According to a June 2014 article featured in The Independent (UK), a major study conducted by researchers at the Karolinska Institute in Sweden found that women who avoid sunbathing during the summer are twice as likely to die as those who sunbathe every day.
The epidemiological study followed 30,000 women for over 20 years and “showed that mortality was about double in women who avoided sun exposure compared to the highest exposure group.”
Researchers concluded that the conventional dogma, which advice avoiding the sun at all costs and slathering on sunscreen to minimize sun exposure, is doing more harm than actual good.
That’s because overall sun avoidance combined with wearing sunscreen effectively blocks the body’s ability to produce vitamin D3 from the sun’s UVB rays, which is by far the best form of vitamin D.
In the USA, vitamin D deficiency is at epidemic levels. Ironically, vitamin D deficiency can lead to aggressive forms of skin cancer. A ground-breaking 2011 study published in Cancer Prevention Research suggests that optimal blood levels of vitamin D offer protection against sunburn and skin cancer.
Additionally, vitamin D protects the body from diseases like multiple sclerosis, rickets (in the young), tuberculosis, inflammatory bowel disease, type 1 diabetes, inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus and Sjogren’s syndrome.
According to the Vitamin D Council, researchers at the University of Alabama at Birmingham recently reported that “lack of sun exposure may lead to cognitive decline over time.”
A dissident dermatologist
Bernard Ackerman, MD, (deceased 2008) was one of the world’s foremost authorities on the subject of skin cancer and the sun, sunscreens and melanoma skin cancer risks.
Below are Ackerman’s views excerpted from an article in The New York Times (July 20, 2004), titled “I BEG TO DIFFER; A Dermatologist Who’s Not Afraid to Sit on the Beach”:
The link between melanoma and sun exposure (dermatology’s dogma) is unproven.There’s no conclusive evidence that sunburns lead to cancer.There is no real proof that sunscreens protect against melanoma.There’s no proof that increased exposure to the sun increases the risk of melanoma.
A 2000 Swedish study concluded that higher rates of melanoma occurred in those who used sunscreen versus those who did not.
SUNSCREENS: CANCER-CAUSING BIOHAZARDS
Elizabeth Plourde, Ph.D., is a California-based scientist who authored the book Sunscreens – Biohazard: Treat as Hazardous Waste, which extensively documents the serious life-threatening dangers of sunscreens not only to people but to the environment as well.
Dr. Plourde provides proof that malignant melanoma and all other skin cancers increased significantly with ubiquitous sunscreen use over a 30-year period. She emphasizes that many sunscreens contain chemicals that are known carcinogens and endocrine-disrupting chemicals (EDC).
Environmentally, she notes: “In areas where there have been much exposure to ED [endocrine disrupting] chemicals, coral and other sea populations have died off and the prevalence of dual-sexed fish has risen.”
Dr. Plourde’s research on mice and sunscreen exposure also showed increases in both pup and maternal mortality as well as reproductive issues in subsequent generations.
Additionally, the book documents how sunscreen chemicals have polluted our water sources including oceans, rivers and municipal drinking water. Worse yet, testing revealed that 97% of Americans have sunscreen chemicals in their blood!
Dr. Plourde’s book also has a chapter on the importance of vitamin D3 to health, and she posits that the widespread vitamin D3 deficiency is linked to overuse of sunscreen combined with sun avoidance in general.
Some sunscreens contain ingredients that might even trigger skin tumors and lesions, according to the EWG’s 2010 Sunscreen Guide.
The EWG recommends just 39 (8%) of 500 beach and sports sunscreens tested for the guide. Why do so many sunscreens get a mark of disapproval? A number of reasons–SPF claims above 50 can’t be substantiated; the FDA believes that a form of vitamin A called retinyl palmitate, found in 41% of sunscreens, could speed up skin damage and increase skin cancer risk when applied to the face, arms, legs, back, and chest; and many sunscreens contain oxybenzone, a hormone-disrupting compound that enters the bloodstream through the skin.
This is partially the fault of the FDA, which has promised–and failed to deliver on–regulations for sunscreen. The organization claims that regulations might be issued as soon as next October, but manufacturers will have at least a year to comply. In the meantime, which sunscreens can we trust?
The EWG’s top picks include Badger Sunscreen Face Stick, Purple Praire Botanicals Sun Stick, California Baby Sunblock Stick, and All Terrain Aquasport Performance Sunscreen. The biggest offenders–all of which contain Vitamin A and oxybenzone–include Rx Suncare Sports Sunblock, Rocky Mountain Sunscreen High Exposure, and philosophy shelter broad spectrum sunscreen for face and body. The full rankings are available here.
When I was in my late teens/early 20‘s I used to work at a pharmacy in the dispensing area. As part of theexperience, I had the opportunity to attend various workshops and seminars related to health from time to time. One particular time I was sent to a workshop about sunscreen products. I remember hearing everything that was shared and how sunscreen products must be recommended and taken seriously to protect everyone from skin cancer. I also remember thinking that something about this just did not make sense. The room was full of various white cream, chemical testers and myscience-loving mind and background was in full swing thinking about the reaction between these chemicals on the skin and the sun.
Fast forward to today and we have a population deficient in vitamin D, skin cancer is on the rise, continuing to plague more people each year, and the sunscreen industry is booming. According to the Skin Cancer Foundation, each year there are more new cases of skin cancer than the combined incidence of cancers of the breast, prostate, lung, and colon.
So what is going on? While I continue to still wonder about this myself, I have been actively trying to help people see the other side of the sunscreen story for several years now. After all, if we knew (at least) since the 1970‘s about the sun and skin cancer risk, shouldn’t all this sunscreen use start turning things around? Through continued research over the years, I have discovered some interesting theories and facts that I believe to be more true, than what we are told through the mainstream media and medical field about the need for sunscreen.
Connecting the Dots on Skin Cancer and Sunscreen Use
There are many things that we may not be sure of, at least not for some time, where the whole sunscreen and skin cancer trends are concerned. What we are sure of is that skin cancer rates are definitely on the rise. If you examine the graph below, you can see that since the 1970’s skin cancer rates for some parts of our population have more than quadrupled.
Prudent mainstream medical professionals will take one look at that graph and conclude that we must protect ourselves with more sunscreen any time we expose ourselves to the sun. I mean it looks obvious that the more skin cancer cases there are, the more likely we are to get it, unless we protect ourselves. Right? Well not so fast. While the sunscreen industry would love us to use more and in fact they don’t make this a secret, telling us to keep re-applying frequently and wear SPF protection year round as they put SPF ingredients into more and more everyday personal care products, there is much more to this story.
Commercial sunscreens, pretty much as we know them today, began their production and entry onto the market around the 1950’s and 60’s. Even though their use continued to increase from there, it wasn’t until about the 1990’s that sunscreen became very popular infiltrating every area of personal care products. At this point they were being widely marketed and available throughout North America, being touted as a “must” when we are outdoors, especially when in the direct vicinity of the sun.
So let’s consider our first idea. By the looks of those dates, one can begin to start connecting a possible correlation between the increased use of sunscreen and the increased presence of skin cancer. After all, if sunscreen is meant to protect us, with its astounding popularity, one would think the skin cancer rates would at least stabilize, if not decrease. Of course, this goes against everything the mainstream media and medical field would have us believe, so let us look at some more facts.
Our Lifestyles Play A Big Part
Around the same time, starting in the 1950’s and beginning to boom around the 1970’s we began to see the wide emergence and acceptance of processed food of all kinds and forms. Microwaves, convenience stores, frozen dinners and fast food started to become the norm. Hydrogenated fat, low fat, zero fat, high protein and diets high in animal products began new trends of eating. By the 1980’s we were well into leading lives based on nutrient-deficient, high calorie, and unnatural food products.
We saw the decrease of wholesome, natural and nutrient-rich foods like fresh fruits and vegetables, raw nuts, seeds, sprouts, beans and real whole grains, as well as home prepared meals. Lifestyle habits were changing, and fast, but unfortunately not for the better. By the 1990’s, aside from the processed foods, diets high in animal products—especially dairy, refined carbs, sugars, salt and unhealthy fats, we saw the emergence of genetically modified foods.
So how does this relate to the increase in skin cancer or any cancer for that matter?
It is now a well-known fact that whole, natural plant foods contain compounds called phytochemicals. While we are still in the early stages of understanding these powerful plant compounds, what we do know thus far is that they are highly beneficial for our health when it comes to healing and prevention. Animal foods do not have phytochemicals. Processed foods do not either, for the most part. Whatever nutrients they may have had are usually stripped out or destroyed during the processing of the food items, necessitating many to be fortified with synthetic nutrients to even have any value for us. We cannot build health or a healthy body if we don’t have the right tools – and the right tools are real, natural nutrients, like vitamins, minerals, antioxidants, and phytochemicals.
What else we know at this point for sure, is that diets high in fruits and vegetables are associated with a reduced risk of cancer. Even the American Cancer Society is kind enough to admit that. In fact, antioxidants—a group of phytochemicals—work to combat free radicals and repair our DNA. Free radicals are damaging molecules that can come to us from numerous sources in our environment, with UV radiation being one of them. Free radicals readily damage our DNA and this is considered one of the main precursors for cancer initiation. Phytochemicals only exist in plant foods and the primary source of antioxidants are also plant foods.
What is amazing about antioxidants as well, is that they provide a two-sided benefit for us. First, they offer preventative benefits, offering us some natural protection against burning and skin damage.Secondly, they provide healing benefits, to repair any damaged areas. Carotenoids like beta-carotene, the precursor for vitamin A, especially when combined with the antioxidant vitamin E, have been shown to decrease and protect against sunburn in individuals.
So over the past few decades, as skin cancer rates continued to rise, our diets continued to decline in quality. It has only been in the last decade that the movement for natural health and optimal nutrition is starting to register with more people. Today, many health experts are beginning to connect the dots that toxic lifestyles and poor nutrition, not sun exposure, are a major cause of sunburns and skin damage.
Chemicals in Sunscreen Cannot Be Ignored
While many of us are still under the impression that commercial personal care products are “safe” for us, the truth about their harmful properties or toxic effects is coming out on a regular basis today. And sunscreens are not exempt from this exposé.
When the sun hits our skin, two main things happen. Depending on the season and time of day, in the presence of UVB rays, it begins the reaction which produces vitamin D in our bodies for us. Hence we can understand why around 3/4 of the population is deficient in vitamin D when we are constantly blocking this reaction, the select times that it is even possible. The second thing is that the sun’s rays signal melanin production in our skin—the pigment made naturally in our bodies—to protect against UV damage.
What is most amazing about melanin and something most people don’t know, is that its photochemical properties make it an excellent photoprotectant. This means it absorbs harmful UV-radiation and transforms the energy into harmless heat through a chemical reaction known as “ultrafast internal conversion”. This property enables melanin to disperse more than 99.9% of the absorbed UV radiation as heat, protecting us from UV damage.
And this brings us to our first problem with sunscreen. The active sunscreen ingredients cannot disperse the energy of the excited state as efficiently as melanin. In fact, these chemicals are potent enough to absorb and render UV rays harmless, which raises concern that they may also cause DNA damage in the skin, the very thing that sun-care products are designed to protect against. This causes a whole slew of problems as penetration of sunscreen ingredients into the lower layers of the skin takes place, increasingthe number of free radicals and harmful reactive oxygen species. On top of that just the heat reaction of many of the chemicals with the sun alone, using our skin as their Petrie dish, has its own questionable concerns.
To add to this, the second main problem is that the very same active ingredients that are needed for a product to have sunscreen properties are harmful to us, even without the presence of the sun or heat. Common names like oxybenzone, PABA, benzophenone, and even avobenzone should be avoided at all costs! See the following article from PressCore.ca for a more thorough list of harmful sunscreen ingredients.
Natural sunscreens contain natural ingredients as the base, and natural minerals like zinc oxide or titanium dioxide as the active ingredients to block the sun. Even though these may not be perfect, they are by far the best natural options available if sunscreen use is necessary.
And if you think this is some fresh or radical news, think again. Apparently studies exist to prove that there are major problems with sunscreen and its link to skin cancer. Naturally the powers that be are slow to face this information as it threatens to bring down a major industry which is making billions of dollars off of us.
Senator Chuck Schumer of New Yorkhas been a leading voice on this issue and you can read more of his findings when it comes to the sunscreen and skin cancer link here.
If the product is doing more harm than good, people have a right to know – and the FDA must take action.
Sen. Chuck Schumer
Natural health expert Mike Adams, the Health Ranger has written a lot on this topic as welland created this video where he shares that sunlight alone does not cause skin cancer.
Similarly, aside from many natural health providers, even some allopathic doctors have spoken up about this issue publicly. The late Dr. A. Bernard Ackerman, who was a dermatologist and director of the Ackerman Academy of Dermatopathology in New York, raised many concerns where the links between the sun, skin cancer and sunscreen are concerned. He has openly stated that there is no evidence to support that sunscreens protect against melanoma.
Another widely known dermatologist and author of the books The UV Advantage and The Vitamin D Solution, Dr. Michael Holick shares similar sentiments in that we should not avoid the sun for optimal health. He teaches about sensible sun exposure and its necessity for proper vitamin D production.
The population of the world has been brainwashed by the American Academy of Dermatology and the sunscreen industry, for 30 years, with the unrelenting message that you should never be exposed to direct sunlight because it is going to cause serious skin cancer and death.
Michael Holick, MD
What About Earth and Sun Changes?
Our discussion would be incomplete without mentioning that yes, the sun, Earth and our atmosphere have also been changing over the past several decades.
Some claims have surfaced that the sun has gotten stronger over the past few decades, and many people go around believing that without there being any solid proof for such claims. While the sun has its natural 11-year cycle or increased and decreased activity, the consensus seems to be that the sun has not gotten stronger or hotter over the past few decades. On the contrary, it has shown a slight cooling trend since 1978 and even the EPA has stated that based on a 25-year record, the effect of changes in the sun’s intensity is estimated to be relatively small in the Earth’s atmosphere.
Where a more plausible explanation exists for the perceived increase in sun intensity, is the loss of parts of the ozone layer. The ozone layer—which protects us from much of the UV radiation—has gone through some turbulent times, thinning out in some areas over the past few decades. This allows more UV radiation to pass through. As we have learned that many of our industrial chemicals were to blame, we have begun to slowly turn things around hoping that the ozone layer will perhaps recover over the next century.However, even on this issue, not all scientists are in agreement and instead point to the political and corporate ties that influence policy, which affects our health, medical and environmental sectors.
What we do know for sure is that the levels and types of UV rays emitted vary drastically based on season, time of day and geographic location. Due to this, there is no one ‘clear cut’ or ‘black and white’ answer when it comes to safe or unsafe sun exposure or sunscreen use.
Based on everything we know, and don’t know, as the pieces of the puzzle continue to come together and build a big picture perspective for us, one thing seems clear: we should NOT BUY or USE ANY of the COMMERCIAL, CHEMICAL sunscreen products—options like Coppertone, Hawaiian Tropic or Banana Boat, just to name a few. There is too much for each of us to risk and lose, by being a pawn in the game of profit and propaganda.
It does not take a scientific study to provide the answers, where common sense can prevail. The sun has been the source of health for humans and other animals, as well as all living beings since the beginning of time. It is an essential part of our life that must simply be respected, not feared or abused. And when it comes to sunscreens, with a little common sense we can also deduce that putting synthetic chemicals on our skin—a living, breathing, permeable organ, and then going out to bake in the sun just doesn’t seem like a smart choice.
When you feel a sunscreen may be necessary, stick to one of the many natural, mineral-based, non-nano particle options available today. To help you find one, consult the EWG’s annual sunscreen guide.
The best way to protect from sun damage and heal any existing damage is as always, by working from the inside out. Change your diet and focus on eating whole, natural, fresh, mostly plant food, while keeping toxins and chemicals found in today’s processed food or drinks out. We know for sure today that you can boost your internal sunscreen by eating antioxidant-rich foods, so why not use Mother Nature’s first and most natural defense mechanism and intelligence. The second best option is to use sun smart habits and cover up with light, loose clothing when needed.
As the years go on and our consciousness,thinking, and habits continue to change, it is my hope that we will be able to see more clearly when it comes to connecting the dots outlined above. For me, that gut feeling I had early on in my life when working at the pharmacy proved true. And so I invite you as well to connect with your inner guidance, honor and respect it, and do what feels most right to you. For me, this means never again using a commercial sunscreen or fearing the sun. Today, I choose to interact with the sun through respect,harmony, and balance, while enjoying its many amazing health benefits.
Active ingredient toxicity
This table outlines human exposure and toxicity information for nine FDA-approved sunscreen chemicals. We asked these questions:
- Will the chemical penetrate skin and reach living tissues?
- Will it disrupt the hormone system?
- Can it affect the reproductive and thyroid systems and, in the case of fetal or childhood exposure, permanently alter reproductive development or behavior?
- Can it cause a skin allergy?
- What if it is inhaled?
- Other toxicity concerns?
|Chemical||EWG Hazard Score||Use in U.S. sunscreens||Skin Penetration||Hormone disruption||Skin Allergy||Other concerns||References|
|UV filters with higher toxicity concerns|
|Oxybenzone||8||Widespread||Detected in nearly every American; found in mother’s milk; 1% to 9% skin penetration in lab studies||Acts like estrogen in the body; alters sperm production in animals; associated with endometriosis in women||Relatively high rates of skin allergy||N/A||Janjua 2004, Janjua 2008, Sarveiya 2004, Gonzalez 2006, Rodriguez 2006, Krause 2012|
|Octinoxate (Octylmethoxycinnamate)||6||Widespread||Found in mothers’ milk; less than 1% skin penetration in human and laboratory studies||Hormone-like activity; reproductive system, thyroid and behavioral alterations in animal studies||Moderate rates of skin allergy||N/A||Krause 2012, Sarveiya 2004, Rodriguez, 2006, Klinubol 2008|
|UV filters with moderate toxicity concerns|
|Homosalate||4||Widespread||Found in mothers’ milk; skin penetration less than 1% in human and laboratory studies||Disrupts estrogen, androgen and progesterone||N/A||Toxic breakdown products||Krause 2012, Sarveiya 2004, SCCNFP 2006|
|Octisalate||3||Widespread; stabilizes avobenzone||Skin penetration in lab studies||N/A||Rarely reported skin allergy||N/A||Walters 1997, Shaw 2006 Singh 2007|
|Octocrylene||3||Widespread||Found in mothers’ milk; skin penetration in lab studies||N/A||Relatively high rates of skin allergy||N/A||Krause 2012, Bryden 2006, Hayden 2005|
|UV filters with lower toxicity concerns|
|Titanium Dioxide||2 (topical use), 6 (powder or spray)||Widespread||No finding of skin penetration||No evidence of hormone disruption||None||Inhalation concerns||Gamer 2006, Nohynek 2007, Wu 2009, Sadrieh 2010, Takeda 2009, Shimizu 2009, Park 2009, IARC 2006b|
|Zinc Oxide||2 (topical use), 4 (powder or spray)||Widespread; excellent UVA protection||Less than 0.01% skin penetration in human volunteers||No evidence of hormone disruption||None||Inhalation concerns||Gulson 2012, Sayes 2007, Nohynek 2007, SCCS 2012|
|Avobenzone||2||Widespread; best UVA protection of chemical filters||Very limited skin penetration||No evidence of hormone disruption||Breakdown product causes relatively high rates of skin allergy||Unstable in sunshine, must be mixed with stabilizers||Klinubol 2008, Bryden 2006, Hayden 2005, Montenegro 2008, Nash 2014|
|Mexoryl SX||2||Uncommon; pending FDA approval; offers good, stable UVA protection||Less than 0.16% skin penetration in human volunteers||No evidence of hormone disruption||Skin allergy is rare||N/A||Benech-Kieffer 2003, Fourtanier2008|
|Six other ingredients approved in the U.S. are rarely used in sunscreens: benzophenone-4, benzophenone-8, menthyl anthranilate, PABA, Padimate O, and trolamine salicylate|
Several common chemical filters appear to be endocrine disruptors. A large number of studies in animals and cells have shown that the chemicals affect reproduction and development by altering reproductive and thyroid hormones, although the evidence is mixed for some studies (Krause 2012). Animal studies report lower sperm counts and sperm abnormalities after exposure to oxybenzone and octinoxate, delayed puberty after exposure to octinoxate and altered estrous cycling for female mice exposed to oxybenzone. Recently, Danish researchers reported that eight of 13 chemical sunscreen ingredients allowed in the U.S. affected calcium signaling of male sperm cells in laboratory tests, which the researchers suggest could reduce male fertility (Endocrine Society 2016).
As most of the hazard data is generated from animal studies, it is difficult to determine the human health implications of exposure to a mixture of hormone-disrupting ingredients in sunscreen.
In addition to the relationship between oxybenzone and testosterone levels in adolescents, preliminary investigations by a team of researchers at the NIH and SUNY Albany suggest a link between higher concentrations of benzophenones and poorer reproductive success in men seeking assistance at a fertility clinic. Men with greater exposures to benzophenone-2 and/or 4-hydroxyoxybenzone had poorer sperm quality (Louis 2015), and reported that it took longer for their partner to conceive (Buck-Louis 2014). Female exposures to oxybenzone and related chemicals have been linked to increased risk of endometriosis (Kunisue 2012)
Mineral sunscreens are made with zinc oxide and titanium dioxide, usually in the form of nanoparticles.
Mineral sunscreens are made with zinc oxide and titanium dioxide, usually in the form of nanoparticles. There is good evidence that little if any zinc or titanium particles penetrate the skin to reach living tissues. Thus, mineral sunscreens tend to rate better than chemical sunscreens in the EWG sunscreen database. However, it is important that manufacturers use forms of minerals that are coated with inert chemicals to reduce photoactivity. If they don’t, users could suffer skin damage. To date, no such problems have been reported.
The FDA should set guidelines and place restrictions on zinc and titanium in sunscreens to minimize the risks to sunscreen users and maximize these products’ sun protection. Our detailed analysis of nanoparticles in sunscreens is available here.
The FDA must also take a close look at the so-called inactive ingredients in sunscreens. These typically make up 50 to 70 percent of a sunscreen product
One ingredient in particular is a cause for concern: methylisothiazolinone, a preservative. This year, EWG has found methylisothiazolinone is listed on the labels of 94 sunscreens including six marketed to children. Methylisothiazolinone is used alone or in mixtures with a related chemical preservative called methylchloroisothiazolinone
The American Contact Dermatitis Society named methylisothiazolinone its “allergen of the year” in 2013.
Laboratory studies indicate that methylisothiazolinone is a skin sensitizer or allergen. Over the past several years, physicians have reported serious cases of serious skin allergies, most notably in children exposed to methylisothiazolinone, from baby wipes and other products meant to be left on the skin (Chang 2014). In a study published in 2014, researchers at Baylor University surveyed the ingredients in 152 children’s body care products labeled “hypoallergenic” and found methylisothiazolinone in 30 of them (Schlichte 2014).
In 2015, researchers from 15 clinics in the U.S. and Canada reported an increase in MI allergy in patients. The researchers concluded that they had documented “the beginning of the epidemic of sensitivity to methylisothiazolinone in North America” (Warshaw 2015).
That MI has become relatively common in sunscreen is a matter of concern because sunscreen users are likely to be exposed to significant concentrations of this chemical. The products that contain MI are intended to be applied to large portions of the body and to be reapplied often.
In March 2015, the European Scientific Committee on Consumer Safety concluded that no concentration of MI could be considered safe in leave-on cosmetic products (EU SCCS 2014).
MI is allowed in U.S. products. Last September, the Cosmetics Ingredient Review expert panel – an independent, cosmetics-industry-funded body the American cosmetics industry pays to advise it on the safety of cosmetics ingredients – told the industry that MI was safe for use in body care products as long as manufacturers come up with formulations that wouldn’t cause allergic reactions (CIR 2014). Since FDA has the little legal power to regulate cosmetics ingredient safety, it has authorized the cosmetics industry to police itself through this CIR panel. The body’s recommendations are not legally binding on any company. In several decades, it has declared only 11 ingredients or chemical groups to be unsafe (CIR 2012).
EWG recommends that the FDA launch a more thorough investigation of the safety of all ingredients currently in sunscreens to ensure that none of them damaged skin or cause other toxic effects in consumers.
Nanoparticles in Sunscreens
Sunscreens made with zinc oxide and titanium dioxide generally score well in EWG’s ratings because:
- They provide strong sun protection with few health concerns.
- They don’t break down in the sun.
- Zinc oxide offers good protection from UVA rays. Titanium oxide’s protection isn’t as strong, but it’s better than most other active ingredients.
Nanoparticles in American sunscreens are either titanium dioxide or zinc oxide.
Zinc oxide is EWG’s first choice for sun protection. It is stable in sunlight and can provide greater protection from UVA rays than titanium oxide or any other sunscreen chemical approved in the U.S.. Years ago, zinc oxide sunscreens, often seen on lifeguards’ noses, were famously white and chalky. Today, sunscreen makers use zinc oxide nanoparticles to formulate lotions with less white tint.
A number of companies sell products advertised as containing “non-nano” titanium dioxide and zinc oxide. These claims are generally misleading. While particle sizes vary among manufacturers, nearly all would be considered nanomaterials under a broad definition of the term, including the definition proposed in 2011 by the federal Food and Drug Administration (FDA 2011b). For example, Antaria, a popular supplier of zinc oxide, initially claimed it was selling a “non-nano” form to sunscreen makers. But under pressure from Friends of the Earth Australia, it acknowledged that its zinc oxide would be considered a nanomaterial requiring special labeling in Europe (Antaria 2012, Friends of the Earth 2012). There is even less dispute about titanium dioxide. According to the available information, it must be delivered in nanoparticle form to render a sunscreen reasonably transparent on the skin.
The use of nanoparticles in cosmetics poses a regulatory challenge because the properties of nanoparticles may vary tremendously, depending on their size, shape, surface area and coatings. We don’t know everything we would like to know about their performance because manufacturers are not required to disclose the qualities of the particles used in their sunscreens.
More research and more specific FDA guidelines are essential to reduce the risk and maximize the sun protection of mineral sunscreens. Yet, even with the existing uncertainties, we believe that zinc oxide and titanium dioxide lotions are among the best choices on the American market.
- The shape and size of the particles affect sun protection. The smaller they are, the better the SPF protection and the worse the UVA protection. Manufacturers must strike a balance: small particles provide greater transparency but larger particles offer greater UVA protection. The form of zinc oxide most often used in sunscreens is larger and provides greater UVA protection than the titanium dioxide products that appear clear on the skin.
- Nanoparticles in sunscreen don’t penetrate the skin. Some studies indicate that nanoparticles can harm living cells and organs when administered in large doses. But a large number of studies have produced no evidence that zinc oxide nanoparticles can cross the skin in significant amounts (SCCS 2012). A real-world study tested penetration of zinc oxide particles of 19 and 110 nanometers on human volunteers who applied sunscreens twice daily for five days (Gulson 2010). Researchers found that less than 0.01 percent of either form of zinc entered the bloodstream. The study could not determine if the zinc in the bloodstream was insoluble nanoparticles, therefore the European regulators concluded it was most likely zinc ions, which would not pose any health risk (SCCS 2012). Other FDA- and European Union-sponsored studies concluded that nanoparticles did not penetrate the skin (NanoDerm 2007, Sadrieh 2010).
- It is unlikely that nanoparticles in sunscreen cause skin damage when energized by sunlight. Titanium dioxide, and to a lesser extent zinc oxide, are photocatalysts, meaning that when they are exposed to UV radiation they can form free radicals that damage surrounding cells. Nanoparticle sizes of these minerals are more affected by UV rays than larger particles.
Sunscreen manufacturers commonly employ surface coatings that can dramatically reduce the potential for photoactivity, with data suggesting that they reduce UV reactivity by as much as 99 percent (SCCNFP 2000, Pan 2009). In sunscreens, problems may arise if particles are not treated with inert coatings, if the coatings are not stable, or if manufacturers use forms of zinc oxide or titanium dioxide that are not optimized for stability and sun protection. However, tests of living skin from human volunteers and animal testing suggest that these hazards are not a concern for human safety because the free radicals that are generated by nanoparticles on skin are quenched by the skin’s own antioxidant protections (Popov 2009, Osmond 2010).
Information from suppliers suggests that U.S. sunscreen formulators generally employ the appropriate forms of zinc oxide and titanium dioxide in their products. Recent studies from other countries indicate that manufacturers do not always use sunscreen-grade minerals (Barker 2008, Friends of the Earth 2012). Since manufacturers are not required to make this information public, the extent of these problems is difficult to gauge. The European Union reviewed 15 types of coated titanium dioxide in sunscreen and concluded manufacturers could use any of these forms in their products (SCCS 2013b). They specified that other types will also be allowed as long as manufacturers can provide data demonstrating their safety. For zinc oxide sunscreens, both coated and uncoated particles are allowed (SCCS 2014).
- Nanoparticles could cause lung damage when inhaled. Inhalation of nanoparticles is dangerous for many reasons. EWG strongly discourages the use of loose powder makeup or spray sunscreens using titanium dioxide or zinc oxide of any particle size.
The International Agency for Research on Carcinogens has classified titanium dioxide as a possible carcinogen when inhaled in large doses (IARC 2006b). The lungs have difficulty clearing small particles, and the particles may pass from the lungs into the bloodstream. Insoluble nanoparticles that penetrate skin or lung tissue can cause extensive organ damage.
Nanoparticles in lip sunscreens can be swallowed and might damage the gastrointestinal tract, although there are no studies to suggest that consumers swallow enough zinc oxide or titanium dioxide to pose a concern. The risks are less if digestion alters the properties of the particles reaching the intestines. There are lots of uncertainties about the degree of risk. We know that titanium dioxide has been used for decades as a colorant in commonly eaten foods, including doughnuts and M&Ms, and a recent study found that these particles would be classified as nanoparticles (Weir 2012).
- Do current federal sunscreen regulations ensure the safety and effectiveness of sunscreen minerals? No. The U.S. government has not enacted regulations, guidelines or recommendations on particle characteristics that would maximize sun protection and minimize health risks. As a consumer you are not likely to find detailed information about the nanoparticles on product labels or from companies who make these products.
Nanoscale zinc was only recently approved for use in European sunscreens, except in sprays and powders (EU SCCS 2012). FDA sunscreen rules allow any type of titanium dioxide or zinc oxide to be used in sunscreens (FDA 2011a). In order to ensure the safety and effectiveness of nanominerals in sunscreen, the FDA should restrict forms of zinc and titanium that would provide inadequate UV protection, or that could be activated by UV rays and damage skin cells.
EWG maintains ongoing vigilance in its assessment of sunscreen safety. At present, all available evidence suggests that zinc oxide and titanium dioxide can be safely used in sunscreen lotions applied to healthy skin. The weight of evidence indicates that both zinc oxide and titanium dioxide pose a lower hazard than most other sunscreen ingredients approved for the U.S. market.
EWG’s favorable rating of nanoparticle sunscreens is not an endorsement of nanomaterials in commerce. EWG has urged the FDA to review carefully the safety of nanosize particles used in cosmetics products, and to evaluate skin and lung penetration and the potential for greater toxicity to body organs (EWG 2007, 2011). In the case of sunscreens, the potential for human exposure at the consumer level has been carefully studied. Unlike other consumer products with nanomaterials, sunscreens play an important role in cancer prevention.
EWG remains deeply concerned about the general lack of oversight of nanotechnology and associated risks to consumers, people with workplace exposures and the environment. Government regulators should exercise strong oversight to ensure that the production, use and disposal of nanomaterials do not harm workers and the environment. More than 50,000 tons of nanoparticle titanium dioxide were produced in 2010 (Future Markets 2011), yet few rules govern the use of protective equipment and other controls to limit inhalation or ingestion during product formulation. A more thorough and complete assessment of worker risk and environmental outcomes is urgently needed.
When zinc oxide and titanium dioxide nanoparticles wash off skin, they enter the environment, with unknown effects. The implications of nanoparticle pollution for the environment have not been sufficiently assessed (Börm 2006).
The potential negative environmental effects of nanoscale and conventional zinc and titanium should be carefully studied and weighed against the environmental impact of other UV blockers. Sunscreen ingredients have been shown to damage coral, accumulate in fish and the environment, and disrupt hormones in fish and amphibians (Buser 2006, Danovaro 2008, Giokas 2007, Kunz 2004, Kunz 2006, Weisbrod 2007).
For all sunscreens, including nanoscale zinc and titanium, there is an urgent need to carry out thorough environmental assessments so that regulators have the data they need to begin to control hazards associated with widespread use of these and other chemical ingredients in personal care products.
EWG’s 2017 Sunscreen Guide was researched and written by David Andrews, Ph.D., senior scientist; Sean Gray, M.S., director of consumer database architecture; Nneka Leiba, M.P.H., deputy director of research; Sonya Lunder, M.P.H., senior analyst; Paul Pestano, M.S., senior database analyst; and interns Shey Browne and Elizabeth Lee.
EWG’s 11th annual analysis of sunscreens comprises hazard and efficacy ratings for more than 880 sunscreens, more than 480 SPF-labeled moisturizers and 120 lip products. The ratings are based on an in-house compilation of standard industry, government and academic data sources; models we constructed over the past 11 years; and a thorough review of the technical literature on sunscreens.
The sunscreen ratings from this investigation have been incorporated into EWG’s Skin Deep® cosmetics database, an online consumer tool available at www.ewg.org/skindeep.
We based the analysis on sunscreen ingredient listings obtained primarily from online retailers and the Food and Drug Administration’s online database of Over the Counter Drug Labels (FDA 2016).
Products are rated on five factors encompassing overall ingredient hazard and product efficacy in providing sun protection:
- Health hazards associated with listed ingredients (based on a review of nearly 60 standard industry, academic, government regulatory and toxicity databases).
- UVB protection (using SPF rating as the indicator of effectiveness).
- UVA protection (using a standard industry absorbance model).
- Balance of UVA/UVB protection (using the ratio of UVA absorbance to SPF).
- Sunscreen stability (how quickly an ingredient breaks down in the sun, using an in-house stability database compiled from published findings of industry and peer-reviewed stability studies).
The overall rating for each product was calculated on the basis of a formula reflecting a combination of the product’s health hazard and efficacy ratings. Efficacy accounts for two-thirds of the score for products with lower health hazard concerns and for one-half the score in products with high health hazard scores.
The methods and content of the analysis were based on EWG’s review of the technical literature, including hundreds of industry and peer-reviewed studies.
Results of the analysis appear in EWG’s online, interactive sunscreen guide. Details of the methodology are described below.
Health hazard scores were based on the ingredient health hazard scoring system of EWG’s Skin Deep database (www.ewg.org/skindeep). This core database of chemical hazards, regulatory status and study availability pools data from nearly 60 databases and from government agencies, industry panels, academic institutions or other credible bodies.
The information in Skin Deep is used to create hazard ratings and data gap ratings for both personal care products and individual ingredients.
Additionally, the hazard scores for mineral ingredients were adjusted to account for exposure potential calculated from evidence regarding skin penetration or absorption, as described in greater detail on the Skin Deep “About” page.
We gave additional weight in the calculated hazard scores to properties of particular concern for sunscreens, including products that contain oxybenzone or vitamin A, products in a spray or powder form that may pose a risk when inhaled, and products listing SPF values exceeding “SPF 50+, the limit suggested by the FDA in its 2011 proposed regulation (FDA 2011a, 2011b).
For sunscreens with a single significant concern, we assigned a rating no lower than 3 (moderate hazard), and for sunscreens with two or more significant concerns, we assigned a rating no lower than 7 to reflect a higher level of concern.
Health hazard scores in the sunscreen evaluations reflect hazards specific to sunscreens, as well as beneficial or potentially harmful effects of specific active ingredient combinations.
We assessed hazards identified by government, industry and academic sources, but did not evaluate specific claims made by individual manufacturers.
This report includes a closer look at the 17 chemicals permitted by the FDA for use as active ingredients in sunscreens – including the various particle sizes of the inorganic sunscreen ingredients zinc oxide and titanium dioxide – as well as the 52 chemicals used in other countries to prevent UV exposure that are added to U.S. sunscreens for other purposes.
We compiled relevant information from sources that included published reports in the peer-reviewed literature and risk assessments from the European Union, Japan and Australia, and other countries with robust sunscreen regulations.
Assessing Known or Suspected Chemical Hazards
Sunscreens sold in the U.S. are considered over-the-counter drugs. They contain active ingredients that must undergo safety and effectiveness testing, and inactive ingredients that – as with virtually all other personal care products – are not required to be tested for safety. We used different approaches to
We used different approaches to evaluating active and inactive ingredients.
Active ingredients, as well as specific active ingredient combinations, were evaluated based on an extensive review of the scientific literature. The review included peer-reviewed literature, filed and approved patents and reviews by the government and industry panels, as well as cross-checks with EWG’s Skin Deep database.
Inactive ingredient assessments were conducted using the existing Skin Deep system cited above (EWG 2017). Skin Deep identifies chemicals that pose health hazards, including known and probable carcinogens; reproductive and developmental toxicants; neurotoxic chemicals; skin irritants and allergens; chemicals flagged for persistence, bioaccumulation, and toxicity in the environment; as well as chemicals banned or restricted in other countries. Skin Deep assessments also highlight the extensive data gaps for the majority of ingredients used in cosmetics and personal care products.
Skin Deep assessments also highlight the extensive data gaps for the majority of ingredients used in cosmetics and personal care products.
Briefly, EWG’s hazard ratings are a synthesis of known and suspected hazards associated with ingredients and products. Skin Deep’s hazard ratings are categorized as raising low, moderate or higher concern, with numeric rankings that range from 0 (low concern) to 10 (higher concern). Data gap ratings describe the extent to which ingredients or products have been definitively assessed for hazards. Data gap ratings are represented in Skin Deep by a numeric percentage ranging from 100 percent (complete absence of hazard data) to 0 percent (comprehensive hazard data).
Data gap ratings describe the extent to which ingredients or products have been definitively assessed for hazards. Data gap ratings are represented in Skin Deep by a numeric percentage ranging from 100 percent (complete absence of hazard data) to 0 percent (comprehensive hazard data).
Data gap ratings describe the extent to which ingredients or products have been definitively assessed for hazards. Data gap ratings are represented in Skin Deep by a numeric percentage ranging from 100 percent (complete absence of hazard data) to 0 percent (comprehensive hazard data).
Sunscreen Efficacy (Sun Hazard)
Overview of Sunscreen Efficacy Evaluation
In the analysis of product effectiveness, we weighed four contributing factors:
- UVB protection
- UVA protection
- UVA/UVB balance
- Stability of active ingredient combinations, considering both the potential for active ingredient molecules to break down in sunlight, react with other ingredients or otherwise transform into compounds less effective at filtering UV radiation.
We assigned a score for each factor based on an evaluation of the labeled SPF, EWG-modeled UV protection and the technical literature on sunscreen stability.
We derived an overall rating for product effectiveness (sun hazard) as the sum of these four factors, weighted by their relative importance. In this calculation, we assigned a weight of 0.28 each to UVA protection, UVB protection, and UVA/UVB balanced protection and a weight of 0.16 to stability. The procedures are described in greater detail below.
1. Evaluating Effectiveness of UVB Protection
UVB protection is based on each product’s SPF, or sun protection factor, rating as labeled on the product.
We scored UVB protection from sunscreens with SPF values between 15 and 110 as effective for sunburn protection, with a score of zero. This is based on the assumption that consumers would pick a product with the appropriate SPF based on their skin tone, solar intensity and time outdoors. Sunscreens with SPF values lower than 15 are not evaluated in our database.
This is based on the assumption that consumers would pick a product with the appropriate SPF based on their skin tone, solar intensity and time outdoors. Sunscreens with SPF values lower than 15 are not evaluated in our database.
When EWG modeled SPF value for a given product that was less than half of the labeled value, we added three points to the product’s overall score because of concerns about the efficacy of the product and the likely use of non-monograph ingredients to boost the SPF value. EWG is concerned that SPF boosters are increasingly common in U.S. sunscreens. Many inhibit sunburn but do not appear to change the absorbance spectrum of sunscreen (Kobo 2015), meaning that
EWG is concerned that SPF boosters are increasingly common in U.S. sunscreens. Many inhibit sunburn but do not appear to change the absorbance spectrum of sunscreen (Kobo 2015), meaning that that they do not prevent UV rays from striking skin. There are serious, unanswered questions about whether these ingredients protect skin from other types of UV damage.
There are serious, unanswered questions about whether these ingredients protect skin from other types of UV damage.
Modeling Sunscreen Efficacy to Evaluate Products’ UVA Protection
To score products on UVA protection (Section 2) and the balance of UVA to UVB protection (Section 3), we modeled the effectiveness of the sunscreen based on the active ingredients. Modeling the efficacy of sunscreen products based on the active ingredients is standard industry practice (BASF 2013). Modeling requires the absorbance spectrum for the active ingredient and the percent of the active ingredient used in the product.
Modeling the efficacy of sunscreen products based on the active ingredients is standard industry practice (BASF 2013). Modeling requires the absorbance spectrum for the active ingredient and the percent of the active ingredient used in the product.
Absorbance Spectra for Active Ingredients
Absorbance spectra are determined through experiments in which researchers measure the amount and type of UV light filtered out by an ingredient or ingredient combination at every wavelength along the UVA and UVB spectrum. With absorbance spectra, researchers determine the theoretical effectiveness of sunscreen ingredients and sunscreen products in preventing UV radiation from reaching the skin.
With absorbance spectra, researchers determine the theoretical effectiveness of sunscreen ingredients and sunscreen products in preventing UV radiation from reaching the skin.
Figure 1: Example of modeled absorption spectrum of avobenzone
|4-Methylbenzylidine Camphor (4-MBC)||(Vanquerp 1999)|
|Avobenzone (Parsol 1789 | Butyl Methoxydibenzoylmethane)||(Bonda 2005, BASF 2010)|
|Ensulizole (Phenylbenzimidazole Sulfonic Acid)||(Inbaraj 2002)|
|Homosalate||(Sánchez and Cuesta 2005)|
|Menthyl Anthranilate (Beeby and Jones 2000)||(Beeby 2000)|
|Mexoryl SX||(Herzog 2005b)|
|Sunscreen Grade Titanium Dioxide||(Schlossman 2005)1|
|Sunscreen Grade Zinc Oxide||(Schlossman 2005, EWG 2010, BASF 2009, Nanox 2009)1|
|Octinoxate (Octyl Methoxycinnamate)||(Bonda 2005)|
|Octisalate (Octyl Salicylate)||(Krishnan 2004)|
|Oxybenzone (Benzophenone-3)||(Vanquerp 1999)|
|Padimate O (Octyl Dimethyl PABA | PABA Ester)||(Krishnan 2004)|
|Sulisobenzone (Benzophenone-4) (CIR 2006)||(Sánchez 2005)|
|Tinosorb M (MBBT)||(Herzog 2005b)|
|Tinosorb S||(Herzog 2005b)|
1 For inorganic active ingredients – titanium dioxide and zinc oxide – the “absorbance spectra” also takes into account the chemical’s ability to scatter UV radiation in the UVA range (Schlossman and Shao 2005). Two different zinc oxide spectra are used to reflect the large variation in efficacy with changing particle size. The default categorization for zinc oxide ingredients is particle size >100 nm (Lewicka 2011).
Absorbance spectra are represented in most of these sources either in the graphic or tabular format as a function of wavelength. To use these absorbance spectra in our computations of sunscreen effectiveness, we developed an equation to represent each measured spectrum. When necessary, we digitized the graphical absorbance spectra from the sources listed above. We used the graphing and statistical analysis software package xmGrace (Turner 2004) to determine the best-fit polynomial expression for each absorbance spectrum. The maximum error between the digitized data and final fitted values was 1 percent, and for any given point was less than 0.05 percent in most cases.
Monochromatic Protection Factor (MPF) and Transmission Spectra for Ingredients and Products
Both SPF and MPF are unitless factors that provide a measure of the amount of UV radiation blocked by sunscreen. SPF is a single value, while MPF varies based on wavelength. In the U.S., SPF is derived from sunburn experiments on human volunteers, while MPF is derived from lab measurements of UV transmission (Herzog 2005). SPF can also be computed by combining the MPF spectrum with the effective action spectrum for sunburn, a measure of how much damage a particular wavelength of light will cause (McKinlay 1987).
The MPF is a measure of the amount of UV radiation blocked (i.e., absorbed or scattered) at a particular wavelength and is a key component in EWG’s evaluation of sunscreen effectiveness. We developed UV transmission spectra for individual active ingredients and for all combinations of active ingredients in the products assessed. Our report uses the MPF transmission spectrum to graphically represent the effectiveness of sunscreen products and ingredients across the UV spectrum and to calculate the effectiveness of products in the UVA range. In the UVB range, we use SPF instead of MPF as the measure of product effectiveness.
We computed the MPF transmission spectra following the method detailed by Herzog and implemented by the BASF sunscreen simulator, formerly known as the Ciba sunscreen simulator (Herzog 2002, Herzog 2006, BASF 2011). This model accounts for the effect of uneven skin surfaces – skin is not a smooth surface, but a series of ridges and valleys. The model represents sunscreen on the skin as an unevenly distributed thin film. The sunscreen thickness is modeled using a continuous height distribution that matches a gamma distribution function (Ferrero 2003). The gamma method provides a significant improvement in the calculated correlation with measured SPF over the previously used two-step model (O’Neill 1984).
MPF is given by:
where T is the percent transmission of light, ε(λ) is the average molecular absorption coefficient (as defined by Herzog), c is the average molar concentration of the active ingredients in moles/liter, d is the path length (20 micrometers is the assumed thickness of sunscreen based upon the recommended applied dose of 2 mg/cm2), and g and f are parameters fitted by Herzog (Herzog 2002, Herzog 2006) to match experimental data on European sunscreens equaling 0.269 and 0.935, respectively. Once the transmission spectrum is obtained, it can be transformed into an absorbance spectrum and MPF.
We used the Herzog method (Herzog 2002, Herzog 2006) described above to compute the UV transmission spectra both for individual ingredients and for all variations of active ingredients in the products assessed. The method requires inputting the concentrations of active ingredients. In computations of MPF spectra for individual ingredients, we used the average concentration of that ingredient found in the products assessed. In computations of MPF spectra, we used the concentrations of active ingredients specified on the product label. For some products, the concentrations of active ingredients were not available. In those cases, we used the following hierarchy to establish assumed concentrations of active ingredients used in the MPF analysis:
- The average concentration of active ingredient for products with the same SPF and active ingredient combination.
- The average concentration of active ingredient for products with the same SPF and an active ingredient in a different combination.
- The average concentration of active ingredient for products with the same ingredient combination over all available SPFs.
- The average concentration of active ingredient for all products containing that active ingredient.
We evaluated sunscreen effectiveness based in part on our computation of the transmission spectrum for a product’s combination of active ingredients. We integrated over the combined effective absorbance spectrum as described by Herzog (Herzog 2002, Herzog 2006) over 1 nm wavelength intervals to obtain overall sunscreen product spectra based on the individual ingredient spectra described above. The spectral information is presented in this report over 10 nm wavelength intervals.
The spectral information is presented in this report over 10 nm wavelength intervals.
A sunscreen product must generally contain multiple active ingredients to achieve a high SPF rating due to FDA-imposed concentration limits and constraints on product formulation (Chatelain 2001).
2. Calculating the UVA Protection Score
In evaluating overall UVA effectiveness, the percentage of UVA light blocked or absorbed was calculated from our modeled spectrum of the product. This calculation provides a numeric measure of the degree of UVA protection. This value was calculated by integrating the MPF between 320 to 400nm.
Using this method, a score was assigned to each product:
Table 1: UVA score and percent of UVA light blocked
|Percent UVA blocked or absorbed||UVA protection score|
3. Calculating UVA/UVB Protection Balance
Government agencies, sunscreen researchers and the American Association of Dermatology recognize the need for sunscreens to offer proportionate protection from UVA and UVB radiation.
In 2009 we shifted from the spectral uniformity index for measuring sunscreen balance to a method based on the ratio of our modeled UVA-PF to the labeled SPF. This method better accounts for imbalance, particularly in the high-SPF range, and relies directly on manufacturers’ measured SPF values rather than modeled values.
This method better accounts for imbalance, particularly in the high-SPF range, and relies directly on manufacturers’ measured SPF values rather than modeled values.
We calculated a balance factor for each sunscreen as the ratio of the UVA Protection Factor (UVA-PF) for persistent pigment darkening to the SPF value listed on product labels.
Using this method, a UVA/UVB balance score was assigned to each product:
Table 2: UVA/UVB balance score scoring
|Ratio of UVA-PF/SPF||UVA/UVB Balance Score|
Calculating the Number of Sunscreens that Meet the European COLIPA UVA Standard
The European standard for UVA protection in sunscreens set by Cosmetics Europe requires sunscreens to have both a critical wavelength of 370 nm and a ratio of UVA protection factor to SPF greater than one to three. The UVA protection factor is calculated by weighting the absorbance spectrum between 320 to 400 nm with the persistent pigment darkening action spectra (Cosmetics Europe 2011).
The UVA protection factor is calculated by weighting the absorbance spectrum between 320 to 400 nm with the persistent pigment darkening action spectra (Cosmetics Europe 2011).
The FDA Standard for Broad Spectrum Protection
Starting in 2012, sunscreens sold and labeled as providing broad-spectrum protection have been required to have a critical wavelength of 370 nm (FDA 2011). The new FDA standards do little to differentiate mediocre from excellent products. The standards have been criticized for providing no incentive for improvement (Diffey 2012).
The new FDA standards do little to differentiate mediocre from excellent products. The standards have been criticized for providing no incentive for improvement (Diffey 2012).
4. Ingredient Stability
Absorption of UV light causes many sunscreen active ingredients to undergo chemical reactions or structural changes on the skin. In most cases, these ingredients quickly return to their original form to absorb more energy. However, ingredients can also degrade and may lose their UV protectiveness. One study found that seven of 14 common sunscreens in Europe photo-degraded significantly after exposure to UV radiation, specifically UVA radiation (Shaath 1990).
In most cases, these ingredients quickly return to their original form to absorb more energy. However, ingredients can also degrade and may lose their UV protectiveness. One study found that seven of 14 common sunscreens in Europe photo-degraded significantly after exposure to UV radiation, specifically UVA radiation (Shaath 1990).
In certain cases, degradation may produce other chemicals that are toxic to skin and body cells, especially if the sunscreen has been absorbed into the skin (Gasparro 1997), or the reactions can speed up – or catalyze – degradation of other ingredients in the sunscreen mixture (Bonda 2005).
Ideally, EWG would like to have laboratory results of photodegradation for every active ingredient in every sunscreen product. However, since this information is not publicly available and such testing is not required of manufacturers, we analyzed a large number of studies from various sources. In quantifying these studies, it is difficult to compare results because of differences in the experimental conditions, such as solvent versus sunscreen formulation, measurement of light energy and sample preparation. Additionally, the degradation rate of an ingredient in a dilute laboratory solvent such as water or ethanol may or may not be representative of the results during consumer use. Even results in one sunscreen formulation may not be representative of the results in another because of variations in how active ingredients behave in different environments.
However, since this information is not publicly available and such testing is not required of manufacturers, we analyzed a large number of studies from various sources.
In quantifying these studies, it is difficult to compare results because of differences in the experimental conditions, such as solvent versus sunscreen formulation, measurement of light energy and sample preparation. Additionally, the degradation rate of an ingredient in a dilute laboratory solvent such as water or ethanol may or may not be representative of the results during consumer use. Even results in one sunscreen formulation may not be representative of the results in another because of variations in how active ingredients behave in different environments.
Even results in one sunscreen formulation may not be representative of the results in another because of variations in how active ingredients behave in different environments.
EWG performed linear regression analyses of percent degradation versus minimal erythemal dose (MED) exposures in solvent and sunscreen formulations. The regression equations for solvent and sunscreen systems were then weighted equally and classified into three categories:
Table 3: Scoring ingredient stability
|Stability classification||Extent of Photo-degradation after 2 hours of peak intensity sun exposure (10 MEDs)|
|Major photodegradation||Over 25% breakdown|
|Minor photodegradation||5% to 25% breakdown|
|No photodegradation (Photo-stable)||Less than 5% breakdown|
We weighted solvent and formulation results equally because of the wide variation in test conditions and the possibility that a single sunscreen formulation may not be representative of other formulations.
There is insufficient information in the literature on the subject of photostability to reliably guide a sunscreen formulator, let alone the consumer. Our classifications are presented here:
Table 4: Degradation of active ingredients
|Active ingredient||Classification percent||Degradation with exposure to 10 MEDs|
|4-Methylbenzylidine Camphor (4-MBC) (Deflandre 1988; Vanquerp 1999)||None||Less than 1|
|Avobenzone (Parsol 1789 | Butyl Methoxydibenzoylmethane) (Deflandre 1988; Shaath 1990; Roscher 1994; Schwack 1995)||Major||42.1|
|Ensulizole (Phenylbenzimidazole Sulfonic Acid) (Deflandre 1988, Serpone 2002) — Deflandre found insignificant degradation in a sunscreen formulation, Serpone measured fast degradation in various solvents.||Major||46.6|
|Homosalate (Berset 1996, Herzog 2002)||Minor||6.7 – 60|
|Menthyl Anthranilate (Beeby 2000)||None||No degradation|
|Mexoryl SX (TDSA) (Deflandre 1988, Cantrell 1999, Herzog 2005)||Minor||21.2|
|Micronized Titanium Dioxide (Schlossman and Shao 2005)||None||No degradation|
|Micronized Zinc Oxide (Schlossman and Shao 2005)||None||No degradation|
|Octinoxate (Octyl Methoxycinnamate) (Deflandre 1988, Shaath 1990, Berset 1996, Chatelain 2001, Serpone 2002)||Minor||24.8|
|Octisalate (Octyl Salicylate) (Shaath 1990, Bonda 2005)||None||3.3|
|Octocrylene (Shaath 1990, Bonda 2005)||None||1.6|
|Oxybenzone (Benzophenone-3) (Deflandre 1988, Shaath 1990, Roscher 1994, Berset 1996, Chatelain 2001, Serpone 2002)||Minor||21.9|
|Padimate O (Octyl Dimethyl PABA | PABA Ester) (Deflandre 1988, Serpone 2002)||Major||44.7|
|Sulisobenzone (Benzophenone-4) (CIR 2006)||None||No degradation expected|
|Tinosorb M (MBBT) (Herzo, 2002, Herzog 2005)||None||1|
|Tinosorb S (BEMT) (Chatelain 2001, Bonda 2005, Damiani 2007)||None||1|
In order to account for a situation where an individual ingredient may photo-degrade but the sunscreen itself continues to provide significant protection due to the presence of other active ingredients, we assumed that the UV-blocking effectiveness of an active ingredient experiencing major degradation is reduced by 50 percent, and the UV-blocking effectiveness of an active ingredient with minor degradation is reduced by 25 percent.
We then reintegrated over the entire spectrum and compared the degraded spectrum to the original. UVA and UVB protection were weighted equally. Based on the relative amount of degradation, the following scores were applied separately to the UVA and UVB portions:
Table 5: Stability scoring
|% blocking remaining after 10 MED (approximately 2 hours of sun exposure)||Score|
|% Area >90%||0|
|80 < % Area< 90%||1|
|70% < % Area< 80%||2|
|60% < % Area< 70%||3|
|% Area <60%||4|
Menthyl Anthranilate and Padimate O fluoresce when exposed to sunlight, meaning they absorb energy in the UVB range and re-emit it in the UVA range. If an active ingredient fluoresces, we increased the stability score by one point.
The scores for UVA, UVB, and fluorescence were added together to determine the overall stability score, which ranged from 0 to 9, and were then scaled to a range of 0 to 10.
Several inactive ingredients help prevent sun damage through mechanisms other than blocking UV rays. For example, a variety of antioxidants scavenges free radicals in cells (Klein 2005). In some cases, claims made for these ingredients are unregulated (Klein 2005), while in others, the SPF itself can no longer be predicted by the sun-blocking ability of the active ingredients alone (Stanfield 2005). In the later case, consumers are misled into believing they are receiving more protection than they actually are. For these ingredients, we attenuate the UVA and UVB scores as follows:
Table 6: Antioxidant scoring adjustments
|Raw score||Score category||Description|
|Attenuating score (improves UVB score by 10%)||Additional protection against UVB-induced damage||Anti-oxidants protect against UVB-induced radiation damage|
|Attenuating score (improves UVA score by 10%)||Additional protection against UVA-induced damage||anti-oxidants to protect against UVA-induced radiation damage|
Particle Size Assumptions for Mineral Sunscreens
The absorbance spectra for titanium dioxide and zinc oxide vary based on the size of the particle. Companies are not required to provide particle size information on package labels, leaving EWG with little information to determine the size and properties of the specific mineral ingredients used (FOE 2009, FDA 2007). EWG based the absorbance spectra on an average of the most likely particle sizes found products containing titanium dioxide and zinc oxide. The information was based on our review of particle size and surface coatings for zinc oxide and titanium dioxide found on the company websites of sunscreen manufacturers and formulators.
When the shortest dimension of the primary particles of titanium dioxide is 15 nm, it appears transparent on skin, but at 35 to 60 nm it becomes opaque (Schlossman 2005). All information we have amassed about 10 different titanium dioxide suppliers indicated primary particle sizes of 10 to 35 nm. Without clear regulatory guidelines, manufacturers and product formulators can claim they are using or not using nanoparticles without providing information to back up those claims. We assume that all UV attenuation-grade titanium dioxide sunscreens that appear clear on the skin use titanium dioxide with a mean primary particle size of 15 to 35 nm in the shortest dimension.
Table 7: Characteristics of sunscreen-grade titanium dioxide
|Titanium Dioxide Suppliers and Products|
|Supplier||Product||Crystal form||Primary particle size||Surface coating||Source|
|BASF||T-Lite SF-S||Rutile||30 nm*60 nm*10 nm, may aggregate into larger particles||Methicone||Gamer 2006|
|BASF||T-LITE SF||Rutile||30 nm*60 nm*10 nm, may aggregate into larger particles||Silica, Methicone||Gamer 2006|
|BASF||Uvinul TiO2||75% anatase/25% rutile||21 nm, agglomerate to 100 nm||trimethoxyoctysilyl||BASF 2006|
|Degussa||P-25||Anatase||21 nm||None, trimethyloctylsilane||Mavon 2007|
|EMD, Rona/Merck||Eusolex T-2000||Anatase||10 to 20 * 100 nm (possibly due to agglomeration)||Alumina, Dimethicone||NanoDerm 2007, SCCNFP 2000|
|EMD, Rona/Merck||Eusolex T-45D||Anatase||10-15 nm||Alumina/simethicone, oil dispersion||Sayre 2000|
|EMD, Rona/Merck||Eusolex T-AQUA||Anatase||10-15 nm||Alumina, water dispersion||Sayre 2000|
|ISK||TTO S-4||Rutile||15 nm||AHSA||Schlossman 2005|
|ISK||TTO S-3||Rutile||15 nm||Alumina||Schlossman 2005|
|ISK||TTO V-3||Rutile||10 nm||Alumina||Schlossman 2005|
|Kemira||UV Titan M170||Rutile||14 nm||Alumina, Methicone||Schlossman 2005|
|Kemira||UV Titan M262||Rutile||20 nm||Alumina, Dimethicone||SCCNFP 2000|
|Kobo Products||TEL-100||At least one dimension >100 nm, particles >100 when dispersed in ester||Aluminum hydroxide and silica||Kobo 2009|
|Kobo Products||MPT-154-NJE8||At least one dimension >100 nm||Alumina and jojoba esters||Kobo 2009|
|Kobo Products||TTO-NJE8||At least one dimension >100 nm||Alumina and jojoba esters||Kobo 2009|
|Sachtleben||Hombitec L5||Anatase||est. 15 nm (80-160 m2/g)||Silica, Silicone||Schlossman 2005|
|Showa Denka||Maxlight TS-04||35 nm||Silica||Schlossman 2005|
|Tayca||MT-100T||Rutile||15 nm||AS/AH||SCCNFP 2000|
|Tayca||MT-500B||Rutile||35 nm||Alumina||Schlossman 2005|
|Tayca||MT-100Z||Rutile||15 nm||AS/AH||Schlossman 2005|
|Titan Kogyo||Stt 65C-S||Anatase||est. 20 nm (64 m2/g)||None||Schlossman 2005|
Scientists estimate zinc oxide provides maximum UVB protection with particles sized 20 to 30 nm, and the typical sizes of zinc particles in sunscreen are 30 to 200 nm (BASF 2011, Cross 2007, Nohynek 2007, Stamatakis 1990). Compared to larger particles, smaller particles provide greater UVB protection but less UVA protection (Schlossman 2005). Particles larger than about 200 to 300 nm tint the skin white and are unacceptable to most consumers (BASF 2000).
By default, EWG has assumed that zinc oxide used as an active ingredient in sunscreens has a 140 nm mean primary particle size. This applies when manufacturers indicate they use Z-Cote or non-nano minerals.
Table 8: Characteristics of sunscreen-grade zinc oxide
|Zinc Oxide Suppliers and Products|
|Supplier||Product||Primary particle size||Surface coating||Source|
|Antria/Dow||Zinclear-IM 50AB||2740nm||C12-15 Alkyl Benzoate (and) Isostearic Acid (and) Polyhydroxystearic Acid||Antaria 2010, Dow 2011|
|Antria/Dow||Zinclear-IM 50CCT||2740nm||Caprylic/Capric Triglyceride (and) Glyceryl Isostearate (and) Polyhydroxystearic Acid||Antaria 2010, Dow 2011|
|Antria/Dow||Zinclear-IM 50JJ||2740nm||Simmondsia Chinensis (Jojoba) Seed Oil (and) Glyceryl Isostearate (and) Polyhydroxystearic||Acid Antaria 2010, Dow 2011|
|Antria/Dow||Zinclear-IM 55L7||2740nm||Neopentyl Glycol Diheptanoate (and) Glyceryl Isostearate (and) Polyhydroxystearic Acid (and) Cetyl PEG-PPG-10/1 Dimethicone||Antaria 2010, Dow 2011|
|BASF||Z-Cote||80 nm (30 to 200 nm)||uncoated or dimethicone||BASF 2010|
|Elementis||Nanox 200||60 nm (17 m2/g)||None||Schlossman 2005|
|Kobo Products||ZnO-C-12||At least one dimension >100 nm||Isopropyl Titanium Triisostearate||Kobo 2009|
|Kobo Products||ZnO-C-11S4||At least one dimension >100 nm||Triethoxycaprylysilane||Kobo 2009|
|Kobo Products||ZnO-C-NJE3||At least one dimension >100 nm||Jojoba esters||Kobo 2009|
|Kobo Products||ZnO-C-DMC2||At least one dimension >100 nm||Diemethicone/Methicone Copolymer||Kobo 2009|
|Sakai||Finex, SF-20||60 nm (20 m2/g)||None||Schlossman 2005|
|Showa Denka||ZS-032||31 nm||Silica||Schlossman 2005|
|Sumitomo Cement||ZnO-350||35 nm||None||Schlossman 2005|
|Tayca||MZ-700||10-20 nm||None||Schlossman 2005|
|Tayca||MZ-500||20-30 nm||None||Schlossman 2005|
|Tayca||MZ-300||30-40 nm||None||Schlossman 2005|
Source: Osterwalder, et al., 20098
The process of manufacturing a sunscreen that filters UVA rays is more challenging than making a sunscreen that prevents sunburn.
While many U.S.-made sunscreen products claim “broad spectrum” sun protection, implying protection from UVB and UVA rays, they actually vary substantially in the degree of UVA protection they offer.
Solar rays in the UVA wavelength from free radicals, which are highly reactive, excited, unpaired electrons that damage skin tissue.
Exposure to UVA radiation activates inflammatory cytokines and inhibits the skin’s immune response, possibly setting into motion another mechanism that facilitates the development of skin cancer. Sunscreens are typically much better at shielding the body from UVB rays than UVA rays.
For example, studies show that sunscreens reduce free radical generation by 50 to 75 percent,9,10 but products with SPF values above 15 reduce UVB by 93 percent or more.
The immune system protection of a sunscreen is more likely to correlate with its amount of UVA-shielding than its SPF.11 Therefore, an inferior sunscreen can successfully prevent sunburn without protecting the body from UV-related immune system suppression and skin cancer.
The FDA allows most sunscreens to claim they contribute to preventing skin cancer, while simultaneously reporting that the evidence to support this statement is contradictory.
The available evidence suggests that regular sunscreen use prevents squamous cell carcinoma. Scientists have not presented strong evidence that sunscreen use prevents basal cell carcinoma in part because regular sunscreen users may spend more time outside and get more sunburns and UV exposure than people who do not use sunscreen, cover up or spend less time outdoors.
Presently, the biggest question about sunscreen is whether it can help prevent melanoma, the deadliest form of skin cancer.
For decades, the rate of melanoma diagnoses has grown faster than that of any other kind of cancer, with no satisfying explanation for the rapid increase. In 1978, when the FDA initiated its sunscreen rulemaking, the National Cancer Institute reported that about 9,000 Americans had been diagnosed with melanoma.
This year, it estimated that more than 76,000 people will be diagnosed with melanoma.13
There is a complicated relationship between UV exposure and the risk of melanoma. Both UVB and UVA rays appear to contribute to melanoma risk.
Early life sunburns increase lifetime risks, as does the use of tanning beds, which subject people to strong doses of UVA rays. Only one prospective study supports the notion that sunscreen use prevents melanoma.
Set in Australia, this study found that daily use of an SPF 15 sunscreen, in addition to other sun protection strategies, reduced the number of new melanoma cases by 50 percent, and invasive melanoma by 71 percent.14
Usually increasing exposure to a hazard, whether a toxic chemical or UV radiation, leads to heightened risk. But this may not be the case for UV radiation and melanoma.
Instead, some studies indicate that regular sun exposure is associated with lower melanoma risk,15 as shown by its lower incidence in outdoor workers and people living in the American Sunbelt, compared to those living in cooler, northern latitudes.13
Because of complexities in understanding how UV light causes harm, scientists have not developed a universally accepted way to measure a sunscreen’s ability to protect people from melanoma or the long-term skin damage caused primarily by UVA rays.
The interim conclusion is that sunscreens should evenly filter light through the UVB spectrum, as well as the shorter and longer wavelengths in the UVA range (known as UVAI and UVAII).
The shortcomings of American sunscreens
Because the origins of melanoma are imperfectly understood, as is the role of UVA in other forms of sun-related skin damage, scientists have advocated that sunscreens provide “uniform protection” that strives to shield skin evenly through the entire UV spectrum.
The fabric is a model for ideal sun protection.
A basic cotton weave provides a “skin protection factor” of at least five across the UV spectrum.
While this number is much lower than the SPF advertised on most sunscreen bottles, sunscreen breaks down and washes off.
In contrast, clothing offers ample protection from sunburn and the best possible balance between UVB and UVA rays.16
The FDA regulates sunscreens as over-the-counter drugs. Sunscreen manufacturers are limited to using 17 FDA-approved ingredients in sunscreen,12but only eight of these chemicals are commonly used. Most approved ingredients filter only a portion of the UV spectrum. Sunscreen formulators typically mix one to six ingredients to create products that offer varying degrees of protection across the UV spectrum.
Sunscreen formulators typically mix one to six ingredients to create products that offer varying degrees of protection across the UV spectrum.
Sunscreen formulators typically mix one to six ingredients to create products that offer varying degrees of protection across the UV spectrum.
While many of the available ingredients provide good filtering of UVB rays, fewer cover the UVA spectra. Only zinc oxide and avobenzone effectively protect against shorter and longer UVA rays. To achieve high-SPF values, American sunscreen manufacturers must add UVB filters, which drive up the SPF value but result in a poor balance between UVA and UVB protection.
To achieve high-SPF values, American sunscreen manufacturers must add UVB filters, which drive up the SPF value but result in a poor balance between UVA and UVB protection.
Graphic 2 – Only two of the UV filters allowed in the United States provide meaningful UVA filtering.
The FDA requires sunscreen manufacturers to set product SPF values based on human testing, using a minimum of 10 human volunteers. The agency requires manufacturers to verify water resistance claims on products by testing sunburn after volunteers immerse themselves in a pool of water for 40 or 80 minutes.
Yet SPF values reported on product labels do not always match those predicted by other types of testing. In general, confirmation testing in laboratories suggests that many sunscreens offer far less sunburn protection than advertised on labels.
Minor variations in test conditions lead to big differences in SPF values. When products are tested outdoors in natural sunshine, the SPF is lower still.31
Consumer Reports tests sunscreens on human volunteers to confirm whether the SPF values are accurate. It uses a slightly different method than the FDA mandates for sunscreen companies, and it does not disclose the number of human test subjects used for each sunscreen.
Yet it chronically finds problems with sunscreens achieving far lower SPF values in its testing than the labeled values.
In 2015, Consumer Reports tests found notable variations in SPF values for mineral-only sunscreens, products that mixed minerals with non-mineral filters, and products advertising SPF values greater than 50+.32 In 2016, it reported similar shortcomings in SPF protection, with some notable issues for some mineral sunscreens and high-SPF products. It reported that non-mineral sunscreens had, on average, 86 percent of the labeled SPF value, and the SPF for mineral sunscreens was on average 64 percent of the labeled value33 (see Table 1 below).
The sample sizes were relatively small and non-random, with some overlap between 2015 and 2016. Although the methods used to test sunburn protection differed slightly, the reasons for the discrepancy between Consumer Reports and manufacturer’s reported SPF values are unclear.
Table 1: Consumer Reports 2016 test results – comparing in-vivo SPF testing with labeled SPF values
|N=||Meeting SPF Claim|
(75% or Greater of
Reports SPF vs.
Consumer Reports found that mineral products with similar concentrations of active ingredients had notably different SPF values in its tests.
For example, the 2016 report examined seven mineral sunscreen products with relatively low concentrations of both zinc oxide and titanium dioxide (ranging from 3.7 percent to 7 percent of each mineral). Package labels reported SPF values of 30 to 50+.
Two of seven products met the labeled SPF value while the remaining three offered only 16 percent to 50 percent of the advertised SPF.
The Consumer Reports investigation highlights problems with the FDA test methods for SPF values. SPF testing conducted by manufacturers should match results of testing done by another laboratory. Replications should produce consistent results for the same product.
Where there is person-to-person variation, the lowest reported SPF values should be listed on product labels rather than discarded as outliers, as is currently allowed in FDA tests.
Ultra-High SPF claims
EWG is concerned about the continued sale of ultra high-SPF sunscreens. The FDA proposed to cap SPF values at 50+ in 2011, calling ultra-high SPF values “inherently misleading.”
The FDA proposed to cap SPF values at 50+ in 2011, calling ultra-high SPF values “inherently misleading.”
SPF values are capped at 50+ in Europe, Australia, Canada and Japan.
There is little evidence to indicate that higher SPF products provide any additional health benefits. To the contrary, some studies suggest that high-SPF products may mislead consumers into believing that they are fully protected from sun damage.
One result is that people using sunscreens with higher SPF values risk excessive exposure by spending more time in the sun.17
The main argument in support of high-SPF products is that since people do not adequately apply and reapply sunscreen, higher-SPF products may compensate for the inadequate application.
Yet when people apply a thin layer of a high-SPF sunscreen, the amount of UVA protection decreases more than that of UVB.
Another factor behind the FDA’s proposal to cap SPF values at 50+ is that human test methods cannot reliably measure differences between ultra-high SPF values.
The FDA’s method tests sunburn on small areas of volunteer’s skin. Each site is treated with just one milligram of sunscreen.
Tiny differences in the amount of sunscreen used or application thickness could result in major differences in the calculated SPF. These errors would be most dramatic for high-SPF products.
In-vitro testing also suggests shortcomings in sunburn protection for high-SPF products. In 2009, Jay Nash of Procter & Gamble tested 330 U.S. sunscreens and submitted this data to the FDA to assess the potential effects of the sunscreen rules proposed two years earlier.40 Nash measured the amount of UV that passed through a layer of sunscreen spread on acrylic slides, and found that high-SPF products typically offered less UVB shielding than touted on their labels. Like the EWG model, products with the highest labeled SPF values performed the worst. In Nash’s tests, products with SPF values of 70 and higher exhibited the greatest differences between labeled and estimated SPF. The measured SPF was less than half of the labeled value for 12 of the 14 products he tested.
These findings suggest that manufacturers may be adding ingredients to boost the SPF values on labels. These ingredients do not change the UV-transmission through a slide in the laboratory, which implies that they do not prevent UV radiation from striking the skin. Rather, they would use other mechanisms to reduce the presence of sunburn once UV strikes skin. The FDA should investigate the use of inactive SPF boosters, their performance, stability and ability to protect skin from other types of UV-related skin damages.41
UVA or “broad spectrum” protection
By all accounts, UVA protection remains a challenge for U.S.-made sunscreens. EWG analysis suggests that many products bearing the “broad spectrum” label could not be sold in Europe, where UVA protection must be at least one-third as strong as the labeled SPF value of the product. According to our modeling, only 3 percent of beach and sport sunscreens would fail the FDA critical wavelength test for broad spectrum protection. Yet we estimate that 49 percent of the more than 750 beach and sport sunscreens in our 2016 database pass the FDA broad spectrum test but would not pass the European UVA test.
Our findings are in line with Procter & Gamble’s 2009 product survey, which reported that 68 percent of sunscreen products manufactured for that year would pass the FDA’s Critical Wavelength test for broad spectrum protection. The company estimated that only 44 percent could be sold in Europe.40 Without a system that rewards superior performance, American manufacturers have little motivation to improve the UVA shielding of their products.
Higher-SPF products provide less balanced UVA protection in relation to UVB protection. Analyzing data submitted by Procter & Gamble, EWG determined that the average UVA Protection Factor was 50 percent of the measured SPF for products with labeled SPF values between 30 to 50, but decreased to about 33 percent for the products with labeled SPFs over 60.
This decrease in UVA protection relative to that of UVB is, in a part, due to FDA rules which limit the use of ingredients that filter UVA rays. For example, avobenzone and zinc oxide are the only allowed ingredients that provide good UVA shielding. Nearly every non-mineral product with SPF of 30 or higher uses avobenzone at the maximum concentration of 3 percent. As the SPF in these products increases, the UVA protection does not increase proportionally.
Recently, British researcher Brian Diffey evaluated four SPF 50 and 50+ sunscreens sold in the U.S. and four sold in Europe. The European products featured modern UVA filters not allowed in the U.S. He found that the U.S. sunscreens allowed an average of three times the UVA rays to pass through to skin, compared to those sold in Europe.42 We would expect the UVA balance to be even worse for U.S. sunscreens with SPF values greater than 50+.
Yet American sunscreen manufacturers may not be able to improve UVA protection until the FDA caps SPF values and approves the new, modern filters used in Europe. In-vitro tests by Steven Q. Wang of Memorial Sloan Kettering Cancer Center found that only products with Tinosorb and Mexoryl SX achieved the highest rating on a proposed “spectral uniformity” test.43
Graphic 4 – High-SPF European sunscreens block more UVA radiation than U.S. products. Tests of eight SPF 50 or 50+ sunscreens from the U.S. and Europe.
Source: Diffey, 201543
Section 4: What no testing measures – the real-world performance of sunscreen
A wealth of evidence suggests that today’s sunscreens widely overstate the skin protection they offer from UV damages.
SPF values on sunscreen labels are similar to the gas-mileage estimates on new cars: They represent ideal performance under unrealistic test conditions, but often misrepresent outcomes in the real world. Real-world UVA shielding and balance are harder to gauge, and subtler skin damages may show up only decades later.
This problem can result from a variety of factors:
A) SPF is tested using an unrealistically thick coat of sunscreen, far more than people use in the real world.
The test requirements for sunscreen specify application of an unrealistically thick coating of sunscreen to the skin surface or test slide. This would be the equivalent of a family of four using a four-ounce bottle of sunscreen for a two-hour visit to the beach. In reality, people apply far less sunscreen to their skin and do not reapply it often enough to achieve the advertised SPF. UV protection does not follow a linear relationship, meaning that if you apply half of the recommended amount you get less than half of the labeled SPF protection. Under-application of sunscreen results in far less sunburn protection and UVA protection. A thinner coating of sunscreen diminishes UVA protection slightly more than UVB protection.44
SPF testing by companies evaluates a similarly thick coat of sunscreen on all volunteers, but in reality people apply products differently based on packaging and skin feel. Thicker pastes such as stick sunscreens and mineral formulations feel heavier on the skin. People may believe that they have applied a thicker coating than is the case. Water/oil emulsions form the most uniform layer on skin. Aerosol sprays are dispensed in tiny droplets that form the thinnest film on skin, with more gaps.45 EWG is concerned that these qualities make it easier for sunscreen users to miss areas during application. In 2011, the FDA asked manufacturers to submit data proving that aerosol sprays provided a thick enough coating to impart good skin protection.12
A recent industry-funded study of 52 consumers found that people using sunscreen lotions applied an average of 1.1 mg/cm2 to their forearms, while those using sunscreen sticks applied far less, at 0.35 mg/cm2.46 Sprays were tested by different methods. Volunteers were asked to spray a “normal” amount onto a diagram of a person, and the quantity of sunscreen applied was measured by weight. Researchers reported that the volunteers using aerosol sprays applied average spray thickness of 1.6 mg/cm2. EWG cautions that testing with a diagram instead of a person probably overestimates real-world application of the sunscreen spray.
The same study reviewed other sunscreen application research, which reported a range of application rates from 0.11 to 1.48 mg/cm2, all far less than the 2.0 mg/cm2 specified in SPF tests.46 One study found that people applied mineral sunscreens in thinner coats than chemical sunscreens, a pattern they attributed to the denser, thicker nature of mineral products.47
These studies raise a fundamental question: Why not label SPF values based on people’s application behaviors in the real world and communicate a more accurate message about sunburn protection?
B) Sunscreens commonly include ingredients that affect skin reddening and UV protection but are not listed on product labels as “active ingredients.”
Tests of real world sunscreen along with EWG modeling suggest that sunscreen manufacturers are commonly adding unregulated ingredients to sunscreens that can have major effects on SPF values. Many of these ingredients may decrease skin reddening, but it is not clear whether they also reduce other types of UV damages. SPF boosters limit skin redness in human studies, but do not necessarily block UV light from striking the skin as measured by spectrophotometry or in EWG modeling.
Ingredients that act as skin antioxidants and anti-inflammatories can reduce sunburn. Other ingredients, such as hollow spheres, can boost the UV protection of active ingredients by scattering UV rays.
UV scattering agents bend UV rays so they pass through a thicker layer of sunscreen and have more opportunity to be absorbed or scattered by active ingredients.48 These substances should provide a similar benefit as a thicker layer of sunscreen, and affect both UVA and UVB rays. Dow’s Sunspheres™ are hollow spheres approximately 250 nm in size made of styrene/acrylates co-polymer (i.e., plastic), that the company claims can boost UV protection by 60 to 70 percent.
Anti-inflammatories inhibit skin reddening. EWG is concerned that many mask the immediate signs of skin damage without offering greater skin protection from UV-damage. French sunscreen researcher Céline Couteau wrote:
The continuing anti-inflammatory effect, without reapplying the product at all, gives the user a sense of false security on the one hand, and on the other hand is likely to encourage them to prolong time of solar exposure.49
In 2013, Robert Sayer and John Dowdy petitioned the FDA to ban five active ingredients from two families of UV filters because they appeared to inhibit skin reddening but not necessarily impart protection from other UVB damages.50 The petition cites one active ingredient, trolamine salicylate, which is not widely used in sunscreen but is marketed in anesthetic creams. A much more common ingredient, oxybenzone, is used in approximately 40 percent of sunscreens in EWG’s 2016 database. Oxybenzone was originally patented for the ability to reduce skin redness when applied after sun exposure.51 Other widely used active ingredients, including homosalate and octisalate, appear to offer similar anti-inflammatory effects.
Other ingredients common in sunscreens have anti-inflammatory effects but do not change the amount of UV rays that hit skin. These include common botanical extracts from licorice, chamomile and aloe, among others. Céline Couteau found that the addition of bisabolol, a component of chamomile, glycyrrhizate from licorice, and allantoin had potent anti-inflammatory effects on skin in laboratory studies.52 The anti-inflammatory effect can persist for more than six hours following application.49 Couteau has also shown a lack of relationship between the SPF value and anti-inflammatory activity of sunscreen.49
Some researchers dispute these concerns about ingredients with anti-inflammatory effects.36,53 They cite studies showing that, in addition to inhibiting sunburn, high SPF sunscreens protect against biological markers of UV skin damage.30,54
Antioxidants such as vitamin A, C and E, and botanical extracts are common in sunscreen. They are added based on the theory that these substances may impart some additional skin protection by “quenching” or reducing free radicals caused by UVA rays,55 which damage skin DNA, proteins and lipids. Some studies find that the addition of antioxidant vitamins and botanicals like caffeine and echinacea have reduced skin damages.56
However, other studies have found that antioxidants have few biological effects.27One critical factor is the difficulty formulating a lotion with antioxidants that does not break down in storage or when exposed to sunlight.56 While antioxidants can stabilize active ingredients like avobenzone in products, UV rays can also break down antioxidants, sometimes forming harmful byproducts. For example, research indicates that vitamin A additives, which are common in sunscreen, may speed the development of tumors and lesions on sun-exposed skin.57
EWG has asked the FDA to examine the use of SPF boosters and other inactive ingredients in sunscreens.41
Poorly formulated or old sunscreens may separate, making it impossible to coat skin evenly.
To work effectively, sunscreens must form a stable film on the surface of the skin. The more uniformly UV filters are dispersed on the skin’s surface, the better protection they confer. Formulation is more challenging in higher-SPF sunscreens in which the concentration of active ingredients can approach 25 percent in mineral products, and go up to 40 percent in non-mineral products sold as lotions or sprays.45 Sunscreen formulators use a variety of ingredients such polymers to try to ensure that the UV filters are dispersed in an even, stable film on the skin. They must balance a high concentration of active ingredients optimally dispersed on the skin against consumer preferences for a light, spreadable formula.
Water- and sweat-resistant formulations use polymers or other technologies to resist degradation. EWG’s UV modeling and in-vitro sunscreen testing do not assess these qualities in sunscreen formulations. The FDA requires sunscreens marketed as water-resistant to submit third-party verification of this claim. The FDA does not require manufacturers to prove that aerosols marketed for use on wet skin provide the sun protection they claim. By contrast, Canada requires companies to submit data to justify claims that a product works on “wet” or “sweaty” skin.58
Over time, cycles of heating and cooling can cause sunscreen ingredients to separate or clump in the bottle or tube. These products will not provide a thick, uniform coating on the skin surface, and will lead to poor skin protection and sunburn. Some sunscreen labels instruct users to shake the product before applying. Others are stamped with expiration dates.
Some sunscreens contain active ingredients that break down in the presence of UV rays.
Avobenzone, the primary UVA filter in non-mineral sunscreens, can degrade when exposed to solar rays. Manufacturers improve stability by mixing avobenzone with other active ingredients, such octocrylene or inactive ingredient stabilizers, to slow UV degradation, with varying degrees of success.59
EWG’s UV protection model rates photostability of the combinations of active ingredients disclosed on product labels. However, EWG’s methodology does not assess the actual degree to which specific products break down in the presence of UV rays.
Mineral-only sunscreens are the most stable and should not lose their ability to filter UV rays when they are exposed to UV rays. In spite of that, some forms of titanium dioxide and, to a lesser extent zinc oxide, can be activated by UV rays and form free radicals that damage surrounding cells. Sunscreen manufacturers generally use minerals with an inert coating that reduces the potential for photoreactivity. These coatings must be stable in the sun.
EWG’s review of information from mineral sunscreen suppliers suggests that the forms available for U.S. sunscreen are coated to reduce photoreactivity, but unlike European regulators, the FDA does not set specifications for mineral ingredients in its sunscreen rules.
Sources for this article: