Hawaii Gov. David Ige on Tuesday signed legislation that will ban the sale of sunscreens containing two chemicals believed to harm coral reefs.
The move makes Hawaii the first U.S. state to enact a ban on oxybenzone and octinoxate.
"This is just one small step toward protecting and restoring the resiliency of Hawaii's reefs," Ige said at a signing ceremony for the bill, which takes effect in 2021.
Ige said the state would also need to continue other efforts to protect coral, including fighting invasive species, pollution from land runoff and climate change.
Sunscreen containing oxybenzone and octinoxate will only be available to those with a prescription from a physician. Others will have to buy sunscreens without these chemicals or bring their own sunscreen with them to Hawaii.
Scientists have found the two substances can be toxic to coral reefs, which are a vital part of the ocean ecosystem and a popular draw for tourists.
State Sen. Roz Baker, who represents south and west Maui, said the bill has enormous significance because coral is such a fundamental part of a larger ecosystem important to the health of the planet.
Critics say there aren't enough independent scientific studies supporting the assertion that the chemicals harm coral reefs.
The group Retail Merchants of Hawaii has said it's concerned the ban will discourage people from buying sunscreen at brick and mortar stores.
But state Rep. Chris Lee, who represents the Honolulu suburbs of Kailua and Waimanalo, said the law is a necessary step to help Hawaii pass on its reefs, ocean, tourism industry and way of life to the next generation.
Leaders need to act quickly to save what coral world has left, he said.
"We know the tide is against us. We've got limited amount of time," Lee said.