A Spanish coal company has said it will stop supplying imported Chinese coal after US regulators imposed a ban on the fuel due to health risks linked to the material.

In a statement on its website on Monday, Spain’s First Coal said the ban on its product had been imposed in response to an investigation by the US Environmental Protection Agency (EPA).

It said the EPA’s investigation found that First Coal had improperly supplied a chemical known as “Cyanotane”, which was linked to elevated risks for respiratory and cardiovascular health.

China’s state-run Xinhua news agency said the agency had “found insufficient evidence to prove the safety of the substance”.

Chinese authorities have also accused First Coal of misleading the US about the safety and environmental impact of its products, in a dispute that has dragged on for years.

First Coal has said its products are “not harmful”.

The EPA has said the product does contain a small amount of cyanotane, but First Coal disputes that.

“There is no such safety issue,” First Coal chief executive Francisco Aparicio said in the statement.

China banned imports of coal from Spain in 2011 amid concerns about the health risks of the material and the fact that the US banned imports in 2013.

The US also banned imports from other countries in 2013 after a similar case involving Chinese imports.

In response to a request for comment from Engadgets, First Coal declined to comment.

But the Spanish government has previously said it wants to boost export opportunities for Spanish coal, which accounts for a third of the country’s exports.