GENEVA (AP) — A new global treaty could eliminate within three decades the commercial use of mercury in everything from batteries, paints and skin-lightening creams to utility plants and small-scale gold mining, the head of the U.N.’s environment agency said Thursday.

Achim Steiner, the executive director of the U.N. Environment Program, calls the Minamata Convention on Mercury a major gamechanger for a naturally occurring element that tends to accumulate in fish and work up the food chain.

The first new global convention on environment and health for nearly a decade was formally adopted as international law to little notice worldwide at a gathering of more than 90 nations in Japan last week.

Steiner says the treaty, which still requires ratification by 50 of the nations which signed the treaty in Japan, could accomplish its aim of curbing harmful emissions of mercury anywhere from about 2025 to 2050. It would do that through banning new mercury mines and phasing out existing ones, imposing control measures on air emissions and regulating artisanal or small-scale gold mining.

“Essentially, what we have managed to do is to persuade the international community to send a very clear signal — the use of mercury in industrial processes, in cosmetics, in medical equipment, is essentially over,” Steiner told reporters in Geneva. “It doesn’t mean that all mercury will disappear tomorrow.”

But nations with artisanal and small-scale gold mining operations, one of the biggest sources of mercury releases, will only be required to draw up national plans within three years of the treaty entering force and then to reduce and — if possible — eliminate the use of mercury in such operations.