From the moment you apply them, sunscreen chemicals can be absorbed into your blood stream. [Photo: Bigstock]

Sunscreen chemicals easily absorbed into the bloodstream

9 May, 2019

Natural Health News —  With regular use the chemicals in your sunscreen can be absorbed into the bloodstream at levels high enough to raise concerns about toxic effects.

That’s the conclusion of a small study conducted by researchers at the US Food and Drug Administration (FDA).

The 23 volunteers tested four sunscreens, including sprays, lotion and cream, applying the formulations to 75% of the body four times a day over four days. This regimen was chosen because it is in line with standard manufacturers’ instructions to apply sunscreen at least every 2 hours during the day.

The researchers used blood tests to determine the maximum levels of certain chemicals absorbed into the bloodstream.

The results, published in the Journal of the American Medical Association (JAMA), found that chemical levels in the blood began to rise on the first day of use and, with continuing use of the sunscreens, the levels of sunscreen chemicals detected in the blood also continued to rise, suggesting that these chemicals may accumulate in the blood over time.

Maximum plasma levels of the chemicals it tested for – avobenzone, oxybenzone, octocrylene and, in one sunscreen, ecamsule – were well above the level of 0.5 nanograms per millilitre (ng/mL) at which FDA guidelines call for further safety testing.

FDA calls for further testing

Commenting on the study on its website, the FDA said: “The fact that an ingredient is absorbed through the skin and into the body does not mean the ingredient is unsafe. Rather, this finding calls for further testing to determine the safety of that ingredient for repeated use. Such testing is part of the standard pre-market safety evaluation of most chronically administered drugs with appreciable systemic absorption.”

The Agency suggested that since it began regulating sunscreens in the 1970s, its understanding of drug absorption through the skin and the ability to measure drug absorption have advanced. It’s not entirely clear if human safety testing has kept up with this evolving understanding, however. In fact, sunscreen creams have largely avoided extensive safety tests because absorption had previously been thought to be minimal.

Hormone disruption

The findings could hardly have been a surprise. The authors note, for example, that past studies have found oxybenzone and octocrylene have been found in human breast milk. Oxybenzone has also been identified in urine, blood and amniotic fluid.

Animal studies have raised concerns that the chemicals, oxybenzone in particular, might disrupt normal hormone patterns in people, the researchers noted in their study. We have previously reported on research showing that chemical sunscreening agents called benzophenones may raise the risk of developing endometriosis and may also contribute to male infertility. But overall  there is very little study of how these chemicals behave in the body of adults or children.

Stick to mineral formulations

Most sunscreens on the shelf use chemicals like oxybenzone, avobenzone and octocrylene to block harmful rays. These chemicals absorb ultraviolet radiation and convert it into a small amount of heat.

If you are concerned about the safety of conventional chemical sunscreens try swapping to mineral sunscreens and more natural formulations. These rely on zinc oxide and titanium dioxide, which reflect sunlight from the skin, rather than absorbing it. Natural and organic formulations will also have fewer worrying ingredients like parabens.