I have said for over a decade, just about every day, that most sunscreens are neither SAFE nor EFFECTIVE. My “undesirables”  singled out for strict avoidance were avobenzone, oxybenzone, homosalate, octisalate, octocrylene, 4-methyl-benzylidine camphor, and regular (non-encapsulated) octinoxate,  present in most brand name, drug store, or doctor dispensed sunscreens. I cautioned that consumers should avoid these soluble Polycyclic Aromatic Hydrocarbon (PAH) sunscreen filters that enter blood and tissue through the skin, and are implicated as hormone disruptors and carcinogens that mutate DNA. Most parents and pregnant women are unaware of these established facts.

The FDA now agrees with me. Zinc oxide and titanium dioxide are the only two UV filters proposed to receive a Category 1 or GRASE (Generally Regarded As Safe and Effective) designation.  The FDA has placed  virtually all the PAH  filters used in typical brand name sunscreens on a “watch” list – insufficient data to support a positive GRASE  label – safety and efficacy need  to be established – to be known as Category III. These include cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone or avobenzone at this time.

While the statutory process is underway, it is very clear is that the prevailing scientific evidence led the FDA to declare that the 12 filters above, including my 7 undesirable, cannot now be considered as  safe and effective. In 2008 the Centre for Disease Control confirmed that oxybenzone, the most popular UV filter at the time, was found in 96.8 % of Americans, both genders, ages 6-70. Other studies confirmed that 85.2% of nursing mothers had one or more UV filters in breast milk, and 99% of patients having amniocentesis in the 3rd trimester had oxybenzone in amniotic fluid. The golden rule in endocrinology is “isoform function”, same structure – same actions – where permeation and hormone disruption are concerned. For two decades, I have said that if oxybenzone reaches blood, all PAH filters will do so at different rates, and take varying times to attain steady state and peak levels. The FDA did their own permeation and bioavailability studies, which confirm that all in the group (including avobenzone) attain blood levels. This led to their new proposals when they also decided that the sunscreen issue was very similar to that of BPA. I still ask  – why is there not a WARNING label on permeation and a CAUTION to pregnant women, as there is for anything sold in a pharmacy with the potential to reach the unborn.

It is still not clear whether a regulatory framework will emerge that is easy for the consumer to understand and actually leads to safe and effective sunscreens. The new generation of sunscreens must have the ultra UVA protection that contemporary science proves is necessary to prevent skin cancer and photoaging. The FDA finally accepts that better methods are needed to confirm the UVA protection afforded by a sunscreen and a BROAD SPECTRUM claim. They also discuss for the first time that many of the PAH filters like oxybenzone may be estrogenic or act as Endocrine Disrupting Chemicals (EDC), which can adversely affect human and wildlife health. They act by hormone disruption of reproductive and other endocrine systems.

The industrial alliance still argue that there is no real evidence of hormone disruption in humans.  Many physicians must not read Endocrine and human or Ecotoxicology  literature.   This literature is replete with evidence of diverse hormone disruption in humans and wildlife over the past 20 years.  A recent statement from an Australian/New Zealand Policy Group again repeated the old and inaccurate claim based on outdated studies in rodents and humans. Humans are not large rodents and endocrine receptor function in humans is unique.  A 2016 review of 85 scientific papers in humans and lower species concluded that aromatic hydrocarbon UV filters are generally involved in the disruption of the hypothalamic–pituitary–gonadal system.  More recent studies in 2018 confirm that UV hydrocarbon filters, other phenols including the preservative parabens, clearly change levels of virtually every sex hormone, pituitary hormones, thyroid hormones and certain growth factors in both pregnant and non-pregnant women. A change in a hormone level is evidence of HORMONE DISRUPTION. The numerous clinical consequences are  another matter, and may not be evident for up to 40 years or more. A 2019 publication showed evidence that the PAH UV filters can affect the timing of puberty in boys and girls. Physicians must remember the first precept or sacred trust in medicine “first do no harm”. Our regulators, policymakers, and legislators must apply the Precautionary Principle.

UV hydrocarbon filters clearly permeate into your blood and attain various levels –  reason enough to avoid them. They belong to a group of 1000 plus hormone disruptors, for which the WHO and The Endocrine Society provide scientific data showing the strong evidence for links to adverse effects in humans. These include female reproductive disorders (infertility, uterine fibroids, endometriosis, PCOS), male infertility,  reproductive cancers (uterine, breast cancer, and prostate), thyroid cancer, Hirschsprung’s disease and hypospadias in the newborn, childhood disorders (asthma, ADHD, and autism), neurodegenerative problems (Parkinson’s and Alzheimer’s disease), and metabolic disorders- obesity and type 2 diabetes.

sunscreens, endocrine disrupting chemicals
The Effect of Sunscreen Actives on Human Health at Various Stages of Development

Prudent people, especially nursing and expectant mothers, parents of young or adolescent children, and couples trying to conceive will mostly agree with our philosophy as physicians and that of the Sunscreen Companyhttps://thesunscreencompany.com/   to apply the Precautionary Principle – err on the side of caution – and the sacred trust in  medicine – first do no harm. 

It may take awhile for a sensible set of rules and enforcement to emerge and be validated by the test of time. This will become evident when the new ultra UVA sunscreens consistently prevent sunburn and   begin to lower N. American skin cancer rates for the first time. In the meantime one easy approach to use in everyday life is as follows:


  • Practice sun avoidance as much as you can. The usual caution to stay out of the sun between 10 am to 2pm is more a way of lowering your UVB exposure as UVA does not vary much with time of day or latitude. Modern science suggests that UVA is the main driver of skin cancer and photoaging. Use an ultra UVA sunscreen which will also have high UVB protection. High UVB or high SPF sunscreens may have little  UVA protection even when labelled as BROAD SPECTRUM. The new rule proposed by the FDA that UVA has to be measured not inferred and that the ratio of UVA1/UV protection has to be > 0.70 are similar  to existing EU and Australian requirements.
  • Wear sun/UVR protective clothing when outdoors and cover as much skin as you can. It is a very efficient way of providing broad spectrum protection and it reduces the amount of sunscreen you use each day. Dermatologist Sharyn Laughlin uses Solumbra™ for outdoor or vacation sun exposure – it is a tried and trusted brand of UV protective textiles. Wear a hat with a 3-5” brim and use UV protective sunglasses to shield your eyes.


  • Use SPF 25-50 but bear in mind that most sunscreens have a Real Life SPF in sunlight of 10-15 even if labelled at 50 or more. Reason – the lamp used for the SPF test emits light in a spectrum bearing no resemblance to actual sunlight. Real sunlight has 5X more UVA than the lamp. If you are very fair, assume that the SPF in popular brands may be actually only 10, and adjust your exposure time accordingly. If your unprotected skin burns in 5 minutes, only stay out for 5 times 10 = 50 minutes, and not use 30 or 50 as the multiplier for safe exposure time. The particle sunscreens with zinc oxide from https://thesunscreencompany.com/ do achieve Real Life SPF  closer to their label values because of the special nature of the dispersion using proprietary technology.
  • A Broad Spectrum label as regulated in Canada and the USA is likely to be untrue. Zinc oxide and avobenzone are the two common UVA filters used. 3% avobenzone or < 14% zinc oxide will only achieve a UVA-Protection Factor (UVA-PF), measured by a valid method of 5-8 – not adequate for any real prevention of skin cancer or photoaging. Avobenzone is unstable and forms nasty complexes with chlorine. I consider it an “undesirable” like its structural cousin oxybenzone. Both are now on the proposed FDA watch list. Mexoryl SX™ and XL™ are patented to L’Oreal and are good broad spectrum filters but they are always mixed with undesirables on the FDA watch list.
  • Visit https://thesunscreencompany.com/ for unique ultra UVA zinc oxide sunscreens with patent pending biodegradable dispersing agents that give our sunscreens better Real Life SPF and the best UVA protection in N. America. Our 25 % zinc oxide Simply Zinc Ultra (SZU) affords unmatched UVA protection for everyday as a makeup base or for outdoor and any vacation exposure. Ultra UVA protection is able to prevent the UVA damage that drives cancer. SZU achieves the highest UVA-PF of 20.4 compared with the 5 to 8 or less of virtually all the brands available in N. America. We advise all  Canadians to apply a high UVA sunscreen everyday to face, neck and back of your hands or any other exposed areas, every day in every season. A computer derivation shows that if you use a sunscreen with this level of UVA protection daily from a young age, when you are 70 years old you may look like you are only age 45. Daily application of a sunscreen like SZU is a good way to reduce your need for rejuvenation procedures, and to protect your investment after facial rejuvenation (subject for my next blog). Melanoma occurs more commonly  in white Americans and Europeans that work indoors and assume they do not need a sunscreen. For most of us, 65% of lifetime UV radiation is ambient, and not from outdoor or vacation exposure

Harm to human health and the environment, particularly the coral and marine habitat, occurs through the same pathway – first permeation then hormone disruption and DNA mutation. Visit my blog https://thesunscreendoc.wordpress.com/2019/02/14/your-march-break-vacation-endangers-the-marine-ecosystem/ . Given the human and environmental harm from typical brand name sunscreens – there is a serious irony present. We use sunscreens to prevent cancer –  the undesirable filters give UVB-BIASED protection that cannot prevent skin cancer. They apparently do not, as global rates have doubled since 1960, despite the increasing use of these sunscreens.

Adult exposure to an EDC may have different consequences from fetal or infantile exposure. Endocrinologists use the term “the developmental basis of adult disease”, where  developing organisms – the fetus (eutherian mammals), the egg (other vertebrates), and the external environment (such as EDC exposure), interact with an individual’s genes to determine later onset of disease. The latent period may be considerable – the disease may not be apparent early in life but may only become evident  in adulthood or senescence.

Since 1991, I have cautioned that UV filters with a benzene ring resembling DDT, petroleum and other phenols, which have  estrogenic and other hormone actions – however minimal – cannot be regarded as safe for anyone.  It took the FDA over 20 years to agree with me.  Better late than never.

© Denis K. Dudley MD, FEB 2019. All rights reserved.



The ‘Winter blues’ drives 50% of Canadians towards a beach vacation and  March Break accounts for a major part of the over 85.8 million days spent by beaches (2017 Expedia® Flip Flop Report). The R&R benefit and the break from routine are positive. Most  Canadians are unaware that they contribute to coral degradation on a global scale caused by toxicity to coral and marine organisms from Polycyclic Aromatic Hydrocarbon (PAH) UV filters found  in 90% of sunscreens they use.  The world’s third-ever global coral bleaching event is now underway (NOAA). From Hawaii to the iconic Great Barrier Reef, eastward all the way to the Bahamas, Caribbean, coastal Central America and beyond — coral reefs are now being severely damaged or even dying. Coral degradation from sunscreen toxicity is  a major factor in this devastation to the coral and marine wildlife. Effects occur within a short time frame unlike the slower pace of changes induced by a rise in ocean temperatures from climate change. Coral bleaching accelerates and worsens climate change damage and devastates coral recruitment all around the world. The undesirable UV filters are genotoxic to coral larva, which greatly lowers reef generation and coral resiliency to climate change.

The common pathway for toxicity to humans and the marine eco-system.

coral bleaching, reef safe sunscreen
Living Coral vs. Dead Coral- the visible effect of coral bleaching
  • First PERMEATION then HORMONE DISRUPTION, DNA mutation and genotoxicity. Coral has an epidermis similar to but less complex than human skin. The PAH UV filters used in over 80% of our sunscreens permeate human skin to varying degrees and attain blood and tissue levels. These include avobenzone, oxybenzone, homosalate, octisalate, octocrylene, unencapsulated octinoxate, and 4-methyl benzylidene camphor (4-MBC). Studies confirm their presence in human blood, amniotic fluid, urine and breast milk.  Human contamination is not in dispute, yet Industry and most physicians (including dermatologists) ignore or deny this fact.
  • Only avobenzone has any UVA1 filtering and all the others provide UVB and some UVA2 protection. Combinations of these filters, even with 3% avobenzone as a UVA1 filter, give inadequate protection. They filter UVB to UVA in an extreme BIAS of up to 10 to 1 or more. UVB-BIASED sunscreens dominate the global sunscreen market. They prevent UVB effects like sunburn to varying degrees but cannot prevent skin cancer and photoaging to any significant degree. The unrelenting rise in global skin cancer rates support this assertion. Modern science shows that the long wave UVA1 rays are the primary drivers of skin cancer and sun damage.
  • These ineffective sunscreens  contaminate our bodies and the oceans. Numerous studies confirm their links to serious human disorders- from infertility in both sexes, uterine, breast, prostate and thyroid cancers, autism, ADHD, Parkinson’s and Alzheimer’s diseases, obesity, 5% of adult Diabetes, and  perhaps 1/3 of all cases of endometriosis and uterine fibroids in women.
  • Oxybenzone is contaminating marine environments – washing off swimmers to municipal, residential, and  the wastewater effluent from marine vessels. A 2015 report (Downs et al) confirms other studies that oxybenzone is genotoxic, kills larvae of reproducing coral, and converts the planula from a motile to a sessile state by ossification, acting as a skeletal hormone disruptor. Coral reef contamination of oxybenzone in the U.S. Virgin Islands ranged from 75 μg/L to 1.4 mg/L, whereas Hawaiian sites were contaminated between 0.8 and 19.2 μg/L. Concentrations of oxybenzone and homosalate in Japanese waters ranged from 0.5-1340 ng/L and 0.5-214 ng/L respectively. Finally, concentrations of oxybenzone and avobenzone in South Carolina waters ranged from 37.6 – 591 ng/L and 31.9 – 234 ng/L.
  • This persuasive science led to the ban of some of these toxic filters in Hawaii, Palau, and Key West. The entire group needs to be avoided in humans, if only by virtue of their permeation. The risk of permeation should a label warning on PAH sunscreens, particularly in pregnancy and for young children- just the same way there is for alcohol and cigarettes. The health risks of these estrogenic benzene compounds to all of us are considerable. They outweigh risks of BPA (bisphenyl A) banned in some countries by applying the Precautionary Principle. This precautionary and sensible approach is consistent with the first dictum in medicine – primum non nocere – first do no harm. Neither are being applied where these toxic UV filters are concerned. Label warnings of entry to our bodies might convince prudent parents to avoid them and greatly decrease their use. This would also protect the coral.
  • Numerous studies have identified significant stress responses and mortality in scleractinian corals exposed to relatively low concentrations of these chemicals, even parts per billion All will potentially permeate and harm the coral. I have been invited to join a research team at Halmos Laboratory of Natural Sciences and Oceanography (Nova Southeastern University) to study the whether avobenzone and homosalate have the same deleterious effects on our oceans as oxybenzone. It is highly probable that they will.

The Human Tragedy and Economic Consequences

There is no way to calculate the human tragedy when infertility and other endocrine disorders occur from hormone disruption caused by UV filters, even if the risk is low. In humans they represent a primary exposure to hormone disruptors in a first world modern society – now more likely than DDT, dioxin, BPA, and others. Diseases related to all hormone disruptors cost the US health care system 360 billion dollars (2014). The economic costs of destroying coral and marine wildlife are even more enormous.

  • It is estimated that 15-20,000 tons of hydrocarbon sunscreens wash off annually and destroy our reefs, similar to the way an oil spill would. Oil spills are episodic events, sunscreen slicks are daily and worldwide. The sunscreen slick can damage reefs 6-10 miles offshore.
  • 1,200 square miles of coral reefs in the United States generate more than a billion dollars per year in related benefits and business. Areas with more reef area like Southeast Asia, benefits annually from corals at 12.5 billion. Coral reefs acting as the sentinel organism in the marine ecosystem provide 8 trillion USD of economic benefits to humans.
  • The Caribbean has lost 80% of its reefs in the past 50 years mostly before 1991 and paralleled the growth of mass tourism and mega cruise ships. Reef systems in the Bahamas are showing the slow deterioration in  coral and marine wildlife over the past 30 years, not due to oil spills in the Gulf as suggested by the government. The loop current would take the contamination up the east coast of Florida. The more likely answer is the large amounts of these toxic sunscreen hydrocarbons being deposited in the coastal waters of the Bahamas by the millions of visitors in resorts and cruise ships. Resorts in Thailand (Maya Beach), the Philippines (Borocay Bay) and in Indonesia have had to shut down beaches and close hotels, because of dead coral reefs. Thoughtless mass tourism damages the local environment. Once the coral dies, the marine life leaves, and the white sand beaches disappear. Then the tourists no longer visit.

The Ironic Paradox

Sunscreens are meant to prevent skin cancer. UVB-BIASED sunscreens using soluble polycyclic aromatic hydrocarbon (PAH) filters clearly may not. Rising global skin cancer rates support this view. The global rise   parallels  the dominance of UVB-BIASED sunscreens. So these sunscreens with PAH filters pollute our bodies and the oceans and may actually be a factor in rising cancer rates.

  • Skin cancer accounts for > 50 % of all cancers in N. America – more than all others combined.  Melanoma rates in the USA tripled between 1975 – 2014, now  the leading cause of cancer death in women ages 15-30, the second leading cause of cancer death in women ages 30-35, and the second most commonly diagnosed cancer age 15-29. One person dies of melanoma every 54 minutes in N. America.
  • Global skin cancer rates rose at 3-8 % annually (The Global Burden of Disease Study 2015) It also reported that in the prior 10 years, there was a 27.2% and 42.9% increase in the global death rate from melanoma and NMSC respectively.
  • UVB-BIASED sunscreens lack the UVA protection required to prevent skin cancer and photoaging. Mineral sunscreens with zinc oxide in high concentrations, alone or combined with titanium dioxide, do not permeate human skin, avoids all the controversial effects in humans, gives better broad spectrum protection against UVA1, and is very likely  better for the land based and marine environment.
  • Most of the PAH filters and some of the undesirable preservatives used with them represent the leading causes of allergic contact dermatitis or photocontact allergy , if the reaction is precipitated by sunlight. This affects only a few individuals but it is IRONIC that most dermatologists still recommend the use of UVB-BIASED sunscreens, even if you discount the permeation and hormone disruption in humans and coral. Zinc oxide cannot cause this type of allergy, an additional advantage to its better protection and safety.

The Simple Solution

The persuasive evidence of sunscreen toxicity to coral led Hawaii in March of 2018 to ban oxybenzone, and unencapsulated octinoxate – effectively eliminating 90% of the sunscreens Canadians use at home and abroad. Palau in the Pacific Rim instituted a wider ban in November 2018 on  oxybenzone, octinoxate, 4-MBC, octocrylene, 4 kinds of parabens, triclosan, and phenoxyethanol.  Key West followed Hawaii and just approved a ban on oxybenzone and octinoxate.  A ban on ineffective sunscreens that are also toxic to humans and the environment is “low-hanging fruit”. It requires no large capital expenditure  on anyone’s part – unlike other initiatives to tackle global warming. If you stop wearing sunscreens with soluble filters like benzophenone and spread the word on social media, there would be an enormous benefit to human health. This action is a win-win. It preserves human reproductive and metabolic health – saving billions in unseen health care costs. Using mineral sunscreens can actually prevent skin cancer and photoaging. It simultaneously preserves the sanctity of our oceans, as a sanctuary for marine wildlife and a key player in the global food supply, global economics, a livelihood for millions, coastal protection, fisheries, tourism, recreation and biodiversity. 

HUMAN and REEF safe sunscreens are hard to find in resorts of the Caribbean, the Bahamas and S. Florida.

Governments and the tourism industry should lead in this important initiative.  I have approached Government ministers and resort owners in island nations and provided the scientific evidence for human concerns and pointed them to the Downs study. The silence is deafening!  The ordinary citizen can show the leadership. Make an informed choice on your March Break holiday. Avoid sunscreens that  enter your child’s body, are unlikely to prevent sunburn and skin cancer, are a primary source of exposure  to hormone disruptors, and harm the land based and marine environment. Just the fact that these benzene compounds enter blood and tissue should give you pause. Change to a mineral sunscreen – zinc oxide with or without titanium dioxide. Clear or transparent zinc oxide sunscreens using 15-25 % concentrations provide the best safe and effective broad spectrum protection. Those with < 15% are safe but do not provide adequate UVA protection to be optimally effective against skin cancer and photoaging. Our Simply Zinc Ultra, the only 25% zinc oxide dispersion available is the most protective mineral sunscreen anywhere  www.thesunscreencompany.com .      

A cautionary word. Unscrupulous sunscreen companies are already using the ban on some UV filters to their advantage and deceptively market products as “Hawaiian Reef Friendly” or “Reef Safe”. If they contain any of the toxic six PAH filters – avobenzone, oxybenzone, homosalate, octisalate, octocrylene, unencapsulated octinoxate, and 4-MBC – they are not likely human or reef safe and should be avoided. They are likely to be absorbed at a faster rate by coral than they do through human skin, even that of your children. The NSU research is looking into the question of whether their similar hormone disruption in humans also extends to coral. It is more likely than not that they will act like oxybenzone and ossify the coral planula.

The industry and their dermatology partners have already started a publicity campaign to discredit the science on coral and marine wildlife toxicity, or to minimize and dismiss its significance. To them I pose this question. In the case of oxybenzone    can they name one other drug, OTC medication, pesticide, or contaminant that is present in 97% of people tested, in breast milk, amniotic fluid, and now being found widely in our rivers, lakes, oceans and municipal or cruise ship waste water? The enormity of this seems to be lost on the dermatology/industry alliance. Most politicians or hotel resort executive in the Caribbean and island nations actually pay lip service to reef conservation, and their inaction enables the environmental disaster. When the reefs die, it damages  their tourist based economies. The harm to their marine based food supply and livelihood of their citizens is inestimable.  The solution is so simple. Each of us can do this. Take a precautionary and prudent approach where the health of your family is concerned and conserve the health of our oceans at the same time. Wear UV protective clothing (like SolumbraTM) in the water. Sharyn Laughlin – dermatologist has been wearing these proven UV protective garments – she never goes south without them. Covering most of your body with UV protective clothing reduces the amount of sunscreen you use. Wear a mineral sunscreen. Both measures will be very effective reef and marine conservation. All that is required is the courage to act decisively.  Time is of the essence. Coral may be the canary in the proverbial coal mine.  It takes weeks to months for coral to die and up to 40 years or more for effects to be seen in humans.  

© Denis K. Dudley MD, FEB 2019. All rights reserved.