Thailand’s sandy beaches have long been popular destinations for millions of tourists but concerns are growing that the lotions they use as protection from the tropical sun are harming delicate, slow-growing corals. An order came into force on August 4th banning sun lotions containing substances that could have a harmful effect on coral reefs from the kingdom’s marine national parks.
The banned sunscreens are those containing oxybenzone, octinoxate, 4-methylbenzylidene camphor, which are usually used as UV filters, and butylparaben, that is used as a preservative or as a fragrance. These substances are suspected to be endocrine disruptors and to affect the development of corals, even in small quantities.
Thai authorities said available scientific data showed these chemicals "deteriorate coral reefs, destroy coral larvae, obstruct their reproductive system and cause coral reef bleaching."
While officials have not said how they plan to enforce the new rule, violators would face a fine of up to 100,000 Thai baht (about USD 3,000 or EUR 2,530).
Similar concerns in other countries
Thailand is not the first country to introduce such a ban. On January 1, 2020, the Pacific island of Palau banned the sale and import of sun products containing 11 components deemed toxic to the environment.
In 2018, the State of Hawaii also announced its intention to ban oxybenzone and octinoxate from sun lotions marketed on the islands. This measure has been applied since January 1st, 2021.
Since an initial alert in 2008, several studies have highlighted that certain substances contained in sunscreens could have a negative impact on marine species. For instance, a research published in 2015 showed that oxybenzone could be harmful to coral reefs by accelerating the bleaching of corals and threatening their resilience in front of climate change. 
In France, as part of the “Mission Océans” launched in 2018, the Agency for Food, Environmental and Occupational Health & Safety (ANSES) was charged to carry out an inventory of the chemical substances that are particularly toxic for marine ecosystems and coral reefs while being present in consumer products such as cosmetics, sunscreens or detergents.
However, products claiming to protect the skin from the sun while preserving the oceans are increasingly available on the market. And to help consumers that do not want to harm oceans, US-based Haereticus Environmental Laboratory publishes a list of eco-responsible sunscreens every year.