Palau, which lies in the western Pacific about halfway between Australia and Japan, is regarded as one of the world's best diving destinations, but the government is concerned its popularity is coming at a cost. A spokesman for President Tommy Remengesau said there was scientific evidence that the chemicals found in most sunscreens are toxic to corals, even in minute doses.

He said Palau's dive sites typically hosted about four boats an hour packed with tourists, leading to concerns a build-up of chemicals could see the reefs reach tipping point. "On any given day that equates to gallons of sunscreen going into the ocean in Palau's famous dive spots and snorkelling places," he said. "We're just looking at what we can do to prevent pollution getting into the environment."

The government has passed a law banning "reef-toxic" sunscreen from January 1, 2020. Anyone importing or selling banned sunscreen from that date faces a fine of 1,000 US Dollar, while tourists who bring it into the country will have it confiscated.

The US state of Hawaii announced a ban on reef toxic sunscreens in May this year, but it does not come into force until 2021, a year after Palau's.

ak/ey (AFP)