(CNN) -- Some sun protection may come at a steep price for the ocean's coral reefs. Now, a Florida state senator wants to ban some sunscreens entirely for the potential harm they cause marine life.
Sen. Linda Stewart's proposed bill would require a prescription to use sunscreens with oxybenzone and octinoxate, two chemicals found in most sunscreens that effectively protect against UV radiation but, researchers suggest, can also cause coral bleaching and eventually kill reefs.
Under the bill, their sale would be banned without a prescription."Reef-safe" sunscreens that leave out those ingredients in lieu of others, like FDA-approved zinc oxide, would take their place on store shelves.
Stewart told CNN she modeled her bill after similar ones passed in Key West and Hawaii. Those banned the sale of all sunscreens with the two chemicals to protect nearby reefs, essential to the islands' tourism economy and marine biodiversity. The measures won't go into effect until January 2021.
Reefs are important
If reefs continue to die, global coastlines would take a serious hit.
Coral reefs are natural protection for coastlines, absorbing 97% of a wave's energy to prevent erosion and potential property damage incurred from currents and storms, according to the National Oceanic and Atmospheric Administration.
They're also home to 25% of all marine life, serving as tropical rainforests that protect the ocean's biodiversity.
But they're under constant attack, and chemicals in sunscreen are hardly corals' only foe. Climbing ocean temperatures and pollution have killed nearly 30% of the world's reefs, causing heat stress and mass bleaching events, according to NOAA.
For best sun protection practices, NOAA recommends opting for "reef-safe" sunscreens and, better yet, covering up. Staying under an umbrella, wearing UV sunglasses and long-sleeve shirts and leggings protects skin even better than sunscreen does, the agency said.
Opponents say the bill could increase skin cancer
Dermatologists have already taken issue with the Hawaii and Key West bans out of fear they'll cause skin cancer rates to rise or create a stigma around sun protection.
The American Academy of Dermatology assured that sunscreen remains a safe, effective form of sun protection despite the bill and any claims that they were toxic to human health were "unproven" in a statement released months before Hawaii's bill passed in 2018.
Skin cancer is still the most common form of cancer in the US, and it's steadily risen over the last several years, from about 66,000 in 2009 to more than 82,000 in 2016, according to the US Centers for Disease Control and Prevention.
Florida has the second-highest rate of melanoma in the country, the CDC said, largely due to its proximity to the equator, where UV rays are strongest, and year-round, beach friendly weather.
If approved, Stewart's ban will enter effect in July 2020. But she said she's already received pushback from fellow legislators and doctors -- she lives in the Sunshine State, after all.
"The reason for this bill is just to make sure that is discourages the use of those two chemicals," she said. "I'm not doing this so everyone gets skin cancer. There are so many other sunscreens out there that are reef-safe."
But there's no agreed-upon definition for what "reef-safe" means, according to Consumer Reports, so manufacturers aren't made to prove their impact on marine life.
Chemicals absorbed into skin -- for better or worse
Even though the Food and Drug Administration allows the ingredients in sunscreen, there's insufficient evidence to show how the chemicals affect the human body beyond UV protection.
"If it's hurting ocean life, it seems to me it might have some other effect on the human body," Stewart said.
A May study in the Journal of the American Medical Association found that four active ingredients, including oxybenzone, are absorbed through the skin. Whether or not they're unsafe for the human body, though, requires more research.
Only two sunscreen ingredients are "generally recognized as safe and effective" for people by the FDA: Zinc oxide and titanium dioxide.
The agency has requested data from manufacturers for 12 active ingredients, including the two Stewart's bill would ban, to determine their health effects and inform new sunscreen regulations.