Locogringo.com

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Yesterday's post on sunscreens got me wondering about sunscreens, so I did a brief search to try to figure our "What the heck is going on?" If you are confused about sunscreen, hopefully this will help you. If you are a dermatilogist or an envrionmental epidemiologist, perhaps please correct me where I'm wrong.

Sunscreens
Sunscreens (sunblock) are ointments, creams, sprays, salves (I always liked that word) used to protect the skin from the harmful rays of the sun. These harmful rays are ultra-violet rays with wavelengths between 380 to 315 nanometers (UVa) and 315 to 280 nm (UVb). UVb rays are reportedly the cause of painful sunburns. UVa rays are reported in some sources as not causing sunburn but both rays can cellular damage resulting in premature skin aging and or skin cancers.

Sunscreen works by either scattering the light before it hits the skin or by absorbing the sunlight. Scattering compounds used are the opaque mineral titanium dioxide (TiO2) and Zinc Oxide (ZnO).

Absorption of UV rays is affected by aromatic compounds that are conjugated to a carbonyl group. When exposed to UV radiation these compounds adsorb the UV rays and convert the light energy into radiant heat energy. The first widely marketed compound to be used as a sunscreen was para-amino-benzoic acid (PABA) however, it was found to be very harsh, causing skin rashes and allergic reactions. Most sunscreens on the market are PABA free. The following are the United States Food and Drug Administrations (USFDA) allowable concentration of active ingredients in sunscreen:

Class PABA & PABA Esters
 p-Aminobenzoic acid (PABA) up to 15 percent.
 Padimate O up to 8 percent.

Class Benzones
 Avobenzone up to 3 percent.
 Dioxybenzone up to 3 percent.
 Oxybenzone up to 6 percent.
 Sulisobenzone up to 10 percent.

Class Cinnamates
 Cinoxate up to 3 percent.
 Octocrylene up to 10 percent.
 Octyl methoxycinnamate (Octinoxate) up to 7.5 percent

Class Salicylates
 H'om'osalate up to 15 percent. (Note appostrophes inserted by me because LocoGringo uses a xenophobic filter that prohibits the Greek root of 'same')
 Trolamine salicylate up to 12 percent.
 Octyl salicylate up to 5 percent.

Others
 Menthyl anthranilate up to 5 percent.
 Phenylbenzimidazole sulfonic acid up to 4 percent.

Light Blockers
 Titanium dioxide up to 25 percent.
 Zinc oxide up to 25 percent.

It should be noted that avobenzone is the only sunscreen compound allowed by the European Union.

Environmental and Health Considerations

Most sunscreen consumers are concerned that the sunscreen they choose to use is environmentally “safe”. Unfortunately this is where the issue gets very confusing. Part of the confusion is because the sunscreen market is a large and lucrative. Branding and market positioning are extremely important in maintaining sales. It is easy to see why marketers use fear when marketing a product that some dermatologists will endorse as preventing skin cancer or premature aging. When faced with claims from marine environmentalists that over use of brand X is killing the environment you can market your brand as “safe”. Regardless of how you market your sloppy cream, spray, or salve, the consumers don’t really know the truth behind the “claims”. Factual safety claims rely on prolonged exposure to various environments at various concentrations and with considerations for how frequently cancer will be encountered (slope factor) and how frequently adverse health problems will be encountered (risk factor). It all comes down to statistics. Which in the words of Mark Twain “there are lies, damnable lies, and then there are statistics”. And all of the claims I read had NO supporting data.

My first search was for sunscreen environmental health. Results from “Googling” were primarily the resultant USFDA ban on combining sunscreen with DEET. The reason was that the continued application of sunscreen may lead to overexposure to DEET. Additionally there were a few articles about the environmental fate of DEET in aquatic life forms because people might be using the combined product when swimming. But the bottom line is since the product is no longer available so it is not a valid issue at this time.

What then is the story behind “eco-friendly” or “environmentally safe” and “all natural” formulations? Complete and total bunk is my read on it. Pick your market (your target consumer) and make your claims. That is the only way to sell snake oil.

“But Billiam, how can you say such awful things?”
Here’s a list of “all natural” herbal sunscreen ingredients...
Titanium dioxide, water, sunflower oil, vegetable glycerine, green tea extract, sweet almond oil, coconut oil, jojoba oil, tocopherol (vitamin E), cocoa butter, orange blossom oil, rice bran oil, lanolin oil, xanthan gum, sodium hydroxymethyl glycinate, eucalyptus oil, lecithin.

Then again, the “eco-friendly”, and “environmentally safe” formulations go out of their way to say “Oil Free” but do not say WHAT they are using for a vehicle. Some do list the active ingredients…octinoxate (7.5%) padimate O (5%), oxybenzone (5%) and octyl salicylate (2.5%) (“I feel much better now knowing that the crud is Oil Free”). Again check for yourselves, you will find that most sunscreens will tell you what is DOESN’T contain more often than what it DOES. (Oh and a claim you will NEVER see, “Guaranteed safe for the environment, we’ve done extensive testing on laboratory bunnies and baby turtles to prove it”)

Safety Claims…or rather “unsafety” claims.

OK so to protect the reef and the aquatic environment we should be using oil-free, at least that’s what the “dolphin huggers” seem to claim. Except that, again, there are "claims" that the benezone and cinnamate classes of compounds (and a standard ingredient in the adsorbing sunscreens) are estrogen disrupters. That is, these "gender bender" compounds will cause all kinds of sexual confusion and dimorphism in untold numbers of creatures. (Then again maybe that is what the sexually dimorphic Stoplight parrot fish needs to get it’s mind right). So scratch adsorbing sunscreens off the "safe" list.

“At least the scattering compounds are safe, right Billiam?”
Wrong! Again, there are more claims that nanoparticals (the tiny microscopic sizes) of the titanium dioxide and zinc oxide pigments will accumulate in fish and are toxic to fish. Again these are claims. The chemistry of waters can vary greatly as will the mobility of dissolved or suspended particles. Further investigation shows that zinc oxide, is a listed compound under NIOSH (National Institute for Occupational Safety and Health) and the exposure to zinc oxide DUST is 5 milligrams per cubic meter (however is suspended in a cream it is not airborne, but then again, has any one measured the airborne exposure after drying?) Furthermore, if this is nasty in your lungs, what is it to a fishes gills (it does not need to be dried to become water borne).

So what does Billiam use? Oil free sunscreen, SPF 45 or 30 (minimum), water proof/sweat proof...And I do not endorse any manufacturer. And if you can find the “sport” formulation that uses isopropyl alcohol for a vehicle, grab it. Getting a “beer buzz” off your sunscreen it the best way to start the day! Buy it before you go, it’s cheaper here. Put it on first thing in the morning and let it soak in. Re-apply as necessary, but try to stay out of the sun during mid-day...And look both ways before you cross the street.

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One you drink the other you rub on?