So, which sunscreens are safe and effective?
Sunscreen can be a baffling topic. One study claims they are safe, while another suggests they are toxic. Even the studies and reports that indicate sunscreens are only mildly bad for you cause many of us to skip using them altogether, “just in case”. I have children with children of their own, and like most of us, they are aware that excessive sun exposure can come back to haunt us in our later years as various forms of skin damage and even cancers.
Let’s see if we can pull together some realistic and easy-to-understand information so that we can all make the best decisions for ourselves and those we love.
Much of the following information is sourced from ConsumerLab.com. It is an independent database that purchases products from various sources and tests each one to ensure it meets quality standards and delivers what the label claims. The information given on the website at https://www.consumerlab.com is far more detailed and comprehensive, so I have edited their lengthy analysis.
As always, let’s start with the basic information.
What is it about sunscreens that we deem ‘unsafe’?
Chemicals and compounds.
As noted by the American Academy of Dermatology, octocrylene is among a dozen chemical sunscreen agents classified as not generally recognized as safe and effective. Other common sunscreen compounds in this category are avobenzone, ensulizole, homosalate, octinoxate, octisalate, and oxybenzone. A 2020 clinical study showed that each of these compounds is absorbed into the body, resulting in concentrations that exceeded safety thresholds.
The only two compounds considered generally safe and effective as sunscreens are the mineral compounds titanium dioxide and zinc oxide. They essentially work by blocking ultraviolet radiation, while chemical sunscreen agents absorb radiation. A 2014 European Commission report indicated that there is very little absorption of zinc oxide and titanium dioxide into the body when applied to the skin, regardless of particle size.
These two compounds are also more environmentally safe for swimming near coral reefs than chemicals, although one laboratory study suggested that even titanium dioxide might damage sea urchin larvae. Be aware that terms such as "reef-safe" and "reef-friendly" are not defined or regulated.
Some sunscreens are available as a spray, but nano-sized particles may be unsafe when inhaled because they may reach the airways of the deep lung, so opt to use sunscreen lotion or at least hold the container close to the skin and spray onto a hand before applying to the face.
Zinc oxide provides protection against both UVB (which causes sunburn) and UVA (which contributes to wrinkles and age spots), while titanium dioxide primarily protects against UVB and offers less protection against UVA. It may, therefore, be better to choose sunscreen with only zinc oxide than a combination of zinc oxide and titanium oxide. Sunscreens containing titanium dioxide and zinc oxide were more likely to fail requirements for UVA protection than those containing only zinc oxide. Additionally, testing revealed that products containing zinc oxide and titanium dioxide generally provided lower UVA protection than those containing only zinc oxide.
To ensure you use a product that provides sufficient protection, choose a sunscreen with an SPF of at least 30 and ensure it is "broad spectrum,” which means it protects against both UVB and UVA rays. Avoid sunscreens that combine otherwise safe mineral-based ingredients (such as zinc oxide or titanium dioxide) with organic chemical formulas, particularly those containing avobenzone.
Tinted sunscreens can provide added protection against the adverse skin effects of visible (not UV) light for some people with skin disorders or conditions caused by an abnormal reaction to sunlight exposure. Some conditions can be aggravated by visible light, and tinted sunscreens can reduce the transmittance of visible light, while mineral and chemical sunscreens do not.
Regardless of the type of sunscreen you use, it is recommended that you reapply sunscreen every two hours, more often if you are swimming or sweating. Furthermore, most people apply only ¼ to ½ the amount of sunscreen needed to get the expected SPF protection. You’ll generally need to use 2 mg of sunscreen per square centimetre of skin, or approximately two tablespoons for the average-sized adult body.
A chemical-based sunscreen may be best if you expect to be in the water for an extended period. Otherwise, use a mineral-based sunscreen that is a healthier alternative. Also, be aware that octocrylene may cause redness and inflammation in a smaller percentage of people. The sunscreens that performed best in Consumer Reports’ testing were lotions with an SPF of 50 that were “water resistant (80 minutes). All contained a combination of avobenzone, homosalate, octocrylene, and octisalate as their active ingredients, although not necessarily in that order.
Be aware that when using sunscreens in conjunction with insect repellents, the sunscreen should be applied before the repellent. Additionally, insect repellents may reduce the effectiveness of sunscreens, so they may need to be reapplied more frequently.
Some mineral sunscreens contain butyloctyl salicylate, a compound similar to the chemical UV filters homosalate and octisalate as an “SPF booster” because it can absorb some UV rays. However, since it is not classified as an active sunscreen ingredient, it is listed only as an inactive ingredient on sunscreen labels and may be included in mineral sunscreens. People choosing to use mineral sunscreens to avoid damaging coral reefs or because they have concerns about absorption of chemical sunscreen ingredients may wish to avoid mineral sunscreens containing this ingredient, as butyloctyl salicylate might be harmful to aquatic life, and it is absorbed into skin like chemical UV filters.
Benzene, which has been linked to blood cancers, was reported in 2021 in a large number of sunscreens and after-sun products that were independently tested. A study by Health Canada's Bureau of Chemical Hazards has shown that the application of sunscreen specifically increases the absorption rate of benzene through the skin. No level of benzene is safe, and it is not permitted in these or other products. However, while it's not intentionally added to most skin products, it can be found as a contaminant in certain formulations, especially those containing fragrances, solvents, or propellants. Studies have shown trace amounts of benzene can be present in sprays, lotions, and sunscreens. (Shade dermatology.com, Feb 5, 2025)
What are "DNA repair enzymes" in sunscreens, and do they reverse sun damage?
It is unclear whether the use of skin products containing "DNA repair enzymes" (which are expensive) actually reduces the effects of sun damage, let alone reverses it. A panel of cosmetic dermatology experts, who evaluated nearly 90 cosmetic ingredients for several skin concerns, did not recommend DNA repair enzymes for any skin benefits.
Is sun-protection clothing effective?
Sun-protection clothing is made with fabric that has been tested and rated for its level of protection based on the ultraviolet protection factor (UPF) scale. On the UPF rating scale, ratings of 15, 30, and 50+ correspond to clothing that blocks 93.3%, 96.7%, and 98% of UVB radiation, respectively.
Compared to sunscreens with SPF 30 or SPF 50, sun-protection fabrics block a much greater percentage of UVA and UVB rays. The sun-protection fabrics included woven nylon (common in swimwear and undergarments), pique knit polyester (common in polo shirts), interlock knit polyester (common in stretchy fabrics for activewear), or interlock knit polyester with a titanium dioxide dot print.
Keep in mind that any clothing can help protect skin from UV radiation, even if it is not specifically labelled as "sun protective"; however, the type and colour of fabric influence its effectiveness. Fabric that is dark or bright (e.g., red, black or navy) and fabric that is less porous (e.g., polyester, cotton blends, fabric used in polo shirts) tend to protect against UV radiation better than light-colored fabrics (e.g., pastels, yellow, or white) and fabrics that are porous (e.g. linen, knitted fabrics).
Next week, we’ll explore any supplements or foods that may help prevent sunburn or skin damage from sun exposure. Stay tuned!
Photo from https://www.ewg.org/news-insights/news/five-ways-get-your-kid-wear-sunscreen
