Octinoxate is a substance that shields the skin from harmful UVB rays. It is an ingredient in some cosmetic products, such as sunscreen. Another name for it is octyl-methoxycinnamate.

Scientists are unsure whether octinoxate could be harmful to humans. There is insufficient research to confirm its safety, but the few human studies that do exist suggest that it has a minimal effect.

However, scientists do know that octinoxate damages marine ecosystems. Water treatment plants cannot easily remove chemical sunscreens from the water, allowing octinoxate and similar substances to enter rivers and oceans. As a result, some authorities have chosen to ban sunscreens containing octinoxate.

In this article, we discuss octinoxate in more detail, including the products that can contain it, its safety, and its environmental impact. We also look at environmentally safe alternatives that still protect the skin from UV damage.

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Octinoxate is a type of chemical known as a cinnamate ester. Cinnamate esters are organic acids that occur naturally in certain foods, such as grapes.

Companies first began using octinoxate as a form of UV protection in the 1950s. It works by absorbing UVB rays from the sun. This is the type of UV light most associated with sunburn and skin cancer.

Manufacturers typically combine the octinoxate with other substances that prevent the skin from absorbing it. This minimizes the risk of octinoxate affecting someone’s health. However, the skin may still absorb a small amount.

Octinoxate is the UVB filter in 90% of sunscreens in the United States. The Food and Drug Administration (FDA) has approved it for use in cosmetic and pharmaceutical products.

Companies use octinoxate in products that require an SPF. These can include:

  • sunscreens
  • lip balms
  • hand or face moisturizers
  • makeup products
  • perfumes
  • hair sprays
  • aftershaves

People can find this ingredient on product labels under various names. Companies may list it as:

  • octinoxate
  • octyl-methoxycinnamate
  • 2-ethylhexyl-4-methoxycinnamate
  • avobenzone (Parsol, Escalol)
  • Neo Heliopan

Both the U.S. and European Union consider octinoxate safe in certain concentrations. The maximum concentration in ready-for-use products is 7.5% in the U.S. and 10% in the E.U.

Scientists classify octinoxate as an endocrine disrupting compound (EDC). EDCs affect the endocrine system, which is responsible for making and regulating hormones in the body.

However, despite the fact that small amounts of octinoxate can penetrate the skin barrier, its ability to do this appears to be limited, based on current evidence.

There is a lack of research on octinoxate, though, in comparison with other chemical UV filters.

Some laboratory and animal studies have shown that octinoxate has the potential to cause harm when the concentration is high enough.

However, scientists work with isolated cells or tissues in laboratory studies and use animal test subjects, such as rats, in animal studies.

The findings of this research can indicate a potential risk, but they do not always represent how a chemical might affect humans.

So far, no study has looked at how octinoxate exposure via sunscreens and other products affects humans over an extended period. There are also no studies on how octinoxate affects fetal development, according to a 2020 review.

The evidence that does exist suggests that octinoxate may:

  • Cause dermatitis: Some people are allergic or sensitive to octinoxate, which may result in allergic contact dermatitis. This type of eczema causes an itchy, inflamed rash in the area that comes into contact with the irritating substance. Another type of reaction is photo contact dermatitis, which occurs due to a combination of an allergen and UV light exposure.
  • Affect hormones: Octinoxate is an EDC, but its potential to affect human hormones is unclear. An older, short-term study from 2004 found that a cream containing octinoxate and other UV filters had little to no effect on hormones in males or females after 2 weeks. However, the study only involved 32 people.
  • Affect the nervous system: An older 2010 study on cells from rats found that octinoxate altered the release of important neurotransmitters, decreasing the levels of aspartate and glutamate. The doses of octinoxate were extremely high, though, and not comparable to the doses of octinoxate that people typically encounter.

More up-to-date and longitudinal research on octinoxate is necessary to give scientists a better understanding of any risks the substance may pose.

Chemical UV filters, such as octinoxate, have a harmful effect on marine ecosystems. They are present in almost all sources of water worldwide.

UV filters are a possible contributor to coral bleaching, which is when coral dies and turns white. This, in turn, can be detrimental to the entire ecosystems that coral reefs support.

Scientists have also identified UV filters in various species of fish around the world, with potentially serious implications for the food chain.

Octinoxate and other chemical UV filters are extremely difficult to remove using typical wastewater treatment techniques. For this reason, many people are opting for “reef safe” sunscreens and other SPF products.

In the U.S., some local and state authorities, including Key West, FL, and Hawaii, have banned the use of octinoxate. More recently, the Florida Keys and Miami Beach have proposed similar legislation.

People who wish to avoid octinoxate-containing products can do two things. Firstly, they can avoid products that contain octinoxate in cases where UV protection is unnecessary, such as in perfumes. Secondly, they can choose mineral-based sunscreens in situations where UV protection is necessary.

Mineral sunscreens contain titanium dioxide, zinc oxide, or a mixture of both. While chemical filters absorb UV rays, these minerals act as a shield, deflecting the rays away. This type of sunscreen is suitable for sensitive skin and does not have the same damaging effect on marine life.

When shopping for a new sunscreen, a person can look for the following on product labels:

  • broad-spectrum
  • 100% mineral sunscreen
  • reef safe

The American Academy of Dermatology Association recommends an SPF of 30 or more to protect against sun damage.

Mineral sunscreens are present in many of the same products as chemical sunscreens, including lotions, makeup, and lip balm. However, some can leave a white cast on the skin. People can avoid this by choosing a tinted sunscreen, moisturizer, or lip balm.

Octinoxate is a type of UV filter. It absorbs UVB rays from the sun, protecting skin from the damage these rays can cause. It is a common type of UV filter in the U.S. and appears in sunscreens, moisturizers, lip balms, and other products.

However, there are significant concerns that chemical UV filters are damaging marine life. They may be contributing to coral bleaching, which is having a devastating effect on coral reefs. Whether octinoxate harms human health is unclear due to a lack of extensive and high quality human studies.

For people who want an environmentally safe alternative, mineral sunscreens such as zinc oxide or titanium dioxide are available in many products. People can identify these products by reading the label and looking for reef safe options.

For more information on the environment and sustainability, please visit our dedicated hub.