Boron

Abstract

Abstract Boron is the fifth element of the periodic table and the only electron‐deficient nonmetallic element. Consequently, boron has a high affinity for electronegative atoms such as oxygen and forms strong covalent boron–oxygen bonds in compounds known as borates. Boron is an essential micronutrient in plants and nutritionally important in animals and humans. Boron occurs naturally in all foods; fruits, vegetables, and nuts contain the highest levels. The toxic effects and pharmacokinetics of boron and borates are reviewed. The inorganic boron‐containing materials share many chemical and biological characteristics thought to be due to unique properties of the boron element. This chapter reviews the shared characteristics and the individual inorganic boron‐containing compounds that have a significant use in industry. Some of the more important physical and chemical properties of boron compounds of commercial significance and widespread exposure are listed. Boron has been shown to cause developmental effects and adversely affect male reproduction in laboratory animals. However, there is no clear evidence of male reproductive effects attributable to boron in studies of highly exposed workers or of developmental effects in humans in studies of populations with high exposures to boron.