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Alumier Skin Experts / January 11, 2019

Concerns with Chemical Sunscreen Filters

Most chemical sunscreen filters are made up of small particles that are absorbed into the skin.  Examples include oxybenzone, octinoxate, homosalate, octisalate and octocrylene. Some of these particles have even been found in plasma and urine [1]. By contrast, physical sunscreen ingredients like zinc oxide and titanium dioxide contain large particles that sit on the skin.

Dozens of studies in the last decade have examined the potential health hazards of sunscreen chemicals, including skin irritation or allergy, hormone disruption and skin damage that occurs when sunlight interacts with sunscreen chemicals (EWG: Environmental Working Group). Many of these sunscreen chemicals are known or suspected hormone disruptors, allergens and carcinogens.


Oxybenzone is part of the benzophenone family and EWG gives it a high hazard rating of 8/10. It penetrates the skin and has been found in mother’s milk. The U.S. Centres for Disease Control (CDC) detected oxybenzone in more than 97% of Americans based on a sample of more than 2500 adults and children [2].

Oxybenzone has been associated with skin allergies and is known to be a hormone disruptor. A study by the National Institute of Health (NIH) and the New York State Department of Health’s Wadsworth Centre found that men with high exposure to benzophenone UV filters had a 30% reduction in fertility [3].

A study by researchers at UC Berkeley and Clinica de Salud del Valle Salinas has demonstrated how taking a 3-day break from various cosmetics can lead to a substantial drop in levels of hormone-disrupting chemicals in the body. Oxybenzone fell by 36% and methyl/propyl parabens dropped by 44-45% [4].

Oxybenzone is also an emerging marine contaminant that poses a hazard to coral reef conservation [5]. On May 1, 2018, Hawaii became the first state to pass a bill banning the sale of sunscreens containing oxybenzone and octinoxate that scientists have found contribute to coral bleaching when washed off in the ocean. Pending the governor’s signature, the new rule will go into effect on January 1, 2021 [6].


Octinoxate is another small molecule chemical UV filter that has been given a hazard score of 6 by the EWG due to high concerns of biochemical or cellular level changes and endocrine disruption (EWG).

Octinoxate can be absorbed quickly through the skin and has been detected in urine, blood and breast milk [7,8]. It is an endocrine disruptor that mimics estrogen and can disrupt thyroid function.

Lifetime estrogen exposure is a risk factor for developing certain types of cancers in women, including breast cancer. In an article published in Environmental Health Perspectives, octinoxate was shown to increase cell proliferation in breast cancer cells [9]. Octinoxate may also have thyroid-disrupting properties [10]. The thyroid gland is part of the body’s metabolism system.

A reduction of sperm count has also been shown in offspring of those who were exposed to octinoxate [7]. In addition, results of the Danish study presented at the Endocrine Society’s 98th annual meeting in Boston in 2016 showed that the following UV filters disrupt sperm cell function: avobenzone, homosalate, meradimate, octisalate, octinoxate, octocrylene, oxybenzone, and padimate O. These chemicals are common ingredients in sunscreens.



Photostability is a term that describes how slowly (or quickly) the UV protection of a sunscreen filter or product will break down due to exposure to UV radiation. Sunscreen filters fall into two classes, physical and chemical.

Physical filters (zinc oxide and titanium dioxide) are the most stable and maintain their ability to filter UV rays even when they are exposed to these rays. Physical filters sit on top of the skin and reflect and scatter most UV radiation rather than absorbing it, thereby remaining intact.

Chemical filters (octinoxate, oxybenzone, avobenzone, homosalate, octocrylene, octisalate) penetrate into the skin and absorb most UV radiation, converting it to heat energy. Chemical filters are changed by UV radiation in this process. Not only does the UV protection they provide decrease but their chemical composition also changes releasing free radicals as a result. This is one of the reasons for the suggestion that some chemical sunscreens may actually cause cancer. Free radicals also cause premature aging.

Health Canada, the FDA and several medical associations maintain that these chemical filters are safe only because there are no randomized clinical trials proving otherwise, not because they have actually been proven to be safe. We should be proactive and avoid these filters. There will never be double-blinded randomized clinical trials regarding the above because they would be unethical.

**AlumierMD’s sunscreens do not contain small molecule chemical filters.


  1. Janjua MR, Kongshoj B et al. Sunscreens in human plasma and urine after repeated whole-body topical application. Journal of the European Academy of Dermatology and Venereology 2008;22(4):456-61.
  1. Calafat AM, Wong LY et al. Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey. Environ Health Perspect 2003-2004;116(7):893-7.
  1. Germaine MBL, Kurunthachalan K et al. (2014). Urinary concentrations of Benzophenone type ultraviolet radiation filters and couples’ fecundity. American Journal of Epidemiology 2014;180(12):1168-75.
  1. Published in Environmental Health Perspectives Link to mention: http://www.collective-evolution. com/2016/04/06/what-happens-to-your- skin-when-you-switch-to-cosmetics-with-less-chemicals/
  1. Downs CA, Kmarsky-Winter E et al. Toxicopathological effects of the sunscreen UV filter, Oxybenzone (Benzophenone-3) on coral planulae and cultured primary cells and its environmental contaminants in Hawaii and the US Virgin Islands. Archives of Environmental Contamination and Toxicology 2016 Feb;70(2):265-88.
  1. Elaine Glusac, The New York Times, May 3, 2018.
  1. Axelstad M, Boberg J et al. Effects of pre-and postnatal exposure to the UV-filter Octyl Methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring. Toxicol Appl Pharmacol 2011 Feb;250(3):278-90.
  1. Darbre PD. Environmental oestrogens, cosmetics and breast cancer. Best practice & research clinical endocrinology & metabolism 2006;20(1):121-43.
  1. Schlumpf M, Cotton B et al. In vitro and in vivo estrogenicity of UV screens. Environmental health perspectives 2001;109(3):239.
  1. Boas M, Feldt-Rasmussen U & Main KM. Thyroid effects of endocrine disrupting chemicals. Molecular and Cellular Endocrinology 2012;355(2):240-48.

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