#41 Sunblocks and Sunscreens; Part Two of Two

S.afety O.n S.ummits
By: Rick Hartman

#41 Sunblocks and Sunscreens; Part Two of Two

During the Middle Ages, probably one of the biggest mistakes was not putting on your armor because you were just going down to the corner.” Jack Handy

Archaeologists recognize early Egyptians used natural formulas for sun-blocking, whereas modern man patented our first products in the mid-1930’s. Sunscreens are applied externally to protect the skin from harmful effects of the sun. Using them prevents sunburn, decreases the risk of skin cancer, delays premature skin aging, and decreases the effects of sun-photosensitivity caused by prescription antibiotics and some medications. The active ingredients within sunscreens work to prevent the sun’s ultra violet (UV) rays from penetrating the deep layers of the skin either blocking, absorbing or reflecting off the UV rays. There are three types of ultraviolet rays, UV-A which goes deep into skin and causes wrinkles and age spots, UV-B which burns skin and eyes, and UV-C, the strongest and most dangerous rays, which are blocked out by the Earth’s ozone-layer.

Two points: the more expensive sunscreens do not necessarily translate into better in quality and presently, there is no FDA-approved rating system that measures UV-A protection levels. The Sun Protection Factor (SPF) displayed on the label refers to a product’s ability to effectively screen/block the sun’s harmful UV-B rays and can range from SPF-2 to as high as SPF-70 “+”. The higher numbered SPF indicates its ability to provide greater sunburn protection. The American Academy of Dermatology now recommends the minimum SPF requirement to be: “30”. The SPF number is multiplied by the number of minutes it takes unprotected/exposed skin to sun burn. Thus SPF 30 “times” the 10 minutes unprotected skin will burn, equals 300 minutes (five hours) of protection with that SPF 30 product. The SPF-15 rated product simply means one can be in the sun 15-times longer than without sunscreen before a sun-burn can occur. Products rated SPF-2 can be expected to absorb/block/reflect 50% of UV-B radiation, SPF-15 will do 93%, and SPF-30 will do 97%. However all of these examples are a generalization, as individuals with fair skin will react differently than those with dark skin. For fair skin individuals, who sunburn easily, selection of a higher numbered SPF product providing additional protection is in order, as well as reapplications every two hours. Sunscreens do not protect against all of the sun’s radiation, so by simply applying sunscreen, it does not mean one can stay out longer in the sun. However, in our hobby, here is the huge challenge we face: the 23 hours of daylight on Denali, where no shade exists, on that mountain sun avoidance becomes impossible!

No one sunblock/sunscreen and no single ingredient can block the entire UV spectrum. As consumers we do need to check the product labels! Sunscreens use chemical based agents; their special ingredients absorb/block/reflect the UV-B ray energy and stop penetration into the skin. Recent sunscreen products now employ several chemicals to attain the coveted “Broad Spectrum” status granted by the FDA. Sunblocks are physically based. They were the first “Broad-Spectrum” products, using the ingredients “zinc-oxide” and “titanium-dioxide” designed to block, reflect away or scatter both UV-A and UV-B radiation. However, the physical traits of these first broad-spectrum sunblock products were unacceptable to many users. Cosmetically, they were messy, visible, and did not easily wash off. However, the newer products have taken to touting brightly colored preparations that have become popular with recreating youth. These first physical-based sunblocks remain highly recommended for those who have unusual sensitivity to UV radiation and, as a plus, they rarely cause skin irritation.

The two active mineral ingredients used in the first sunblocks were zinc-oxide and titanium-dioxide; and both are approved by the FDA. This is the white stuff we have all seen on the life-guard’s nose and forehead. Modern chemistry has allowed manufacturers to effectively reduce the size of these two minerals into nanoparticles (a millionth of a meter); termed as: “micronized”, “nanosized” or “ultrafine”. By this reduction in size, nanoparticles allow more even coverage. Studies have shown both micronized zinc-oxide and regular zinc-oxide offer very effective UV protection by reflecting sunlight before it reaches the skin. Regular sized zinc-oxide and titanium-dioxide are non-toxic, non-irritating and highly effective sunblocks. The current trends of nanoparticles has eliminated the unappealing stark white color, but such a reduction in size has allowed the concern to be raised that nanoparticles could potentially penetrate through skin and cell walls, to be carried through-out the body. However, there is no clinical evidence of this presently. Labeling is not required at this time to identify nanoparticles in product formulas. If your sunscreen/sunblock of choice has either zinc-oxide and/or titanium-dioxide and goes on clear: suspect nanoparticles in the formula. Scientific studies show micronized zinc-oxide and titanium-dioxide can penetrate the outermost layers of the skin; however it does not get to living tissue or the blood stream. Micronized zinc-oxide and titanium-dioxide are highly toxic if inhaled, becoming a potential health problem, thus some experts advise against powders and spray which contain them. Lotions and creams are considered safer, as inhalation is unlikely. Posted on the www, micronized zinc-oxide and titanium-dioxide are “not a risk to human health”; but the jury remains out on this concept, as some www sites do recommend risk avoidance.

As of mid-2012, the FDA implemented new regulations prohibiting manufacturers from using the terms “Sunblock” (as a descriptor), “waterproof” or “sweatproof”, “instant protection”, any claim of “protection for more than two hours” and SPF values must be no higher than: “50+” on any across-the-counter sunscreens. There is no evidence proving products with 55 to 100”+” SPFs provide greater protection, thus the FDA addressed this false sense of safety likely held by consumers.

Do not be misled; no sunscreen is waterproof or perspiration-proof. If labeled “water-resistant” it will maintain the SPF level for 40 minutes of water immersion. If labeled “very water-resistant” the SPF level will be maintained for 80 minutes. By toweling yourself dry you wipe away sunscreen. So reapply frequently for continued protection. Certain products may be ineffective, as their ingredients may break down upon exposure to the sun. It is recommended by the American Cancer Society consumers choose the “Broad Spectrum” products; they have protective ingredients to combat both UV-A and UV-B rays. The “Broad Spectrum” selections should contain any or all of the “big four”: zinc-oxide, titanium-dioxide, avobenzone or mexoryl.

There are various forms of sunscreens: butters, cream, gels, lotions, oils, ointments, pastes, sprays, sticks, and lip balms. The oil-based products contain insufficient amounts of sunscreen agents and are usually rated at SPF -2 or less. The safety of spray-on products is being reviewed by the FDA. Sprays are suspected of providing less SPF protection than label claims and pose a danger if inhaled or used around heat sources. Always use caution; as spray types are flammable. Do not use spray applicators or alcohol- based sunscreens near heat, open flames or while smoking! To avoid inhalation, spray onto your hands and then apply to your upper body areas. All sunscreens are only for use on the skin, lip balms are only for lips, and none of the products should be applied onto mucous membranes. Read the individual product label and comply with the directions.

Products that contain PABA (para-aminobenzoic acid), lisadimate, padimate or roxadimate may discolor and stain clothing, upholstery of vehicles or furniture. PABA can react with sensitive skin. If you develop a rash, the likely culprit is PABA. Other rare ill-effects of PABA are slowing/shortness of breath, irritations and swelling with eyes, ears, nose, throat, skin nausea or vomiting, intestinal discomfort, dizziness and nervousness. If you develop any of these symptoms, stop using the product and seek medical attention. Consider, at high altitude, most of these reactions can be life threatening. Always test a new sunscreen product by first applying it onto a small patch of skin, as a skin reaction (rash) could develop. If the sunscreen gets in your eyes, rinse thoroughly with water. Avoid applying sunscreen to damaged or broken skin. Finally, sunscreen should not be applied on infants less than 6 months of age. Infants, if outdoors, should remain out of the sun and wear protective clothing (hats, long sleeved shirts and pants). For children older than 6 months, use a SPF of 15 or higher and avoid the alcohol-based sunscreens.

Use sunscreen by generously applying it to all exposed skin: the ears, scalp, face, (around eyes), the neck, hands and forearms. This should be done at least 20 minutes before going outside and reapplied every two hours. There is no such thing as “too much”. The best description for how much volume to apply is: an ounce, appearing as “a golf ball-size” portion of lotion in your palm. Sunscreen should be used even on cloudy days, as 80% of UV radiation will pass through clouds. If on snow, ice or water, reflected solar radiation will burn the inside of your nose and ears. So here is the challenge: the inside of those orifices will get burned, however sunscreen should be avoided on/in mucous membranes! At high altitude, our panting while on snow and ice will often result in a sun-burned tongue and roof-of-the-mouth (this feels as if they were burned by a hot beverage), preventing that occurrence becomes yet another challenge. It’s nearly impossible to protect these potential sunburn locations; perhaps a scarf, worn like a train robber, is the solution.

The FDA maintains the ingredients within sunscreens are safe and the benefits of regular use outweigh any potential risk. These ingredients have been used for many years and the FDA believes there is no reason to suspect the chemical ingredients are unsafe for consumers. However, buyer beware, the FDA does not strictly supervise its own labeling regulations. So now to the “fine print” which always seems to go along with the “better living” enjoyed through chemistry. Putting chemically based sunscreens on our skin is a classic damned if you do and damned if you don’t situation. The issue must be openly shared. The quandary: ounces of carcinogen containing lotion smeared on our skin versus the “amount” of UV radiation exposure received. There is a counter-concept concern that overzealous use of sunscreens may be partly to blame for the rise of melanoma and other cancers. Chemicals in some sunscreens are known to accumulate within our bodies, this because the human organism is not naturally capable of eliminating or using them in an efficient manner. Here are a few facts: our human skin has evolved to effectively keep out toxins, but some chemicals can pass through, and applying sunscreen does more good in protecting skin’s DNA against UV radiation than any potential chemical harm claimed by internet postings. At this time, testing on humans has produced mixed results, there is no clinical evidence to prove or disprove the below chemical side-effect concerns to human DNA. Know: S.O.S. struggles to remain neutral in this debate. After all, the chances are apparently slim regarding the chemical considerations, but certainly not so in the skin cancer realities. One fact is solid: UV radiation is bad for our skin. Thus, the reader must make the final decision and do what is most comfortable.

The most common active chemical ingredients used in sunscreens sold in the United States are: Oxybenzone, Octisalate, Octyl methoxycinnamate (Oxtinoxate), and Avobenzone (Parsol 1789). Here are their negatives. Oxybenzone is claimed to penetrate the skin and cause sensitivity to light; some scientists argue this chemical maybe a contributing factor in the recent rise in melanomas among sunscreen users. Other studies are claiming that Oxybenzone behaves much like the hormone Estrogen, leading to a suggestion it could be a factor in breast cancer. The CDC discovered Oxybenzone was present in 96.8% of the urine samples they tested. Being only rubbed on our skin, it apparently gets around! Avobenzone (Parsol 1789) has been recognized to penetrate skin, but so far, most studies have shown it to be non-toxic. There is the claim that Avobenzone (Parsol 1789) becomes unstable when exposed to UV rays and more easily so, when mixed with other sunscreen active ingredients.


Active Ingredient Type and percent Type of radiation Blocked or Absorbed Identified Toxicity Class
Avobenzone (Parsol 1789) 1 to 3% UV-A Possible carcinogen, if ingested.
Homosalate 6 to 15% UV-B Endocrine disrupter.
Octocrylene 0.8 to 10% UV-B Bio-accumulative in wildlife, liver issues and carcinogenic.
Octyl methoxycinnamate (Octinoxate) 7.5% UV-B Hazard ranking: moderate to high. Accumulates in the body, disrupts liver, the endocrine system, and is a carcinogen. It is restricted in Japan.
Octisalate 2-5% (Octyl Salicylate 3%) UV-B Broad systemic effects in animals at moderate doses.
Oxybenzone 2 to 6% (6Benzophenone-3 5%) UV-B, UV-A Hazard rating: High. FDA approved in 1978 for 6 months and older humans. No data of significant health or hormonal problems in humans. But claimed carcinogen and contributor to vascular disease. May affect brain and nervous system in animals. CDC studies show 98% of American bodies are contaminated.
Titanium-dioxide 2 to 8% UV-A and B broad spectrum Carcinogen when in nanomaterial form.
Zinc-oxide 3.8 to 9.1% UV-A and B An inorganic compound used in broad spectrum blocks. Evidence of reproductive toxicity. Bio-accumulative in wildlife.


Active Ingredient Type and percent Type of radiation Blocked or Absorbed Identified Toxicity Class
Aminobenzoic acid UV-B Carcinogen; implicated in cardiovascular disease.
6Benzophenone-2 UV-B, UV-A Hazard rating: High. Not approved in US due to strong evidence of hormonal disruption in humans and wildlife.
Cinoxate UV-B Evidence of skin toxicity.
Dioxybenzone UV-B, UV-A Strong evidence of skin toxicity and carcinogen; hormone disrupter. Found in waterways, soil and air. A “gender bender” in animals.
Ecamsule (“mexoryl SX”) (terephthalylidene dicamphor sulfonic acid) UV-A/lesser of: B Considered safe, not mutagenic in vitro studies. Water soluble. Patent held by L’Ore’al since ‘82. FDA approved in 2006.
Menthyl anthranilate UV-A  
Mexoryl XL (drometrizole trisiloxane) UV-A/B European approved. Not FDA approved for over-the-counter U.S. sunscreens. Oil soluble. Patent held by L’Ore’al.
PABA (para-aminobenzoic acid) UV absorber and filter Hazard rating: High. Known history of allergic reactions; poisoning can occur with some lotions. A known carcinogenic. FDA classifies it: “safe for general or specific, limited use.”
Padimate O UV-B Carcinogen. Related to PABA (above). Suspected of DNA damage. But all studies are inconclusive.
Phenylbenzimidazole sulfonic acid UV-B Carcinogen.
Retinyl palpitate Protects against skin aging A form of vitamin A, found naturally in skin. No evidence of increased risk of skin cancer. One form: “retinoids” used for decades to prevent skin cancer for those of high risk.
Sulisobenzone UV-B, UV-A Strong evidence of skin toxicity, affects sense organs in animals.
Trolamine salicylate UV-B  

Caution is advised with all tanning agents (both sunless and sunscreen types) as potential side effects and reactions can occur when combined with other medications (even over-the- counter meds). Avoid using them while pregnant or breast feeding or with knowledge of personal allergies to anything else.

Once more, kudos are extended for Bill Jacobs’ continued outstanding editorial efforts on these S.O.S. articles. A very special expression of total gratitude is extended to Denise Spartonos and Lisa Quale of the University of Arizona Cancer Center‘s Skin Cancer Institute; their devoted assistance in this article series was a very critical component!

For additional information: http://www.aad.org/spot-skin- cancer