Human Health 

Understanding cobalt’s role in health: Balancing essentiality and safety

Cobalt is essential to human health as a core component of Vitamin B12, which has many important functions, such as supporting blood cell formation and brain function.

Naturally present in the environment, cobalt enters our diet through plants, meat and dairy, meaning humans are exposed to background levels of cobalt on a regular basis. Humans need cobalt in order to stay healthy, however, as with many substances, an excessive amount can be harmful to human health.

It also plays a critical role in medical applications, from historical treatments for anaemia, use in medical devices such as hip implants and radiotherapy (cobalt-60) for cancer care.

The majority of people are highly unlikely to naturally encounter cobalt in large enough amounts for it to be dangerous, but people working in manufacturing facilities where cobalt is produced and used could be at risk without mitigation measures.

The cobalt industry recognises the need to manage workplace exposures to cobalt and has played a leading role in generating the scientific data required to understand and manage the risks associated with cobalt exposure.

Human health data generation and read-across approaches

Given the extensive nature of the cobalt substance portfolio –comprising over 20 different substances – read-across approaches have been used to streamline data generation. This method involves predicting the biological effects of one substance (the target substance) by using existing data from another, similar substance (the source substance). The approach is based on the hypothesis that the substances share a common “toxic unit,” such as a similar chemical structure, which allows for scientifically justified extrapolation.

In the metals sector, read-across approaches are often based on the hypothesis that the shared “toxic unit” among substances is the metal ion itself, which is responsible for the observed biological effects.

In the case of cobalt, read-across strategies are grounded in this principle and further reinforced by additional well-established characteristics specific to cobalt substances.

Cobalt Institute has developed tailored read-across strategies to support the hazard assessment and regulatory compliance of cobalt substances, particularly under frameworks such as the EU REACH regulation. These strategies are aligned with the European Chemicals Agency’s (ECHA) Read-Across Assessment Framework (RAAF) and are specifically adapted to the unique physicochemical and toxicological profiles of the registered cobalt substances.

Given the route-specific toxicological properties of cobalt substances, the Institute has established several read-across approaches based on exposure route, substance characteristics—such as the bioavailability of the cobalt ion—and supporting toxicological data.

For detailed information on the inhalation read-across approach, please refer to the following publications:

For information on the oral read-across approach, please refer to the following publication:

Protecting people at work

The cobalt industry is committed to continuously improving working conditions in environments where cobalt and its compounds are used. Cobalt is manufactured and utilised in various forms in the workplace, such as plating, formulating chemicals, and producing alloys.

Workers may encounter cobalt in the form of chunks, pellets, powders, or cobalt salts. Cobalt substances are generally used in highly controlled industrial settings where exposure risks are minimised through risk management measures and automation.

Exposures to cobalt in the workplace have continuously and significantly decreased over the past decades. Current industry practices should guarantee that workers are not exposed to cobalt at a level that is considered harmful.

Exposure to each cobalt substance is described and documented in REACH and other global regulations. The cobalt industry abides by these rules.

To further minimise cobalt exposure, several safety measures are put into practice:

Engineering Controls:

The installation of specialised equipment and systems, such as ventilation improvements and automation of processes, helps reduce cobalt emissions.

Personal Protective Equipment (PPE):

Workers are provided with appropriate PPE to protect against inhalation or direct exposure.

Low-Emission Physical Forms:

Cobalt can also be used in physical forms that have lower emission potential, such as wetted or liquid forms, further reducing exposure.

Ongoing research, improved workplace practices, and regulatory measures ensure that cobalt is handled in a responsible and safe manner across industries.

General population

The general population is exposed to both man-made and natural sources of cobalt through air, water and diet.

The greatest exposure to cobalt for the general population is through food in their diet. Cobalt is essential to human life as part of Vitamin B12, in which the reference nutrient intake (RNI) value for adults is approximately 1.5 µg of Vitamin B12/day (COMA 1991).

In addition, as inorganic cobalt (not in the form of Vitamin B12) is essential for many plants and ruminant animals, it is often found in a variety of food sources such as meat, dairy products, fish, green leafy vegetables, fresh cereals and nuts. On average, the daily exposure estimation of adults to inorganic cobalt is 12 µg cobalt from food sources (excluding supplements) (UK Expert Group, 2003). The European Food Safety Authority (EFSA) has suggested an acceptable safe amount of cobalt of 120 µg Co/day while the UK Expert Group on Vitamins and Minerals has stated that up to 1400 µg Co/day (in a 60 kg adult) was unlikely to lead to adverse health effects (UK Expert Group, 2003).

Committee on Medical Aspects (COMA) of Food and Nutrition Policy. 1991. Report on Health and Social Subjects No.41, 1991. Dietary Reference values for Food Energy and Nutrients for the United Kingdom. HMSO, London.

Expert Group on Vitamins and Minerals. Safe upper levels for vitamins and minerals. London: Food Standards Agency. 2003.

European Food Safety Authority. Scientific Opinion on safety and efficacy of cobalt compounds (E3) as feed additives for all animal species: Cobaltous acetate tetrahydrate, basic cobaltous carbonate monohydrate and cobaltous sulphate heptahydrate, based on a dossier submitted by TREAC EEIG1. EFSA J 10(7):1-27. 2012.