Is Sunscreen Safe?

11150753699?profile=RESIZE_710xRegardless of the season or amount of time spent at the beach, on the slopes, or retrieving the daily newspaper, our skin accumulates a lifetime of effects from the sun’s ultraviolet radiation. Sunscreen helps protect skin and prevent sunburn, the appearance of premature aging, and skin cancer. On May 23, 2023, the non-profit consumer advocacy group EWG (Environmental Working Group) published their "Guide to Sunscreen." The report says only 25% of sunscreens offer broad-spectrum protection without “troublesome ingredients.” So far, only three brands with 12 products have passed the strict verification standards, but the list is expected to grow. One positive item in the report said that the use of oxybenzone, which has been linked to harm to human health, is declining. According to the highly regarded Haereticus Environmental Laboratory, which suggests looking for the "Protect Land and Sea Certification Seal" on products, oxybenzone and a host of other chemicals cause the destruction of coral reefs. Let’s take a look at the categories of sunscreens and see if protecting skin while caring for the environmental is simultaneously possible.

Chemical sunscreen vs. physical sunscreen

Chemical sunscreens contain organic (carbon based) compounds like oxybenzone, avobenzone, octisalate, octocrylene, and homosalate that work by absorbing and transforming UV rays into heat, which is then released from the skin. They are usually thinner than physical sunscreens, absorb more readily into the skin, and leave less residue. The UV filters in chemical sunscreen protect against longer UVA rays or shorter UVB rays but not both, whereas physical sunscreens block both. Chemical sunscreens should be applied 20 minutes before sun exposure and then reapplied frequently to be effective. The ingredients tend to be more irritating to the skin and eyes than physical sunscreens, but what’s more troubling is that some of the chemicals are photosensitizers, meaning they increase the body’s production of free radicals after sun exposure, and they are also implicated as hormone disruptors, which may affect the production of estrogen in the body. Some sunscreens will have labels that say "avobenzone-free" or "oxybenzone-free" and yet they contain octocrylene. Octocrylene breaks down into benzophenone, which is an endocrine disruptor. According to Haereticus Environmental Laboratory, benzophenone affects thyroid function causing anti-androgenic activity, delays testicular development and anatomic difficulties with female reproductive organs." Sunscreens with octocrylene have been banned in the U.S. Virgin Islands and other places, and the list is growing.

Physical sunscreens, also called mineral sunscreens, almost always contain zinc oxide or titanium dioxide, the only physical UV filters approved by the FDA. These naturally occurring ingredients are considered safe and work by blocking and reflecting UV radiation before it can penetrate the outer layer of the skin. Mineral sunscreens offer broad-spectrum protection and are considered hypoallergenic and non-comedogenic, so they are less likely to irritate the skin, making them a good choice for those with acne, sensitive skin, or rosacea. Traditional physical sunscreens have been used for decades but may give a trademark white “lifeguard nose” appearance because their bulkier particles reflect visible light. Modern formulations of mineral sunscreens use tiny nanoparticles to absorb and scatter visible light, rendering them more transparent on the skin. But are these nanoparticles safe?

Size matters

Nanoparticles are microscopic particles that are 80,000 times smaller than the width of a hair, and there has been much debate on whether they do more harm or good to people and the environment. Some sunscreens with zinc oxide and titanium oxide use nanotechnology. Since the molecules are small, they are more readily absorbed into the skin and can better protect from ultraviolet radiation. Scientists have been concerned about whether metal oxide nanoparticles have the ability to penetrate the epidermis, which could conceivably cause cell and DNA damage. They maintain that larger, non-nano particles are safer.

Manufacturers are not obligated to label particle size on sunscreens, making it difficult for consumers to identify sunscreens that do contain nanoparticles. The only method of avoiding nanoparticle-containing sunscreens is to choose a chemical sunscreen. Although some sunscreen companies market clear zinc sunscreen as “non-nano” to quell any fears, more recent studies indicate that consumers need not worry because zinc and titanium dioxide do not penetrate the skin, regardless of size, nano or not. RMIT University toxicology expert Paul Wright says, "There's a negligible penetration of sunscreen nanoparticles. They don't get past the outermost dead layer of human skin cells, of which millions are shed each day." Furthermore, the human immune system is equipped with cells that would collect and break down any nanoparticles that make it through the skin. Critics argue that although nanoparticles generally have low toxicity and are inert and biocompatible, more research is needed to ensure safe use. Either way, EWG firmly discourages ingesting or inhaling nanoparticles from spray sunscreens and cosmetic loose powders. In part, this is because lungs have trouble clearing out tiny particles of benzene and other cancer-causing ingredients in aerosolized products. On their website, the EWG also states that they “remain deeply concerned about the general lack of oversight of nanotechnology and associated risks to consumers, people with workplace exposures and the environment. Government regulators should…ensure that the production, use and disposal of nanomaterials does not harm workers and the environment.”

What About the Environment?

While humans need sunscreen to protect their skin from ultraviolet rays and prevent skin cancer, chemicals found in many commercial sunscreens, even those labelled “reef safe” may pose a threat to the environment. Sunscreen ends up in the ocean and other waterways after you swim or shower it off. Ingredients like oxybenzone and octinoxate (found in chemical sunscreens) as well as nano titanium dioxide and nano zinc oxide (found in physical sunscreens) can harm coral reef, algae, fish, sea urchins, and other aquatic organisms. Zinc oxide and titanium oxide that use nanotechnology can cause oxidative stress in sunlight (coral bleaching), which damages hard corals and their symbiotic algae. In 2018, Hawaii became the first state to ban the sale of sunscreens containing oxybenzone and octinoxate. So, is reef-safe sunscreen that is okay for the environment but also effective for protecting humans possible? According to some experts, further research is needed. postulates that “studies undertaken in lab environments may fail to capture conditions on the reef, where pollutants are quickly dispersed and diluted. However, while the concentrations of sunscreen ingredients used in some research may be higher than those in natural environments, the negative impact of these chemicals on aquatic organisms is unmistakable.” Products that contain mineral oil and petroleum should also be avoided because they are toxic to marine life and take a long time to break down.


  • For purists, the only truly environmental option for sun protection is to cover up with long sleeves, hats, and sunglasses, stay in the shade, and avoid being in the sun during peak UV radiation hours. At the same time, ultraviolet radiation is a proven human carcinogen, causing squamous cell carcinoma and basal cell carcinoma, which can develop into melanoma. Studies have proven that sunscreen reduces rates of non-melanoma and melanoma skin cancers. Some people limit sunscreen use to the face, neck, and hands and are discerning about which sunscreens they buy. 
  • What kind of sunscreen should we use? Many dermatologists feel that the best sunscreen is the one their patients will use consistently, but safer choices are zinc oxide and titanium dioxide based physical sunscreens. There is controversy over zinc oxide and titanium dioxide sunscreen that uses nanotechnology, which is not supposed to be harmful to humans but may be harmful to marine life. You may look for non-nano sunscreens (with particles above 150 nanometers in diameter) from transparent companies such as Raw Elements or Badger Balm. In response to a customer who asked if the company used non-nano zinc, Badger Balm replied: “Different agencies around the world have different parameters that define ‘nano’ or ‘non-nano,’ so we have opted not to use this language on our packaging of our sunscreens. The clear zinc particles in our sunscreens range from 5 to 90 times larger than 100nm. Nanoparticles are any particles smaller than 100nm, or 100 billionths of a meter. They contain no free nanoparticles. This is independently verified using light scatter analysis that is very effective at identifying free nanoparticles. Clear zinc oxide has the same outstanding safety and efficacy of standard non-nano zinc oxide. It won't absorb into your body, it won't harm the environment, and it provides excellent UVA and UVB protection.”
  • 80% of all marine waste is plastic. Look for eco-friendly packaging alternatives like aluminum tins or biodegradable package options such as tubes and cardboard containers. Attitude sunscreen is EWG verified and comes in a cardboard tube, while some Badger Balm products come in tins.
  • Consult with EWG's excellent Sunscreen Guide for 2023 for more information.
  • Visit this Reef Safe Sunscreen Guide.

Sources and further reading:,which%20can%20cause%20skin%20irritations.,Discussion,in%20prevention%20should%20be%20encouraged,them%20transparent%20on%20the%20skin.

Photo by Juriel Majeed on Unsplash

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