Sunscreen: how its ingredients harm us while protecting us from ultraviolet radiation
'13.06.2023'
Lyudmila Balabay
Summer, sun - sounds great. But this kit has one drawback - ultraviolet radiation, which can cause burns or even potentially fatal diseases. Sunscreen is recommended to protect against this radiation. But they, too, are not the juice of the tree of life, but consist of chemicals whose safety for the skin (especially with daily abundant use) is questionable. Yes, manufacturers are testing sunscreens for toxicity, irritation and skin allergies. But what about their long-term effect?
In 2019, after a large study, the federal Food and Drug Administration (FDA) concluded that only two sunscreen ingredients—zinc oxide and titanium dioxide—can be classified as safe and effective. However, there are concerns about the endocrine-destructive effects of the other three ingredients: homosalate, avobenzone, and oxybenzone.
The European Commission considers the levels of two of them to be unsafe at the levels they are used in today's sunscreens. She therefore suggested limiting concentrations to 2,2% for oxybenzone and 1,4% for homosalate. At the same time, US sunscreen manufacturers are legally allowed to use these two chemicals in concentrations up to 6% and 15%.
Oxybenzone, octinoxate, octisalate, octocrylene, homosalate and avobenzone are absorbed into the body through the skin even after one use. Studies have shown that they can be detected in the skin, blood, urine and even breast milk a few weeks after stopping the use of the cream.
Such long-term exposure of the skin to the chemical constituents of sunscreen is a matter of concern. Especially because there is not enough data on their safety. Even more worrying is oxybenzone – multiple studies have shown that it leads to hormonal imbalances.
On the subject: The heat has begun in New York: how to properly protect the skin from the harmful effects of the sun
Scientific evidence on the toxicity of sunscreen ingredients
Oxybenzone (benzophenone-3 or BP-3)
It is the most troubling active ingredient in sunscreens. It is readily absorbed through the skin, and the Centers for Disease Control and Prevention has found it in nearly all Americans. Moreover, its level is noticeably higher in those who often use sunscreen. Oxybenzone often causes allergic skin reactions, but this is not the worst thing. Worst of all, it can disrupt hormonal balance and potentially pose more harm to children.
CDC researchers found that teenage boys with high blood levels of oxybenzone had significantly lower total testosterone levels. Three other studies showed a statistically significant association between oxybenzone exposure during pregnancy and birth outcomes. One of them found that if a woman is carrying a boy and she has a high level of oxybenzone, then the risk of preterm birth is significantly increased. Oxybenzone also results in high birth weight for boys and low birth weight for girls. Exposure to oxybenzone and related chemicals in women is associated with an increased risk of endometriosis.
Four studies published in 2020 support previous findings that oxybenzone may act as a hormone disruptor and increase the risk of breast cancer and endometriosis. In addition, the National Toxicology Program found that rats had increased thyroid tumors and uterine hyperplasia after exposure to high levels of oxybenzone.
Researchers at the University of California, Berkeley reported a dramatic drop in cosmetic exposure to oxybenzone in teenage girls when they switched from traditional products to replacements that did not contain the chemical.
Several countries ban the sale of oxybenzone sunscreens because it can be harmful to aquatic life.
Octinoxate (Octyl Methoxycinnamate)
Octinoxate is an organic UV filter. It absorbs easily into the skin and continues to absorb after sunscreen is applied. It has been found in the blood of frequent sunscreen users at levels 16 times the FDA's proposed safety threshold. Animal studies have shown that this chemical has a hormonal effect on the metabolic system and influences the production of thyroid hormones.
Sunscreens containing octinoxate are banned in some countries because they can be harmful to aquatic life.
Homosalat
Homosalate is an organic UV filter widely used in American sunscreens. The FDA said it did not have enough data to fully evaluate its safety and efficacy. Separate studies have found that homosalate penetrates the skin, disrupts hormones and produces toxic by-products of breakdown over time.
In Europe, homosalate can be used at a concentration of no more than 1,4% due to concerns about potential endocrine disruption. The FDA allows US sunscreen manufacturers to use it at concentrations up to 15%.
Octisalate
Octisalate is an organic UV filter. It is easily absorbed through the skin. The FDA considers that the acceptable level of this substance in the blood is 0,5 nanograms per milliliter. Americans who use sunscreen frequently have levels 10 times higher. This chemical is associated with allergic contact dermatitis, and octisalate can interfere with estrogen production.
On the subject: How clean is the water on New York beaches, and how to find out its quality
Octocrylene
Octocrylene is easily absorbed through the skin, but is not as dangerous as the substances listed above. Studies have shown that octocrylene causes skin allergies and, when dissolved in water, can harm the health of corals.
In addition, octocrylene is often contaminated with the carcinogen benzophenone (its level may increase during long-term storage). The European Commission concluded that, despite some evidence of the endocrine-destructive potential of octocrylene, concentrations up to 10% are considered safe.
Avobenzone
Avobenzone is a widely used organic filter that provides protection against UVA rays (95% of the UV rays reaching the Earth's surface).
Because avobenzone is unstable, it must be paired with other ingredients that act as stabilizers to prevent it from breaking down in the sun. The breakdown products of avobenzone can cause allergic reactions. Avobenzone can interfere with the endocrine system. And, as studies on cells have shown, it blocks the action of testosterone.
Final World
It happens that we find ourselves between two fires: ultraviolet - skin cancer; sunscreen - hormonal disruptions ... How to be?
It is necessary to protect yourself from ultraviolet radiation - most cases of skin cancer in humans are caused by exposure to ultraviolet radiation. Its main source is sunlight. About 95% of the UV rays that reach the earth are UVA, and the remaining 5% are UVB rays (the most dangerous). But you can protect yourself from them not only with a cream. Hats, caps, long sleeves also do an excellent job with this task. Well, if you are going to the beach or on a safari, then it makes sense to use sunscreen - do not leave your skin unprotected!