Sunscreen Basics
Sunscreens work by using active ingredients that absorb, scatter, or reflect the UV radiation before it reaches the skin. By filtering out harmful UV rays, broad-spectrum sunscreens help to reduce the risk of skin cancer and premature skin aging, as well as help prevent sunburn.
Source: “Sunscreens: How to Read a Label, Expert Tips Etc.” Sunscreens: How to Read a Label, Expert Tips Etc. | Cosmetics Info. Accessed April 29, 2019. LINK.
A sunscreen can be labeled “Broad Spectrum” if it provides UV protection across both the UVB and UVA wavelength ranges. UV radiation in sunlight is divided into several ranges depending on the wavelength. UVB radiation covers the wavelength range between 290 and 320 nanometers, and UVA radiation is between 320 and 400 nanometers. Sunburn is primarily caused by UVB. UVB and UVA can cause sunburn, skin cancer and premature skin aging.
According to FDA, only products labeled with “Broad Spectrum” and SPF 15 or (higher) have been shown, if used as directed with other sun protection measures, to provide these benefits.
The Sun Protection Factor (SPF) of a sunscreen is a clinical test measure of the effectiveness of a sunscreen product against sunburn. The SPF indicates how long a person can be exposed to UV radiation before getting sunburned with a sunscreen applied compared to how long they can be exposed before getting a sunburn without sunscreen.
Sunscreen Usage
- Apply 15 minutes before you go outside. This allows the sunscreen (of SPF 30 or higher) to have enough time to provide the maximum benefit.
- Use enough to cover your entire face and sun-exposed areas of the body (avoiding the eyes and mouth). An average-sized adult needs at least one ounce of sunscreen (about the amount it takes to fill a shot glass) to evenly cover the body from head to toe when using beach products.
- Fair-skinned people are likely to absorb more solar energy than dark-skinned people under the same conditions. However, all skins tones need sun protection.
- When outdoors, reapply at least every two hours, and more often if you’re swimming or sweating and immediately after toweling dry.
Sunscreen Ingredients
Oxybenzone is one of the few FDA-approved ingredients that provides effective broad-spectrum protection from UV radiation, and has been approved for use since 1978. Oxybenzone in sunscreen is FDA approved for use on children older than six months.
- Contrary to some media reports, the currently available scientific research does not support a conclusion that oxybenzone in sunscreen causes hormonal alterations nor any other adverse health issues in humansi.
- Other sunscreen ingredients commonly used in the U.S.:ii
- titanium dioxide
- zinc oxide
- ensulizole
- octisalate
- homosalate
- octocrylene
- octinoxate
- avobenzone
- meradimate
Source i: Wang SQ, Burnett ME, Lim HW. Safety of Oxybenzone: Putting Numbers Into Perspective. Arch Dermatol.2011;147(7):865–866. doi:10.1001/archdermatol.2011.173 (https://jamanetwork.com/journals/jamadermatology/fullarticle/1105240)
Source ii: “Is Sunscreen Safe?” Is Sunscreen Safe? | American Academy of Dermatology. Accessed April 29, 2019. https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent/is-sunsceen-safe.
Sunscreen Effectiveness
Sunscreen effectiveness depends on a number of factors, including the SPF value, if the product provides broad spectrum protection, level of water resistance, and whether the product is used as directed.
No matter what the active ingredients, all FDA-approved sunscreen ingredients work by scattering, reflecting or absorbing UV rays. There is no difference in efficacy between sunscreens with organic or inorganic actives, as they all must be formulated to achieve their SPF label claim. All sunscreens in the United States must be tested for SPF performance using the same FDA designated clinical tests.
Testing methods used to develop sunscreen shopping guides (e.g. Consumer Reports, the Environmental Working Group) may not be consistent with those used by FDA, and therefore may not be accurate indicators of a sunscreens’ SPF designation.
Sunscreen Safety
Sunscreens are regulated by FDA as over-the-counter (OTC) drugs. As such, they must be shown to be both safe and effective and must comply with all other requirements listed in FDA’s OTC sunscreen monograph. Individual sunscreen active ingredients are reviewed by FDA and only those that are identified for use in the monograph may be used in sunscreen products marketed in the U.S.
Updates and changes to the monograph are issued via a public rule-making process. On February 26, 2019, FDA published the updated proposed rule for sunscreens, known as the Tentative Final Monograph (TFM). Because of deadlines imposed by the Sunscreen Innovation Act, FDA has stated that it must finalize the TFM by November 26, 2019.
The TFM addresses numerous aspects of sunscreen formulation and is comprehensive in nature. For instance, the TFM proposes what types of dosage forms sunscreens may be made in (e.g., sprays, lotions, etc.), what information must be included on the labeling, the maximum allowed value of the SPF, and requirements for using broad-spectrum claims. Additionally, one of the key areas that the TFM addresses are the active ingredients that may be used in sunscreens as UV filters.
Previously, there were 16 permitted active ingredients for use in the United States. In the TFM, FDA identified two of the 16 ingredients, zinc oxide and titanium dioxide, as meeting FDA’s established conditions for safety and effectiveness. FDA requested that industry provide additional information on 12 ingredients currently used in sunscreens in the U.S. and around the world in order to support a generally recognized as safe and effective (GRASE) standard. Industry has committed to the FDA that we will work with the agency to provide information sufficient for them to conclude that the ingredients are GRASE.
No. Janet Woodcock, M.D., director of FDA’s Center for Drug Evaluation and Research (CDER) stated: “It is important that, as this rulemaking effort moves forward and FDA gathers additional scientific information, given the recognized public health benefits of sunscreen use, consumers continue to use sunscreen in conjunction with other sun-protection measures.”
Source: Commissioner, Office Of the. “FDA Advances New Proposed Regulation to Make Sure That Sunscreens Are Safe and Effective.” FDA Advances New Proposed Regulation to Make Sure That Sunscreens Are Safe and Effective. Accessed April 29, 2019. https://www.fda.gov/news-events/press-announcements/fda-advances-new-proposed-regulation-make-sure-sunscreens-are-safe-and-effective.
Sunscreen and Children
The American Academy of Dermatology (AAD), the American Academy of Pediatrics (AAP) and FDA all recommend the following when using sunscreen on babies and toddlers:
Children younger than 6 months of age:
- Babies under 6 months should not spend time directly in the sun. Since babies’ skin is much more sensitive than adults, sunscreens should be avoided whenever possible.
- Protect their skin from the sun by keeping them in the shade and dressing them in long-sleeved shirts, pants, wide-brimmed hats, and sunglasses.
Children 6 months of age and older:
- Parents should apply an SPF 30 or higher sunscreen to their children’s exposed skin every morning, at least 15 minutes before going outside. If they will be spending extended time outdoors, use a water-resistant, broad spectrum sunscreen with an SPF of 30 or higher.
- Even when using sunscreen, keep children in the shade and dress them in clothing that will protect their skin from the sun, i.e., long-sleeved shirts, pants, and wide-brimmed hats.
Adults should help children reapply their sunscreen at least every two hours and after swimming, playing sports or toweling dry. If your child can apply their own sunscreen, remind them about easy-to-miss spots (i.e., backs of ears and neck, tops of feet and hands).
Parents should look for sunscreens that are specifically designed for children as these are sometimes tested by pediatricians and may have additional benefits to prevent stinging or tearing if they get it in their eyes. In addition, typically these products utilize colors and images that may get children excited about wearing sunscreen. It’s important to remember that the best sunscreen is the one that they are likely to use!
Both inorganic and organic broad-spectrum sunscreens are designed to stay on the skin and are safe. Active ingredients like titanium dioxide and/or zinc oxide may be less likely to irritate a baby’s sensitive skin.
Some schools prohibit students from possessing sunscreen due to its classification as an over-the-counter drug medication.
PCPC partners with the AAD and the American Society for Dermatologic Surgery Association (ASDSA) on a public health initiative called SUNucate to spread awareness about the importance of sun-protective behaviors and to remove barriers that prohibit access to important sun-protective measures, such as sunscreen and sun-protective clothing.
To date, 22 states have passed SUNucate-related measures with several other states pending action.
Sunscreen and the Environment
No, scientific evidence does not support a connection between sunscreen ingredients and coral decline. Scientists around the world cite pollution, global warming and overfishing as the leading causes of coral bleaching. According to the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Coral Reef Conservation Program, an increasing array of hazards impact coral reefs – primarily from effects of pollution (acidification and runoff), global climate change and unsustainable fishing practices.
Source: National Oceanic and Atmospheric Administration (NOAA) – https://aambpublicoceanservice.blob.core.windows.net/oceanserviceprod/facts/coralbleaching.pdf
Allegations linking oxybenzone and coral bleaching are based largely on one flawed laboratory study published in 2015 in the Archives of Environmental Contamination and Toxicology. Numerous scientists have questioned the study’s erroneous conclusions. Even the study’s author, Craig Downs said, “My professional opinion is that agricultural run-off and sewage…are probably responsible for the historical collapse of coral reefs for the past 40 years.”
Source: Mashable Australia, 2015: https://mashable.com/2015/11/10/sunscreen-killing-coral-reefs/#e5rE4eYb85qS
A recent study measured levels of sunscreen ingredients in seawater, sediment and coral tissue in Hawaii. Extremely small amounts of sunscreen ingredients were detected, while others could not be detected at all. When sunscreen ingredients were detected, the levels found were in the low to mid parts per trillion range, which is equivalent to adding one drop of an ingredient into a tanker truck of water or adding 10 drops of an ingredient into the Rose Bowl filled with water.
Source: Mitchelmore CL, He K, Gonsior M, Hain E, Heyes A ,Clark C, Younger R, Schmitt-Kopplin P, Feerick A, Conway A, Blaney L. 2019. Occurrence and distribution of UV-filters and other anthropogenic contaminants in coastal surface water, sediment, and coral tissue from Hawaii. Science of the Total Environment 670:398-410.
There is little evidence that removing sunscreen ingredients from marine ecosystems would help coral. Little to no evidence supports sunscreen as a coral stressor, and no real-world marine study has shown banning this non-stressor would contribute to coral recovery.Sunscreen is not a proven cause of coral decline and banning sunscreens containing specific ingredients – based on one study – eliminates one of the most effective product categories that protects us from skin cancer, risking a public health crisis without any proven benefit for coral reefs.