The chemicals have been absorbed through the skin, and into the blood where amounts that are up to hundreds of times above recognised safety levels have been detected.
The high levels in blood plasma samples are from people who have applied the creams and sprays correctly, and according to the manufacturer's recommended guidelines.
America's Food and Drug Administration (FDA) has set a safety threshold of 0.5 ng/mL in blood plasma for the active ingredients found in most sunscreens—but levels of up to 209 ng/mL have been detected by FDA researchers, who tested four popular products on 24 volunteers.
Any level above 0.5 ng/mL should trigger an automatic toxicology assessment because the chemicals—avobenzone, oxybenzone, octocrylene and ecamsule—could be cancer-causing and may interfere with healthy development and reproduction.
In the test, the four sunscreens—two sprays, one lotion and one cream—were applied to the volunteers, whose blood plasma was tested. Oxybenzone was the most easily absorbed, with levels as high as 209.6 ng/mL being detected.