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A new indicates that many people are unaware of basic sun protection principles. Do you know what SPF means? What is a broad spectrum sunscreen? Increase your sun protection awareness so you can stay protected.

A study of 114 participants recruited from a dermatology clinic in Chicago, Illinois, United States, has demonstrated that the average person has a poor understanding of labelling on sunscreens. The participants answered questions regarding their skin type, sunscreen purchasing behaviours, and their understanding of the descriptions on the sunscreen labels. The participants were also surveyed to determine their general knowledge about sun protection.

The study, published in the Journal of the American Medical Association Dermatology, found that less than 50% of participants could interpret sun protection factor (SPF) in relation to protection against sunburns. The study also reported that only 49 participants, out of the 114 surveyed, understood the definition of SPF value. The majority of participants were aware that a higher SPF value was indicative of greater protection against sunburn. Additionally, the majority of participants were also aware that staying out of the sun is better than sunscreen for prevention of skin cancer. Just over half of participants reported the correct amount of sunscreen to apply in order to get maximum benefit.

Overall the study demonstrated that knowledge of sun protection and language used on sunscreen labels are not completely understood by consumers. The researchers suggest that due to commonly held misconceptions regarding sun protection, and in particular, SPF, health care providers should aim to educate patients regarding the need for both UV-A and UV-B protection, and the dangers of sunburns and skin cancers.

What is UV-A Radiation?

UV-A rays constitute the longest of the UV rays, with a wavelength 320-400nm. UV-A exposure is highest because the majority of UV rays that reach the earth are UV-A. UV-A radiation is involved in aging of the skin (photoaging), however, more recent research has implicated UV-A in the development of skin cancers.

What is UV-B Radiation?

UV-B rays are shorter in wavelength, at 290-320nm. UV-B rays are primarily responsible for sunburn, and damage to the outer layers of the skin. UV-B plays a key role in skin cancer development, with some influence on photoaging.

What does SPF mean?

Sun Protection Factor (SPF) is a measure of the effectiveness of sunscreen. It is a measure of the time it would take for UV-B radiation to cause skin redness when using sunscreen compared to no sunscreen. For example, an SPF of 30 indicates that if you apply this sunscreen, it would take 30 times longer for your skin to redden, compared to if you did not apply the sunscreen.

What Does ‘Broad Spectrum’ Mean?

A broad spectrum sunscreen is a sunscreen that protects against both UV-A and UV-B radiation.



Betty Y. Kong, Sarah L. Sheu, Roopal V. Kundu. “Assessment of Consumer Knowledge of New Sunscreen Labels.” JAMA Dermatology, 2015; DOI: 10.1001/jamadermatol.2015.1253

UV-A and UV-B Fact Sheet Available from Last Accessed: June 19, 2015.

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Written by Deborah Tallarigo, PhD

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