Those who use sun lotion four times or more a day enrich the blood with ingredients of the protective agent which, according to a recent toxicological study, are at least worth checking. But nobody should do without the sun protection that is necessary these summer days.
Sun creams and sun tanning lotions have long been recommended as a pillar of skin protection against dangerous UV radiation by international guidelines as well as by professional associations worldwide. However, sunscreen products pose a serious problem: classified as cosmetics, they must be approved, but clinical trials are not planned. Animal experiments in the field of cosmetics were banned years ago.
Unlike in Europe or in Germany, US authorities are already taking action when components of cosmetic products are systemically absorbed to more than 0.5 ng/ml. And this is exactly how this story about sun lotions began.
A recent toxicological study discovered that people (mainly of African-American origin in the study) applied four times or more sunscreen a day and clearly exceeded this limit. This means that a toxicological assessment of sun protection products is now actually necessary, including an assessment of systemic carcinogenicity or possible fetal damage during pregnancy.
Six study participants each received cream, lotion or spray and had to apply the respective formulation 4 times daily. Over the course of seven days, a total of 30 blood samples were taken from each volunteer. In these, the average concentration of the following sun protection components was determined: Avobenzone, oxybenzone, octocrylene, and ecamsul.
As a result, the limit value of 0.5 ng/ml for the systemic absorption of cosmetic ingredients was clearly exceeded. Depending on the component and formulation, the exceedances ranged between 3 times and 420 times the permissible limit values.
The study is unlikely to have any effect on the use of sunscreens at first, and the authors also stress once again that their results must not be interpreted as a vote against the important skin protection products. However, the finding ignites a much needed further debate and should lead to continuing, larger toxicological studies to better assess the clinical significance and relevance of systemic absorption of components in sun creams.
Source:
Matta MK et al., Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial. JAMA 2019: doi: 10.1001/jama.2019.5586