higher. Ingested boron compounds are rapidly and nearly completely excreted with the urine. Formerly boric acid was widely used as a preservative in foods but is now banned for this purpose in most countries, and is also banned from public sale in Australia.