The element beryllium is a grey metal that is stronger than steel and lighter than aluminum. Its physical properties of great strength-to-weight, high melting point, excellent thermal stability and conductivity, reflectivity, and transparency to X-rays make it an essential material in the aerospace, telecommunications, information technology, defense, medical, and nuclear industries. Beryllium is classified as a strategic and critical material by the U.S. Department of Defense.
Beryllium is used industrially in three forms: as a pure metal, as beryllium oxide, and most commonly, as an alloy with copper, aluminum, magnesium, or nickel. Beryllium oxide (called beryllia) is known for its high heat capacity and is an important component of certain sensitive electronic equipment. Beryllium alloys are classified into two types: high beryllium content (up to 30% beryllium) and low beryllium content (2 - 3% beryllium). Copper-beryllium alloy is commonly used to make bushings, bearings, and springs. Beryllium is also found as a trace metal in slags and fly ash.
OSHA's Beryllium Webpage
U.S. Department of Labor Proposes to Revise Beryllium Standard for General Industry Dec 2018
Protecting Workers' from Exposure to Beryllium and Beryllium Compounds: Final Rule Overview.
Medical Surveillance for Beryllium‑Exposed Workers
OSHA’s Beryllium Rule: Stakeholder Participation and Changes to the Proposed Rule (2017)
Occupational Exposure To Beryllium And Beryllium Compounds 09 17