Indie sunscreen brand Love Sun Body is expanding its line of natural mineral sunscreens, and supports the FDA's recent call for more research on chemical ingredients commonly used in sunscreen formulas.
For example, the maximum concentration of avobenzone was found to be 4 ng/mL and 3.4 ng/mL for two different sprays, 4.3 ng/mL for a lotion and 1.8 ng/mL for the cream. They were applied as directed four times a day (as we are all supposed to do). Millions of people use sunscreens with an SPF of over 15 when stepping out.
First author Murali K. Matta and colleagues included 24 healthy participants who applied the 4 commercially available sunscreen formulations.
"Rather, this finding calls for further testing to determine the safety of that ingredient for repeated use", said a statement by Woodcock and Michele on the FDA's website.
"Avoidance of the sunscreen ingredients highlighted in this study, or of sunscreen altogether, could have significant negative health implications".
"Similar studies show that physical blockers such as zinc and titanium are also absorbed. However, these studies do not conclude that sunscreen absorption is risky", Farberg told MedPage Today.
Laurel Geraghty, MD, of Dermatology & Laser Associates in Medford, Oregon, said it was "too early to draw any clinical conclusions based on this small study evaluating the systemic absorption of four sunscreen ingredients".
Some types of sunscreens can seep chemicals into your bloodstream, a Food and Drug Administration study found.
The FDA says need more research is needed before the chemicals can be considered safe and effective.
The investigators assessed 24 participants (mean age 35.5; 58% black or African American; 50% women) at a USA phase I clinical pharmacology unit. For octocrylene absorption level was 2.9 ng/mL, 7.8 ng/mL, 5.7 ng/mL and 5.7 ng/mL for 2 sprays, lotion and cream respectively. The team collected 30 blood samples over 7 days from each of the participants. If the absorption exceeds 0.5 ng/mL, the FDA recommends "nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies". For oxybenzone similarly the values were 209.6 ng/mL, 194.9 ng/mL, 169.3 ng/mL for spray 1, 2 and lotion respectively. According to this latest study, these four ingredients in question have a higher than the 0.5 ng/mL absorption in blood. For ecamsule the values were 1.5 ng/mL for the cream.
"While the current study was purposefully created to represent maximal usage per sunscreen labels (i.e., apply at least every 2 hours) to areas of the body outside of normal swimwear over multiple days as [what] might occur at the beach, absorption exceeding 0.5 ng/mL occurred on day 1 and three of the four active ingredients lasted until day 7", the authors pointed out. Also, the authors did not assess single-dose application.
Commeting on the latest study, former FDA Chairman Dr. Robert Califf assured that the results of the study do not "mean these ingredients are unsafe".
Upon analyzing plasma levels in the participants' blood samples, scientists found that the level of active ingredients in their bloodstreams was high enough to spark a government investigation.