In a statement in July 2019 to the WTO’s Committee on Technical Barriers to Trade, the US said that it was “disappointed” that the EC was making the move without consulting WTO members.

EU draft proposals would classify titanium dioxide in powder form as a potential carcinogen, or category 2 carcinogen. This would mean that any product containing it would need to carry a warning label.

Cobalt metal is also facing a change in classification, and could be classed as a category 1B substance, or “presumed carcinogen.” This would impose even stronger restrictions.

The US first raised an objection to the labelling plans in March 2019, saying that the new rules could be “unnecessarily disruptive to billions of dollars in US-EU trade.”

The EC responded to this first US statement by saying that the classification would only have a limited effect on downstream users.

The proposal also faced opposition from other WTO members. In July, the Russian delegation to the WTO claimed that it could disrupt the trade in stainless steel and nickel, which can contain small amounts of cobalt.

Australia, Mexico and the Philippines have all raised concerns as well.

The EC’s proposal on titanium dioxide tries to find a middle ground between an opinion from the European Chemical Agency that called for all forms of titanium dioxide to be classified as potential carcinogens, and pressure from industry lobbyists opposing such a classification in any form.

In 2016, the French government triggered an EU inquiry into titanium dioxide use after research showed increased occurrence of pre-cancerous lesions in exposed rats.

But industry sources have cast doubt on the significance of those findings, saying specifically that such outcomes have not been observed in humans working with titanium dioxide, nor in other animals which have respiratory systems closer to those of humans.