Boron Essentials

A fundamental part of life on Earth

As one of the chemical elements that make up our planet, boron is all around us—in soil and water, plants and animals—in trace amounts. Aside from... Watch the video


Boron is a naturally occurring element in soil, where it originates from minerals in the earth’s crust. Large deposits formed over many years, with high concentrations of borates encapsulated in nonpermeable layers of clay. As a water-soluble element, boron’s availability and boron levels in soil depend on several factors:

  • The solubility of boron in the parent rock
  • The physical and chemical characteristics of the soil
  • The availability of water moving through the soil

The total boron level in soil can be categorized as low boron (less than 10 mg B/kg of soil) or high boron (around 100 mg/kg). The average overall concentration of boron in all soil ranges from 10 to 20 mg/kg; extremely high-boron soils are rare.

It’s important to note that not all the boron that is present is available (for use by plants, for example). The available level of boron can range anywhere from 0.1 to 3 mg/kg of soil. In some parts of the world, soil sits on top of rock with a high boron content, which can create boron-enriched topsoil and groundwater. However, most boron is either locked inside insoluble minerals or firmly attached to other components, such as clay or organic matter. For this reason, boron deficiency is more widespread than boron enrichment.

In the atmosphere, boron has been detected in measurable (albeit minimal) quantities in evaporation from seawater; evaporation of rain, snow, and hot springs; and in industrial airborne dust. In rain and snow, for example, boron has been reported in concentrations of between 0.002 and 0.1 mg B/L.

Boron Element


People didn’t know about mineral nutrients when they first started growing crops more than 10,000 years ago. Only during the past century or so have scientists and farmers discovered the seven essential micronutrients—boron among them—that plants need to grow.

At the cellular level, boron is integral to a plant’s reproductive cycle. Boron controls flowering, pollen production, germination, and seed and fruit development. As a micronutrient, boron also acts as a fuel pump, helping move sugars from older leaves to new growth areas and root systems.

Plants get the boron they need from soil and water. In fact, they can’t live without it. For humans, experts agree that boron is nutritionally important, and mounting evidence suggests that boron may be an essential element in our diet as well.

Each year, millions of tons of industrial borates are mined, processed, and distributed around the world for use in agriculture, construction, industry, and energy. Yet rain, volcanic activity, condensation, and other atmospheric activities redistribute at least twice that amount. On a global basis, boron moves through the atmosphere at a rate of 5 to 7 million tons per year.

Boron, Borates,
and Borax

Borates are inorganic salts that contain boron. Although boron is an essential element, it doesn’t exist by itself in nature. Instead, you’ll find it in various combinations with oxygen and other elements, forming substances such as boric acid (boron, oxygen, and hydrogen), calcium borate (boron, oxygen, and calcium), sodium borate (boron, oxygen, hydrogen, and sodium), or lithium borate (boron, oxygen, and lithium).
Borax is often used to refer to sodium borate—and the term has become synonymous with U.S. Borax and our 20 Mule Team® borax products as we have been one of the world’s primary sources of refined boron for more than a century.
Boron is an element, represented by the capital letter B—the fifth element on the periodic table.


Whether in the food on your table, the car you’re driving, or clothes you’re wearing—you’re probably within touching distance of something containing or produced by using boron right now. Discover how this amazing element—and the refined, reliable products that U.S. Borax makes from it—enable our modern lives.

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Rio Tinto Borates is a global leader in the supply and science of borates - naturally-occurring minerals containing boron and other elements. Refined borates are essential nutrients for crops. We are 1,000 people serving 500 customers with over 1,700 delivery locations globally. We supply 30% of the world's need for refined borates from our world-class mine in Boron, California, about 100 miles east of Los Angeles.  Learn more about Rio Tinto

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