Boron is a compound that occurs in nature. It is often found combined with other substances to form compounds called borates. Common borate compounds include boric acid, salts of borates, and boron oxide. Several companies in the United States produce most of the world's borates by processing boron compounds. Borates are used mostly to produce glass. They are also used in fire retardants, leather tanning industries, cosmetics, photographic materials, soaps and cleaners, and for high-energy fuel. Some pesticides used for cockroach control and some wood preservatives also contain borates.

Fate & Transport

Boron is released to the environment from natural sources such as oceans, volcanoes, and geothermal steam. Boron is also released from industries that use it. No information is available on how long boron remains in air, water, or soil. Boron does not appear to accumulate in fish or other organisms in water. Boron accumulates in plants and is found in foods, mainly fruits and vegetables.

Exposure Pathways

In air, water, and food at low levels

Drinking water that contains it from areas where boron is found naturally at high levels in the earth

Eating foods containing high levels

Working in borax mining and refining plants and at sites where boric acid is manufactured

Using consumer products that contain it, such as cosmetics and laundry products.

Health Effects

There is little information on the health effects of long-term exposure to boron. Most of the studies are on short-term exposures. Breathing moderate levels of boron can result in irritation of the nose, throat, and eyes. Reproductive effects, such as low sperm count, were seen in men exposed to boron over the long-term. Animal studies have shown effects on the lungs from breathing high levels of boron.

Ingesting large amounts of boron over short periods of time can harm the stomach, intestines, liver, kidney, and brain. Animal studies of ingestion of boron found effects on the testes in male animals. Birth defects were also seen in the offspring of female animals exposed during pregnancy. We don't know what the effects are in people from skin contact with boron. Animal studies have found skin irritation when boron was applied directly to the skin.

The Department of Health and Human Services, the International Agency for Research on Cancer, and the Environmental Protection Agency (EPA) have not classified boron as to its human carcinogenicity. One animal study found no evidence of cancer after lifetime exposure to boric acid in food. No human studies are available.

Information excerpted from:

Toxicological Profile for Boron 1992

Agency for Toxic Substances and Disease Registry
U.S. Dept. of Health and Human Services