It is anticipated that the January 2017 proposal for the EU Harmonised Classification of cobalt metal as a carcinogen, mutagen and reproductive toxicant will have significant ramifications for the metal powder processing industries, including Powder Metallurgy, Additive Manufacturing and Metal Injection Moulding.
During a keynote presentation at the EPMA’s European Hard Materials Group (EuroHM) open meeting, held during the 19th Plansee Seminar in Reutte, Austria,at the end of May 2017, Tuulia Svanehav of Sandvik Machining Solutions, Sweden, stated that as a reaction to new available data in 2013, the Cobalt Development Institute (CDI) in conjunction with the Cobalt REACH Consortium (CoRC) took the action to self-classify Co metal as a Category 1B carcinogen via inhalation.
As a consequence, under the rules of the Globally Harmonised System of Classification and Labelling of Chemicals (GHS – a UN initiative 2003), all mixtures containing > 0.1% Co metal carry the same carcinogenicity classification as pure Co.
Svanehav stated that there is a proposal for harmonised classification of cobalt metal by the European Chemicals Agency (ECHA), as shown in Table 1. Because of the obligation to comply with the EU carcinogen and mutagen directive – the parts of proposed harmonised classification that are not in line with the current self-classification of Co metal and WC-Co mixtures – a burden is placed on industry in terms of striving towards closed production processes, where any contact with cobalt containing material is avoided, and seeking possible substitutes.
It is also expected that allowable occupational exposure limits for cobalt in inhalable form, either alone or as a mixture, will decrease substantially in the future. In 2016 a limit of 0.005 mg/m3 of Co was set in the USA, compared with 0.02 mg/m3 in 1993, and in Europe limits are expected to fall even further in the near future (Fig. 1).
Occupational exposure limit for cobalt alone or in hardmetal (from presentation by Tuulia Svanehav, EuroHM Open Meeting, Reutte, 2017)
Under REACH – the European Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals, which entered into force in 2007 – the responsibility for assessing and managing the risks posed by chemicals (substances), such as cobalt, has moved from public authorities to industry through registration and self-classification. As before, industry also provides appropriate safety information (Safety Data Sheets, Labelling) for users of the relevant chemicals.