Recently in Changchun Customs District, totally 4,682 tons of substandard import coal was returned to Russia from the Hunchun port by railway. The return was conducted under the control of Hunchun Customs House after these Russian coal was identified to be excessive in fluorine content.

With excessive fluorine, burning coal will give off some toxic gas to harm human health and eco-environment. Thus, China has strict regulation on the fluorine content in commercial coal, with current standard not more than 200-microgram fluorine per gram of coal.