Beryllium (Be), formerly (until 1957) glucinium, chemical element, the lightest member of the alkaline-earth metals of Group 2 (IIa) of the periodic table, used in metallurgy as a hardening agent and in many outer space and nuclear applications. Beryllium (2+) Please visit the Beryllium element page for information specific to the chemical element of the periodic table.
Beryllium
Overview
Visit OSHA's Beryllium Rulemaking page for information on the final rule and related rulemaking.
- NEWEnforcement for the Beryllium Standards in Construction and Maritime. OSHA, (September 2020).
- Protecting Workers' from Exposure to Beryllium and Beryllium Compounds: Final Rule Overview. OSHA Fact Sheet (Publication 3821), (2017).
- Medical Surveillance for Beryllium-Exposed Workers. OSHA Fact Sheet (Publication 3822), (2017).
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. In 2014, the U.S. produced 270 metric tons of beryllium domestically and imported 68 metric tons, increases from 2013 of 15% and 19% respectively. Government stockpile release is another source of beryllium. Bertrandite (<1% beryllium) is the principal mineral mined for beryllium in the U.S. while beryl (4% beryllium) is the principal mineral mined for beryllium in the rest of the world.
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.
This page offers guidance that may be useful to workers and employers across a number of industries.
Why is beryllium a hazard to workers?
Workers in industries where beryllium is present may be exposed to beryllium by inhaling or contacting beryllium in the air or on surfaces. Inhaling or contacting beryllium can cause an immune response that results in an individual becoming sensitized to beryllium. Individuals with beryllium sensitization are at risk for developing a debilitating disease of the lungs called chronic beryllium disease (CBD) if they inhale airborne beryllium after becoming sensitized. Beryllium-exposed workers may also develop other adverse health effects such as acute beryllium disease, and lung cancer. See the Health Effects section in the preamble of the Beryllium Final Rule for more information.
What is OSHA doing to protect workers from exposure to beryllium?
OSHA’s final rule for beryllium requires employers in general industry, construction, and shipyards to implement protective measures for workers who are exposed to beryllium. For more information on the compliance dates and requirements of the beryllium standards for general industry, construction, and shipyards see OSHA’s final rulemaking webpage.
Who is exposed to beryllium in the workplace?
OSHA estimates that approximately 62,000 workers are potentially exposed to beryllium in approximately 7,300 establishments in the United States. While the highest exposures occur in the workplace, family members of workers who work with beryllium also have potential exposure from contaminated work clothing and vehicles. Based on OSHA Integrated Management Information System and industry exposure data, beryllium workers in primary beryllium manufacturing and alloy production, and recycling have the highest average exposures to beryllium. Occupations with potential exposure to beryllium include:
- Primary Beryllium Production Workers
- Workers Processing Beryllium Metal/Alloys/Composites
- Foundry Workers
- Furnace Tenders
- Machine Operators
- Machinists
- Metal Fabricators
- Welders
- Dental Technicians
- Secondary smelting and refining (recycling electronic and computer parts, metals)
- Abrasive Blasters (slags)
Certain types of slags (coal, copper) used in abrasive blasting operations may contain trace amounts of beryllium (<0.1 % by weight). Due to the high dust conditions inherent in abrasive blasting operations, workers involved in these activities may be exposed to dangerous levels of beryllium.
Where is beryllium used?
End products1 containing beryllium and beryllium compounds are used in many industries including:
- Aerospace (aircraft braking systems, engines, satellites, space telescope)
- Automotive (anti- lock brake systems, ignitions)
- Ceramic manufacturing (rocket covers, semiconductor chips)
- Defense (components for nuclear weapons, missile parts, guidance systems, optical systems)
- Dental labs (alloys in crowns, bridges, and dental plates)
- Electronics (x- rays, computer parts, telecommunication parts, automotive parts)
- Energy (microwave devices, relays)
- Medicine (laser devices, electro-medical devices, X-ray windows)
- Nuclear energy (heat shields, reactors)
- Sporting goods (golf clubs, bicycles)
- Telecommunications (optical systems, wireless base stations)
Health Effects
Exposure to beryllium via inhalation of airborne beryllium or skin contact with beryllium-containing dust, fume, mist, or solutions can cause health effects.
Exposure Evaluation and Controls
These resources provide information on exposure limits and analytical methods used to evaluate workers’ beryllium exposure.
OSHA Standards and Enforcement
Beryllium is addressed in OSHA standards for general industry, maritime, and construction.
General Resources
This section provides useful resources and guidance materials for both employers and employees on Beryllium.
- Protecting Workers' from Exposure to Beryllium and Beryllium Compounds: Final Rule Overview. OSHA Fact Sheet (Publication 3821), (2017).
- Medical Surveillance for Beryllium-Exposed Workers. OSHA Fact Sheet (Publication 3822), (2017).
1This list describes end uses of products containing beryllium, not sources of beryllium exposure. Exposures to beryllium occur in the processing of beryllium-containing materials to produce these end products, not in the use of these end products in their finished form.
Beryllium has an atomic number 4 and is the first element of the 2nd group of the periodic table. It is classified as an alkaline earth metal. Beryllium is a comparatively rare element. It can be found in many gemstones. It has an atomic mass of 9.012 u and is represented by Be.
Beryllium is located in the S-block in the 2nd period. Thus its outermost electron is located in the s orbital. Beryllium has an electronic configuration of 1s2 2s2.
Beryllium is grey-white in color. It is relatively less dense and is, therefore, a lightweight metal. It has a hexagonal close-packed crystal structure. As all the electrons are paired it is diamagnetic (repels magnetic field lines).
Beryllium has a metallic radius of 111 pm.
All alkaline earth metals have low ionization enthalpies as they are electropositive. However, beryllium has the least radius among all the group two elements so it has comparatively high ionization enthalpy.
Beryllium does not impart any color to the flame during the flame test as its electrons are too strongly bound. Thus the electrons don’t get excited to higher levels even due to the flame, and thus no color can be seen. Beryllium has a high thermal conductivity.
Beryllium is both a common participant and a product in many nuclear reactions. It is present in the core of stars and it undergoes nuclear fusion to produce heavier elements. Beryllium was used in the discovery of the atomic structure and the discovery of the neutron by James Chadwick.
Chemical Properties of Beryllium
Beryllium is comparatively less reactive due to its completely filled outer s orbital. The beryllium atom is also small in size. However, it does participate in the following reactions.
With air
Powdered beryllium reacts with air to form BeO (beryllium oxide, amphoteric oxide) and Be3N2(beryllium intrude). Powdered beryllium burns in the air when ignited to form these compounds.
2Be + O2 -> 2BeO
3Be + N2 -> Be3N2
When beryllium reacts with oxygen or water, a very thin layer of beryllium oxide forms on the surface. This serves as a protective layer and the layers beneath this oxide do not react with the oxygen.
With halogens
All alkaline earth metals, including beryllium, react with halogen ( F, Cl, Br, I) at high temperatures thus resulting in the formation of metallic halides.
Be + X2 -> BeX2 where X=F, Cl, Br, I
With acids
Beryllium is located in group 2 and it’s an alkaline earth metal. Due to its electropositive nature, it is of the alkaline property. Thus beryllium reacts with acids liberating dihydrogen gas.
Be + 2HCl → BeCl2 + H2
Reducing agent
Alkaline earth metals are electropositive in nature and thus can donate electrons acting as a good reducing agent.
But beryllium has a small radius and thus can’t donate electrons easily. So it has a less negative reduction potential (more negative reduction potential means more reducing power). However, due to the small size of Be2+ ion, it is stabilized easily by hydration energy. This gives beryllium it’s reducing nature as after donating electrons the ion is stabilized.
With hydrogen
Beryllium does not react with hydrogen on heating. But BeH2( beryllium hydride) can be produced in the following alternative method.
2BeCl2 + LiAlH4 → 2BeH2 + LiCl + AlCl2
Thus beryllium chloride is used. LiAlH4 is a very strong reducing agent and donates hydrogen easily.
Alternative methods to produce beryllium hydrides
Beryllium fluoride is produced from (NH4)2BeF4 by thermal decomposition.
Be(OH)2 + 2 (NH4)HF2 → (NH4)2BeF4 + 2 H2O
(NH4)2BeF4 → BeF2 + 2 NH3 + 2 HF
Beryllium chloride can be produced from beryllium oxide.
BeO+ C+ Cl2 →2 BeCl2 + CO
In liquid ammonia
All alkaline earth metals including beryllium dissolve in liquid ammonia. Solutions of ammoniated ions are formed which are deep blue-black in color.
With concentrated nitric acid
Beryllium resists the attack of concentrated nitric acid
Compounds of beryllium
The main oxidation state of beryllium is +2. Due to its small size, it forms predominantly covalent compounds.
Beryllium oxide forms on the reaction of oxygen with beryllium. It is amphoteric. It is quite stable to heat.
Beryllium hydroxide is amphoteric in nature.
Be(OH)2 + 2OH– → [Be(OH)4]2-
Beryllate ion is formed when beryllium hydroxide reacts with a base as shown above.
On reacting with acids
Be(OH)2 + 2HCl + 2H2O→[Be(OH)4]Cl2
Beryllium carbonate decomposes to give beryllium oxide and carbon dioxide. It is unstable at room temperature in the free atmosphere. It has to be stored in a CO2 rich atmosphere. Thus by Le Chatelier principle, the reaction shifts more to the left side.
BeCO3 = BeO + CO2
Beryllium halides are covalent and soluble in an organic solvent. Beryllium chloride has different structures in different phases. In the vapor state BeCl2 forms a chloro-bridged dimer which dissociates into the linear monomeric structure at high temperatures. In the solid-state Beryllium chloride ( BeCl2) has a chain structure.
Beryllium nitrate decomposes on heating to give beryllium oxide.
2Be(NO3)2 → 2BeO + 4NO2 + O2
Anomalous properties of Beryllium
Beryllium shows an anomalous behavior as
compared to the other members of Group 2.
Due to the small size of beryllium, it has higher ionization enthalpy. It also forms more covalent compounds.
The oxides and hydroxides of beryllium,
are amphoteric in nature while the oxides and hydroxides of the other members in the group are basic.
The maximum coordination number that beryllium can exhibit is only 4 (like (BeF4)2-) as it has only 4 orbitals in its valence shell, unlike the other members of the group who can express a coordination number of six as they have d-orbitals.
Many properties of beryllium are similar to aluminum and thus these two exhibits a diagonal relationship. They both have a similar ionic radius and charge/radius ratio. Both form protective oxide layers on their surface. Their chlorides are strong Lewis acids and are used as Friedel Craft catalysts.
Beryllium Atomic Structure
Uses of Beryllium
Beryllium Atom
- Beryllium was used to discover neutrons by James Chadwick. Beryllium was bombarded with alpha particles emitted from polonium which gave off a penetrating, electrically neutral radiation. It was proved that these emissions consisted of a particle with a mass similar to that of a proton. This was named as a neutron.
- Beryllium is popularly used as an alloying agent. Copper-beryllium alloys are used to make high strength springs, welding electrodes, electrical contacts in phones, etc.
- Metallic beryllium is quite transparent to X-rays, so thin Be-foil is used for making windows in X-ray tubes.
- Beryllium is a lightweight metal and also has a very high melting point. Thus it finds use in aircraft, satellites, space crafts, etc.
- Beryllium is used in nuclear reactors as a moderator and neutron reflectors. It has high thermal conductivity and is transparent to most forms of radiation.
- Beryllium is non-sparking, temperature-resistant metal and is thus used to make tools and instruments in the oil and automotive industry.
- Other uses include windshield frame, support beams, brakes, etc. where lightweight but stiff material is required.