The convenience of spray sunscreens has made them a popular choice for sun protection. However, a growing public discussion centers on the potential environmental impact of these products. This article explores whether spray sunscreen is harmful to the environment, examining its components and delivery mechanisms.
Harmful Ingredients in Spray Sunscreen
Spray sunscreens often contain chemical UV filters and sometimes mineral filters in nanoparticle form, both of which can pose environmental concerns. Chemical filters like oxybenzone (benzophenone-3) and octinoxate are designed to absorb ultraviolet (UV) radiation. These compounds have been identified in water sources globally and are not easily removed by standard wastewater treatment processes.
Studies have implicated oxybenzone as a potential contributor to coral reef bleaching by activating coral viruses and causing oxidative stress. Octinoxate has also been linked to coral bleaching. Both oxybenzone and octinoxate can disrupt the endocrine systems of fish, potentially altering reproductive behaviors and patterns.
Mineral filters, such as zinc oxide and titanium dioxide, are considered less harmful than chemical filters when in their non-nanoparticle form. However, when these minerals are manufactured as nanoparticles, their environmental impact changes. Nanoparticle zinc oxide (ZnO NPs) can aggregate in high-salinity environments, and smaller nanoparticles exhibit higher reactivity and bioavailability, increasing their potential for bioaccumulation in aquatic organisms. Exposure to ZnO NPs has been linked to oxidative stress, developmental abnormalities, and behavioral changes in aquatic organisms. Similarly, titanium dioxide nanoparticles (TiO2 NPs) can accumulate in water and soil, potentially affecting the growth and reproduction of aquatic organisms and altering microbial communities. They have also been shown to cause oxidative stress in aquatic organisms like fish and algae.
Environmental Impacts of Spray Sunscreen
When chemical UV filters like oxybenzone and octinoxate wash off skin, they enter aquatic systems, including oceans, rivers, and lakes. These chemicals contribute to coral bleaching, a process where corals expel the symbiotic algae they rely on for energy, leading to stress and potential death. Oxybenzone can damage coral DNA and impair their ability to reproduce and grow, impacting coral populations even at low concentrations.
Beyond corals, these chemicals affect other marine life. Oxybenzone and octinoxate can disrupt hormone function, cause DNA damage, and impair reproductive success in species like fish, sea turtles, and marine mammals. These UV filters have been detected in various fish species worldwide, raising concerns for the food chain. Nanoparticles can also accumulate in the food chain, with potential for biomagnification at higher trophic levels.
The Problem with Aerosol Delivery
Beyond the chemical composition of the sunscreen itself, the aerosol delivery system used in spray sunscreens presents environmental concerns. These products often rely on propellants to dispense the sunscreen, many of which are volatile organic compounds (VOCs). When released into the atmosphere, VOCs can contribute to the formation of ground-level ozone, a primary component of smog, which can negatively impact air quality.
Another issue is overspray, which occurs when a significant portion of the sprayed product misses the skin and disperses into the surrounding environment. This overspray means more sunscreen chemicals are released directly into the air, soil, and water, rather than remaining on the user’s skin, increasing the environmental burden. The dispersed nature of spray sunscreen also means that some of the product can be inhaled by users during application.
Environmentally Friendly Sunscreen Alternatives
For environmentally responsible sun protection, several alternatives to spray sunscreens exist. Non-nano mineral sunscreens, which use zinc oxide and titanium dioxide as active ingredients, are generally considered a better choice. These formulations typically use larger mineral particles that sit on the skin’s surface rather than being absorbed, and they are less likely to harm marine life compared to their nanoparticle counterparts. When selecting these products, looking for “non-nano” on the label helps ensure the particles are large enough not to be readily absorbed by marine organisms.
Sunscreen in lotion or stick form also reduces the environmental impact associated with aerosol propellants and overspray. These applications allow for more precise and contained delivery of the product, minimizing unintended release into the environment. Beyond topical sunscreens, other protective measures offer primary sun protection. Wearing UPF (Ultraviolet Protection Factor) clothing, which is specifically designed to block UV radiation, provides a physical barrier against the sun’s rays. Seeking shade during peak sun hours also effectively reduces UV exposure without relying on chemical or mineral filters.