Consumers may not understand the range of SPF numbers on sunscreen products, and some may not be using sunscreens properly, according to recent research from the American Academy of Dermatology.
Only 32% of respondents in a 2016 AAD survey knew that an SPF 30 sunscreen does not offer twice as much protection as an SPF 15 sunscreen, according to a press release. In addition, only 45% of respondents knew that a higher-SPF sunscreen does not offer a longer duration of sun protection than a lower-SPF sunscreen, the release reported.
“It’s important that everyone understands what they are seeing on a sunscreen label,” Abel Torres, MD, JD, FAAD, president of the AAD, stated in the release. “A sunscreen with an SPF of 30 blocks up to 97% of the sun’s rays. Higher SPFs block slightly more rays, but a higher number SPF does not allow you to spend more time outdoors without reapplication; all sunscreens should be reapplied every two hours, or after swimming or sweating.”
Most of the survey participants (85%) knew that sunscreen needs to be reapplied after swimming. However, data from a study published this month in the Journal of the American Academy of Dermatology suggest that some people might be incorrectly using sunscreen, according to the release.
Researchers from the Johns Hopkins University School of Medicine studied 758 people with a history of nonmelanoma skin cancer and 34,141 controls. The patients with a history of skin cancer were more likely to seek shade, wear protective clothing and apply sunscreen, but still received sunburns as often as the control group, according to the release.
“While it makes sense that people with a history of skin cancer were more likely to practice sun protection, we were surprised to see their methods were not always effective,” researcher Anna L. Chien, MD, FAAD, stated in the release. “Our results reinforce the importance of everyone using multiple types of sun protection; people who rely only on sunscreen may not be applying enough, covering all their exposed skin or reapplying enough to shield themselves from the sun’s harmful UV rays.”