05.27.08
Nanotechnology and Sunscreens
In the event that there are potential risks associated with nanoparticle use, Friends of the Earth has recently begun a campaign advising the public to avoid using products that contain them. Their argument is that since the physics of nanoparticles is different we can’t predict their behaviour. They quote a 2004 report by the United Kingdom’s Royal Society, which recommends that “ingredients in the form of nanoparticles should undergo a full safety assessment by the relevant scientific advisory body before they are permitted for use in products.”
(Please see Friends of the Earth press release at this link for more details) http://www.foe.org/new/releases/may2006/nanorelease5162006.html
FOE points out that many companies continue to use nanoparticles in the absence of independent safety testing, and advise a moratorium on their use until studies can demonstrate their safety.
Companies use nanoparticles for different reasons. Many are using them as delivery systems in anti-aging creams, arguing that nanoparticles will drive other anti-aging ingredients (specifically anti-oxidants) into the dermis where they will promote collagen production and prevent cell damage. FOE points out, and rightly, that if they do indeed drive other ingredients into the skin then the risk of doing damage would correlate to how many harmful ingredients contained in the product are also being carried to the dermis, notably parabens, other preservatives and fragrances. However, as we do not really know whether nanoparticles penetrate intact skin, or whether they act as uptake for other ingredients, it’s at best an academic argument and at worst unduly alarmist. As an anti-aging mechanism nanoparticles show promise, but we are a long way from knowing whether they are creating more damage than they are delivering benefits.
Many companies are adding micronized mineral particles to their sunscreens, and FOE adds a caveat about this practice: “Nanoparticles of titanium dioxide and zinc oxide-used in large numbers of cosmetics, sunscreens and personal care products-have been shown to be photoactive, producing free radicals and causing DNA damage to skin cells when exposed to UV light.” This is a large claim, and while perhaps sounding a warning klaxon a bit on the side of shrill, it does underline the crying need for more testing of this new technology.
UVA Protection-We know we need it, but do we know to get it?
Aside from the question of whether nanoparticles generate free radicals, there is another problem associated with micronized sun protection products that we can state unequivocally: the smaller the particle, the less effective the UVA protection. This is because mineral sunblocks work differently than chemical sunscreens, which absorb UV rays, lowering energy levels and releasing energy as heat. Mineral sunblocks reflect or scatter energy rays, and for this reason are non-irritating, unlike chemical sunscreens which may cause skin irritations and even rashes, especially at higher concentrations. Micronized minerals are not as efficient at the physical process of scattering rays, so the question arises–we may have a product that disappears on the skin that people will wear, but how much protection are they actually getting?
The temporary answer, at least until such time as we know more about the effects of nanoparticles, lies in using a product that contains a high concentration of non-micronized zinc oxide. FOE lists companies that do not use nanoparticles in their sunscreens/blocks, and there are other small companies not listed that also do not use nanoparticles. Marie-Veronique Skin Therapy is one of them–though FOE did not list our company as one of the “good ones”, rest assured that we are waiting for more information about nanoparticle safety before we use them. There are also several good diaper rash creams on the market that contain high concentrations of zinc oxide in all-natural formulas. You may mix them with your daily sunscreen to ensure that you are getting adequate protection.
Sunscreens and skin cancer
On another note. A new sunblock has come out on the market that is a micronized zinc oxide at 16% concentration. It claims that it gives UVC protection. UVC are the very short wave-lengths of light that do not enter the atmosphere as they are blocked by the ozone layer. Clearly in areas where the ozone layer is thin or absent (like Australia) UVC is a problem. It is said that everybody over 40 in Australia has skin cancer (usually of the basal cell carcinoma type, where lesions are slow-growing and require removal by a physician, but are not life-threatening). However UVC exposure is a potential and very real hazard. No sunscreen or sunblock protects against UVC rays—so if you live in a high-risk area you should limit your sun exposure and wear clothing and hats. As much as I admire zinc oxide for its great benefits I know it doesn’t protect against UVC rays. Beware sunblocks or sunscreens that claim they offer UVC protection—it’s not true, and it is extremely irresponsible, bordering on criminal in my opinion, for companies to be making such a claim.
