In response to a request by the European Commission, the European Chemicals Agency (ECHA) has submitted a REACH restriction dossier concerning five cobalt salts and their hydrates.
The five cobalt salts selected are listed in the table:
They are produced and widely used to manufacture chemicals, catalysts, batteries, feed grade materials and biogas. The salts are also used for surface treatments and in fermentation processes.
Around 30 000 tons of the salts are used each year in the EU. They are used in the largest amounts as transported isolated intermediates to manufacture other chemicals. These would still be subject to the proposed restriction.
Over the last decade, the volumes placed on the EU market have doubled, and the rise in demand is likely to continue, as there is expected to be an increased need for rechargeable batteries, biotechnology and health applications.
It is estimated that around 35 000 workers are exposed to the cobalt salts at around 20 000 industrial sites within the EU. The element cobalt is a heavy metal and also used as such as solid metal or metal powder.
The cobalt salts are carcinogens and reprotoxicants, as well as skin and respiratory sensitizers. They are also aquatic toxicants. Many years ago I co-authored a review of the carcinogenicity of cobalt and was later member of the IARC Working Group making the first assessment of cobalt in 1991 (IARC monograph 52).
ECHA has found that the risks arising from the manufacture and use of the cobalt salts are not adequately controlled, and ECHA proposes to implement a reference exposure value for workers exposures. There were no significant consumer uses or exposures to be regulated.
The proposal assesses the following reference values to be communicated to the workers by an extended Safety Data Sheet:
- 10 µg Co/m3;
- 1 µg Co/m3;
- 0.1 µg Co/m3; and
- 0.01 µg Co/m3.
The highest value is the present occupational (TWA) limit. Final deadline for comments on Annex XV (restriction) report is June 19, 2019.
The overall aim is to decrease the excess cancer risk levels and the number of cancer cases arising from occupational exposure to the cobalt salts through inhalation.
However, this proposal is very weak and based on information provided by and opinions of the involved industry organization. Cobalt salts are non-volatile and many are water soluble. The concentrations in the workplace air will normally be relative low and will consist of dusts and aerosols. In practice, the main hazards and risks will rather be contact with the skin and mucous membranes, which are not restricted by this proposal.
Intended inhalative exposure of workers to the very hazardous cobalt salts at workplaces should not be allowed at all. All manufacturing processes should be completely closed, and when opened to get materials in and out, the workers should have full protection, as if they was handling asbestos or PCB.