Japan will oppose including a total ban on dioxins and dibenzofuran in a proposed international treaty aimed at minimizing the release of persistent organic pollutants into the global environment, Japanese government sources said Saturday.

The European Union is poised to propose banning the two chemicals at the fourth session of the U.N.-sponsored Intergovernmental Negotiating Committee scheduled from Monday to Saturday in Bonn, Germany.

"Dioxins and furans are also produced naturally, such as in forest fires, so it is unrealistic to impose total bans on them. If the bans become obligations, the treaty will not be ratified, and we cannot expect developing countries to participate," a Japanese source said.