In the European Union, approximately 80,000 workers are potentially exposed to cobalt and cobalt compounds. The primary work-related exposure route to cobalt is the inhalation of cobalt particles. The exposure to cobalt has been associated with an increased risk of lung and heart diseases. Cobalt metal and several compounds have a harmonised classification according to CLP as Carcinogenic Category 1B, which means they probably cause cancer in humans. Furthermore, allergic skin reaction or allergic asthma can occur after exposure to cobalt metal or to cobalt compounds. Cobalt and many cobalt compounds are also described to damage the fertility or the unborn child.

Where risks occur

Cobalt is present in various applications and products, e.g. as magnets and catalysts. At first, cobalt compounds were industrially produced as heat-resistant pigments and dyes because of their strong blue colours. Today, cobalt is mainly used as a superalloy due to its temperature stability and as a cathode material component for rechargeable batteries. In the production and use of hard-metal and diamond cutting tools, cobalt is applied as bonding material. Exposure can occur in the form of dust and particles during welding, plating, or in surface treatment like passivation. The recycling of batteries, the production of hard-metal and cobalt-containing tools as well as handling of cobalt compound-containing powders are further ways of exposure. The use of cobalt and its compounds is widespread. Relevant sectors of work are the battery industry, metal industry, chemical industry, refinery industry, pigment production, textile leather, wood and paper industry. Applications can be found in the automotive, aerospace and defence sectors, among others.

More about the substance

Cobalt is a naturally occurring odourless, steel-grey, shiny and hard heavy metal. There are different cobalt salts with varying solubility that are industrial relevant, e.g. cobalt sulphate, cobalt dinitrate, cobalt carbonate or cobalt diacetate.

Additionally, cobalt increases the wear resistance, hardness and mechanical strength, e.g. in cutting tools. It is used as a binder in the hard-metal production together with tungsten carbide. Cobalt-containing catalysts are required for the production of clean fuels with low sulphur content. In corrosion protection, cobalt is utilised for materials in warm or hot environments, e. g. engine spaces, brakes and electrical parts in housing.

How symptoms can affect you

The highest potential for occupational exposure to cobalt and cobalt compounds is through inhalation of airborne particles. There is also a risk of dermal or oral exposure to cobalt through hand-to-mouth contact. Exposure to high concentrations of airborne cobalt particles from hard-metal production or diamond polishing can lead to acute respiratory problems and even to pneumonitis (cobalt lung disease or hard-metal lung disease). Cobalt can be absorbed into the bloodstream either through the lungs or the gastrointestinal tract. The long-term effects of prolonged, continuous exposure to cobalt may include skin and lung sensitization, impaired lung function, occupational asthma, pulmonary fibrosis, heart failure and lung cancer.
What you can do

The most effective way to prevent exposure is substitution by safer, cobalt-free alternatives. Where substitution of cobalt and cobalt compounds is not possible and use of cobalt cannot be avoided, measures to reduce exposure must be taken. The most effective way to avoid exposure to cobalt is to develop and use closed systems. Where this is not possible, technical measures such as effective local exhaust ventilation, good ventilation of the workplace should be implemented to ensure that exposure is minimised as much as technically possible. Implement regular exposure measurements to check if your protective measures in place are effective or whether further actions need to be taken. Biological monitoring can support exposure measurements, if applicable in the national legislation.

Workers need to be aware of the effects of exposure and should be encouraged to report early symptoms of respiratory problems or skin allergies. Involving an occupational physician is recommended. Workers should be trained on the control measures necessary for working safely with cobalt to prevent exposure) Additionally, all workers should be instructed to wash their hands properly before taking a break or entering another area, and to wash themselves and change their clothes at the end of each shift. Ensure that workers have adequate personal protective equipment, such as protective clothing and gloves, if necessary. Personal protective equipment should only be used as a last resort, after the possible technical measures have been considered.

References: CLP, ECHA (RAC), Cobalt Institute