Oxybenzone (benzophenone-3)1 is one of the most common ingredients found in sunscreen products. Its primary function is to prevent your skin from absorbing ultraviolet (UV) light. Since the chemical is cost effective and increases the sunblock protection in a sunscreen product, it can be found in nearly 3,500 brands of sunscreen worldwide.2
If you reapply the product every two hours as directed, an average day at the beach may mean you are exposed to 2 to 4 ounces of a product containing chemicals known to disrupt human hormones.3 Studies have also suggested oxybenzone is a hormone disruptor in marine creatures.4
Although much media attention is focused on oxybenzone, other chemicals in sunscreens trigger damage to human health and the environment. These include octinoxate, which has demonstrated hormone disruption in animals and behavioral alterations, homosalate, which is unstable and breaks down in the sun, and avobenzone that may damage sperm.5
As you swim, sunscreen is released into the water, necessitating reapplication. However, this release also dumps up to 14,000 metric tons of product into coral reef areas each year.6 Much of the sunscreen contains oxybenzone that may damage marine life at levels as low as 62 drops per trillion, or the equivalent of one drop in 6.5 Olympic-sized swimming pools of water.7
In an effort to protect the coral reefs surrounding the Hawaiian Islands, democratic state senator for Hawaii’s 19th District, Will Espero, has introduced legislation that would ban the use of sunscreen that contains oxybenzone on the Islands in an effort to protect the surrounding coral reefs.8
How Sunscreen Works
Sunscreen use has risen dramatically in the past decade as the medical community began warning against sunburn and sun exposure to reduce the risk of skin cancer.9 This created a growing billion-dollar sunscreen industry. According to industry analysts, the global market for sun care products is projected to hit $11.1 billion by 2020.10
Sunscreen products work one of two ways to protect your skin from UV rays from the sun. The first is a mechanical barrier used by mineral products that create a physical barrier to protect your skin. The two most common are titanium dioxide and zinc oxide. In the past, these products were a thick white paste. However, in response to consumer demand for more visually pleasing products, manufacturers have turned to using nanoparticles of the same chemicals.
While much of the danger to humans is inhalation of these nanoparticles,11 which is why spray-on products are best avoided, these nanoparticles have also been shown to cause ecological and aquatic damage after being released into the environment.12 The second form of sunscreen product, chemical filters, hold greater potential for harm to the environment and human health.
A chemical filter works by undergoing a chemical reaction after it is absorbed into your skin,13 in the presence of UV light and heat. This means it gradually loses protective properties and requires reapplication every two to three hours.14 These sunscreens also include other ingredients meant to increase the penetration of the chemicals into your skin, called "penetration enhancers."15
The Environmental Working Group (EWG) reports that oxybenzone, one of the most "worrisome" chemicals found in sunscreen, is in 65 percent of sunscreen products on the market.16 Laboratory testing has demonstrated this chemical causes allergic skin reactions, and has weak estrogenic and powerful antiandrogenic effects in the body. A Centers for Disease Control and Prevention (CDC) report found oxybenzone in more than 96 percent of people living in the U.S.17
Data collected from adolescents reveal young boys with higher levels of oxybenzone had lower levels of testosterone.18 EWG gives oxybenzone a hazard score of 8 out of 10 in humans based on skin penetration, widespread use and links with skin allergies and hormone disruption.19
Oxybenzone: Sunscreen Chemical Damages Coral Reefs
The potential damage by oxybenzone is not limited to human health. Research has associated this chemical with death and damage to the vibrant coral reefs off the coasts of Hawaii and the Virgin Islands.20 An international team21 led by Craig Downs, Ph.D., forensic ecotoxicologist22 and executive director of Haereticus Environmental Laboratory, found the highest concentrations of oxybenzone along reefs popular with tourists in the Caribbean and along Hawaii's coastline.
Downs explained the concentration of oxybenzone illuminates why they didn't observe a healthy number of baby coral in the area, as oxybenzone is fatal to young coral and alters the DNA of adults, making them more prone to lethal bleaching and death. Even small amounts of the chemical have been shown to alter DNA in a baby coral, causing it to encase itself in its skeleton and die.
Oxybenzone also creates a situation in which the coral starves. Most reef building coral have a symbiotic relationship with tiny algae. The algae supply sugar for energy to the coral and the coral provides a sheltered home and carbon dioxide from metabolism to the algae.23 When the algae are poisoned by oxybenzone, the coral expel them and then die from lack of nutrients.
This means tourists snorkeling along the coral reefs for an up close and personal experience with one of nature's truly amazing and unique sights may well be depositing chemicals during their swim that are killing the reefs. In an effort to fight for the health of the local environment, Espero and his team put together a bill to ban the sale of sunscreen containing oxybenzone in Hawaii.
The irony is that damage to the environment by oxybenzone is more potent in sunny environments, and the sunnier the area the more sunscreen tourists use each day.24
As you may expect, this bill is being met with resistance by cosmetic companies as they predict a ban would have a large negative impact on their immediate revenue. However, while the bill was not successful in 2017, Espero and his supporters plan to continue to push for a ban on the sale of sunscreen with oxybenzone in Hawaii. If passed, it is likely other states will follow suit.25