Canada: solubility key to cobalt substances risk
Sixty day consultation on proposed risk management measures
1 June 2017 / Canada
Canada has concluded that solubility is a crucial factor in the environmental risk posed by cobalt-containing substances.
Cobalt and soluble cobalt compounds are harmful to organisms in the environment and should be subject to regulatory risk management, the government assessment finds.
Specifically, the substances can harm survival, growth and reproduction of water, soil and sediment dwelling organisms.
The assessment says they meet the criteria outlined in paragraph 64(a) of the Canadian Environmental Protection Act 1999 (Cepa 1999), which relates to harmful effects on the environment.
In 2014 Canada published a draft screening assessment of the substances in which it found that all 50 substances met one or more of the paragraph 64 criteria.
But the final screening assessment focuses on the cobalt 'moiety', rather than specific compounds. It considers cobalt in its elemental form, cobalt-containing substances and cobalt released in dissolved, solid or particulate form.
Consequently, it is not limited to consideration of the 50 substances considered in the draft assessment, the authors say.
The conclusion in the final assessment adds cobalt and soluble cobalt compounds to the Cepa 1999 list of toxic substances (Schedule 1).
The main uses of cobalt containing substances are industrial and include:
as intermediates in metallurgical processes;
in non-ferrous metal smelting and refining;
in the production of alloys and carbides; and
Environment and Climate Change Canada and Health Canada have published a risk management approach document outlining their proposed measures.
They have initiated a 60-day public consultation period for the document. Interested parties have until 26 July to submit comments. The final assessment is expected in March 2018.