The risk of human toxicity for any xenobiotic begins with bioavailability from percutaneous absorption and with placental transfer to the fetus, the most vulnerable human. The FDA confirmed that 12 Soluble Organic UV Filters (SOUVF) used in sunscreens are all bioavailable to every human.
Benefit Risk Assessment (BRA) is the cornerstone of clinical medicine, public health, cosmesis and life in general, yet it was never done until recently for sunscreens.1 Label claims are largely based on the assumption that sunscreens prevent sunburn and by extrapolation skin cancer, but this was never validated by the necessary research trials looking at the BRA equation versus adverse effects.
The scientific literature persuasively establishes that 12 SOUVF are neither safe nor effective. The FDA affirmed in February of 2019 that 12 petrochemical UV filters lack evidence to be considered Generally Regarded As Safe or Effective (GRASE), and in September of 2021 denoted them as “Marketed Unapproved Drugs.”2 These petrochemicals include avobenzone (the solitary UVA1 filter), oxybenzone, homosalate, octisalate, octocrylene, octinoxate and six others. Some of these ingredients have been used in sunscreens and cosmetics for more than 50 years. The FDA also confirmed in 25 years of published science that SOUVF permeate skin and are bioavailable to humans.3 They designated two Insoluble Inorganic (mineral) UV Filters as GRASE.2
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It is advisable that every person stringently avoid SOUVF sunscreens, based on a BRA equation showing virtually no benefits and only risks. They are absolutely contraindicated in couples trying to conceive and during pregnancy. A few dermatologists recently admitted that only mineral sunscreens should be used by women of childbearing age and who are pregnant.4
Studies spanning over 25 years confirm warnings about the human danger posed by cutaneous absorption of oxybenzone from sunscreens.5 Basic physiology instructs that topical substances with a molecular weight (MW) less than 500 Daltons (G/mol) will enter human blood.6 All 12 SOUVF have a MW of less than 300 Daltons and their lipophilic nature ensures cell contamination of humans, including those in the brain and fetus. Insoluble UV filters, including zinc oxide, titanium dioxide, bemotrizinol and bisoctrisole are hundreds to thousand times larger than the threshold for percutaneous absorption, and are never bioavailable through intact human skin.1
Denis K.L. Dudley, MD is a board certified specialist in obstetrics and gynaecology in Canada, Great Britain and the U.S. He is the president of CyberDerm Laboratories and co-founder of The Sunscreen Company, which is dedicatd to the safety first approach for sunscreens and cosmeceuticals. Dr. Dudley has published 70 abstracts and papers and has won two awards from the University of Ottawa. www.thesunscreencompany.com
Sharyn A. Laughlin, MD, has her BSc in biology and has a Gold Medal in General Surgery. She is also a co-founder of The Sunscreen Company, and she is an assitant professor in the Division of Dermatology at the University of Ottawa. She started the first Canadian Fellowship Program for dermatologists in Cutaneous Laser Medicine & Surgery in 2000.