What Is Borax and How Is It Used?

Borax is a natural mineral with a chemical formula Na₂B₄O₇ • 10H₂O. It is also known as sodium borate, sodium tetraborate, and disodium tetraborate. Borax is one of the most important boron compounds. The International Union of Pure and Applied Chemistry (IUPAC) name for borax is sodium tetraborate decahydrate.

Borax Versus Boric Acid

Borax and boric acid are two related boron compounds. While borax is a natural mineral mined from the ground or collected from evaporated deposits, boric acid is the purified chemical (H₃BO₃) that results from processing borax. Borax is a salt of boric acid. While there are some differences between the compounds, either version of the chemical will work for pest control or making slime.

What Products Contain Borax

You can find borax in laundry boosters, hand soaps, and some kinds of toothpaste. It is also a sole, primary, or secondary ingredient in these products:

• 20 Mule Team Borax (pure borax)
• Powdered hand soap
• Tooth bleaching formulas (check labels for borax or sodium tetraborate)

Borax Uses

Borax has many uses on its own, plus it is an ingredient in other products. Here are some ways that you might use borax powder and pure borax in water:

• Insect killer, particularly in roach-killing products and as a moth-preventative (ten percent solution on wool)
• Fungicide
• Herbicide
• Desiccant
• Laundry booster
• Household cleaner
• Water softening agent
• Food additive as a preservative (banned in some countries)

Borax is an ingredient in several other products, including:

• Buffer solutions
• Flame retardants
• Teeth bleaching products
• Glass, ceramics, and pottery
• Enamel glazes
• A precursor for boric acid
• Science projects such as green-colored fire, slime, and borax crystals
• Analytical chemistry borax bead test
• Flux for welding iron and steel

How Safe Is Borax?

Borax in the usual form of sodium tetraborate decahydrate is not acutely toxic, which means a person would need to inhale or ingest a large amount to experience adverse health effects. Related to pesticide use, borax is one of the safest chemicals available. A 2006 evaluation of borax by the United States EPA found no signs of toxicity from exposure to the chemical and no evidence of cytotoxicity in humans. Unlike many salts, skin exposure to borax does not produce skin irritation.

However, this does not make borax categorically safe. The most common problem with borax exposure is that inhaling the chemical's dust can cause respiratory irritation, particularly in children. Ingesting large amounts of borax can cause nausea, vomiting, and diarrhea. The European Union (EU), Canada, and Indonesia consider borax and boric acid exposure a potential health risk, primarily because people are exposed to it from many sources in their diet and from the environment. The concern is that overexposure to a chemical generally deemed safe could increase the risk of cancer and damage fertility. While the findings are somewhat contradictory, children and pregnant women should limit their exposure to borax if possible.