Environmentalists are angry that a Russian rocket stage potentially carrying highly toxic chemicals is expected to splash down this weekend in a biodiversity hotspot in the Canadian Arctic.

"The idea of dropping a missile full of toxic chemicals in the Arctic waters off Baffin Island is just as preposterous as drilling for oil there," Greenpeace Arctic campaigner Alex Speers-Roesch said Tuesday.

"Dumping these chemicals from a ship would be a clear violation of international and Canadian law, and it is no more acceptable when it is dumped from the air."

A spokesman from the Canadian government was not immediately available.

"Dumping these chemicals from a ship would be a clear violation of international and Canadian law, and it is no more acceptable when it is dumped from the air."

An international aviation authority has issued a notice warning that debris from a Russian rocket launch is slated to fall Saturday into Baffin Bay. That's outside Canada's territorial waters but inside an economic zone the country partially controls.

The space debris is a stage from a rocket set off under Russia's Rokot program, a for-profit service that launches commercial satellites, said Michael Byers, a professor of international law and an Arctic expert at the University of British Columbia.

Byers said Russia is following the rules by informing aviation authorities of the launch and the splashdown. The stage is falling over a remote stretch of water between Greenland and the southern tip of Ellesmere Island.

He notes Rokot uses repurposed Cold-War-era intercontinental ballistic missiles to launch satellites. Those missiles, the SS-19, use hydrazine for fuel.

Hydrazine is known to be extremely toxic — so toxic that technicians working with it have to use pressurized hazmat suits, Byers said.

"The United States has very deliberately moved away from it because of the health and environment risk."