Does Titanium Dioxide Cause Free Radical Damage?
The UV Factor
In a followup to my article on Titanium Dioxide and the EPA report on the safety of TiO2, another question has been a concern for some in terms of titanium dioxide causing free radical damage to skin or aging the skin when exposed to UV light.
So in order to elaborate in depth and to address this valid concern, I felt it was prudent to explain the differences and to show again, the theory and science that has shown Titanium Dioxides’ fantastic properties to not only refract UV Rays, but will also absorb them……but what does this mean for the skin? It’s benefits also supersedes other synthetic sun filters, and is still the most popular mineral sun blocker next to zinc oxide among sun protection ingredients. Based on this fact of UV absorption with certain sunscreens and sun blockers, the distinction must also be made of the varying types of TiO2, so consumers don’t avoid this ingredient based on half of the science or a possible misconception of the actual research.
Many blogs or articles equate the problem with photocatalytic response (free radical damage) to nano size versus the supposedly safer standard micron size Titanium Dioxide…..or they feel it is any version of TiO2, when this is actually not the case and the facts are slightly skewed.
A distinction needs to be made, and the fact is, anatase nano-TiO2 is more photocatalytic than the rutile form, and nanoscale rutile is less photoreactive than either anatase and rutile mixtures or anatase alone.
So the hypothesized research sometimes is incomplete or is not vetted to the point of clarification on some of these broad terms within these very basic articles. Thankfully the EPA report has made the distinctions, including creating a better understanding of the exposure factors as related to rutile versus anatase and then their relation in terms of nano particles. Plus factors of delivery system within different products is key to determining effects on the skin.
EPA Report Clarifies
According to the EPA Report Nano-TiO2 formulations of sunscreen have proven popular because they appear transparent on the skin; formulations using conventional TiO2 or other inorganics such as zinc oxide (ZnO) create a milky white appearance. Nano-TiO2 serves as a sunscreen in two ways, by absorption and scattering, depending on the wavelength of UV light. UV-B wavelengths are in the range of 290 to 320 nm, and are primarily absorbed by nano-TiO2; UV-A wavelengths are in the range of 320 to 400 nm, and are primarily scattered by nano-TiO2. Optimal scattering is thought to occur when the diameter of the particles is approximately half the wavelength of the light to be scattered.
Conventional TiO2 absorbs and scatters UV radiation, making it an effective active ingredient in sunscreens. Like ZnO, TiO2 is a “physical blocker” of UV radiation, as opposed to many chemically active ingredients that serve as “chemical filters,” such as avobenzone and benzophenone, which in some individuals can cause adverse skin reactions, including blisters, itching, and rash. Thus, sunscreens containing physical blockers have long been an attractive option to those with sensitive skin.
Apart from this niche market, the use of TiO2 in sunscreen was historically limited because of aesthetic considerations. Because conventional TiO2 scatters visible light, it remains visible as a white film when applied on skin. With the advance of technology to produce transparent nanoscale TiO2 particles, which scatter very little visible light and therefore appear transparent when applied on skin, nano-TiO2 has entered the mainstream as an active ingredient in sunscreens and has also been added to numerous other cosmetic products to provide UV protection. With exposure to UV radiation (wavelengths less than ~400 nm), pure anatase nano-TiO2 is photocatalytic. In sunscreen, however, photocatalysis is an undesirable property that can be addressed by applying surface treatments to the crystals, selecting a less photoreactive form (rutile), or adding antioxidant ingredients to the formula.
Similarly, surface coatings of silicone and other compounds are used to decrease nano-TiO2 photoreactivity so that nano-TiO2 can be used to protect human skin from UV radiation.
Europe, Australia, Canada, and South Korea also have approved the use of TiO2 as a UV filter in sunscreen with a maximum concentration of 25%. Japan does not regulate TiO2 as a UV filter in sunscreen.
Knowing Which Is Which
Unfortunately, product labels do not distinguish between Rutile and Anatase, forms of Titanium Dioxide, (wikipedia) or whether or not they are coated or uncoated. However, there is one determining factor which can help to ease ones mind in this regard…..
Rutile is the most common and popular version readily available on the market and it has among the highest refractive indices of any known mineral and also exhibits high UV dispersion. It is also the most stable form……so odds are in your favor, this is what you are using on your skin when applying sunscreen containing TiO2. When in doubt, you may try to contact the manufacturer and inquire as to the type of Titanium Dioxide they are using.
Skincare Can Help
In terms of using mineral powders versus liquid sunscreens or liquid foundations, powders sit on top of the skin, while liquids are absorbed into the surface layers. So as to my interpretation of the presented data, mineral powders appear to be less problematic in regard to any concern of aging the skin. However, to take it a step further, as was determined in the EPA report, the addition of surface treatments and antioxidants to the formula, have shown to work further at the skin level to fight free radical damage caused by the minimal oxidation process which occurs when UV light is absorbed by these excellent sun blockers applied to healthy skin.
This is another reason we endorse always using a good moisturizer rich in antioxidants, prior to applying mineral makeup. The fact of the matter is, powders simply do sit atop the skin giving sun protection, whereas a moisturizer is the catalyst for dispersion and absorption of the antioxidants into the surface layer of the skin. This protects the skin from further damage and fights accelerated aging caused by the sun and airborne pollutants we are exposed to daily.
The best antioxidants found in skincare or as a constituent of another ingredient, are Vitamin A, Vitamin C and Vitamin E. Jojoba oil is perfect for this, and just another reason it is included in our mineral makeup. It has antioxidant constituents of Vitamin C and E and is highly stable, even under extreme heat…..it will also not go rancid since it is not a vegetable oil but a wax ester, and in fact is used as a carrier oil to stabilize other more volatile oils.
Keep Skin Healthy
Based on the evidence and the fact that sunscreens have the highest popularity of use when they include Titanium Dioxide and / or Zinc Oxide in their active ingredients, also found in natural products, this should further support the ideal of these two ingredients being the safest method of keeping the skin protected from the suns’ UVA and UVB Rays……which is also key since these “sun blocker” ingredients when utilized in combination, create the ultimate in broad spectrum sun protection.
It is also important to note that the sun will cause far more radical damage on exposed skin than it will with the use of TiO2. Another example of the benefits far outweighing a concern for use, especially since it is subject to the type of titanium dioxide used and with the incorporation of surface treatments or antioxidants.
Skin Deep Database Stirs Confusion Daily
When I wrote my article on the Safety Of Titanium Dioxide in Mineral Makeup back in Nov. 2008, the Campaign for Safe Cosmetics and EWG had this ingredient rated at a 5-8. Just out of curiosity, I returned to it today and yet again, this ingredient has been reduced back to a 1-3 in low hazard with 83% data gap.
I can’t help but wonder, what epiphany the members had to reduce the score? All the info is the same, data gap is the same…..makes one think! Plus I now also noted that they have a clickable emblem under ingredients used in sun care products, taking you to their recommendations for sunscreens, along with their online store……which I might add is another way they are generating income to support their agenda in order to continue to provide the unscientific, incomplete data to the masses. All of their top picks have a common thread, however, Zinc Oxide and Titanium Dioxide are used in combination within the formulas.
But wait….they also provide a category for chemically laden sunscreens, or as they so aptly name this selection, Non Mineral Sunscreens with the following statement below:
“None of these non-mineral sunscreens earn our top rating. But here are some choices for people who prefer to avoid nano-scale minerals (zinc and titanium) or who object to the feel or smell of mineral sunscreens. The trade-off? All non-mineral products contain at least one sunscreen chemical considered to be a potential hormone disruptor, and many offer only moderate or weak UVA protection.”
Based on the evidence presented, why would anyone need to avoid nano scale, since it is now shown to be the least photocatalytic, is the most photo-stable, and clearly does not penetrate into human living cells as was once believed?
But opposingly with their list of Top Sunscreens they make this statement below:
“Our top-rated sunscreens all contain the minerals zinc or titanium. They are the right choice for people who are looking for the best UVA protection without any sunscreen chemical considered to be a potential hormone disruptor. None of the products contain oxybenzone or vitamin A and none are sprayed or powdered.”
Confused? My eyes just rolled back into my head…..broad statements without science or explanation creates the uncertainty experienced by so many today. And Vitamin A is a well known anti aging ingredient and has been used for decades, and is found in many skincare preparations including concentrated preparations provided by dermatologists…..okay that’s another story for another time….but the EPA made no distinction with Vitamin A, and used the term “antioxidants” for further protection of skin. Plus, I saw all the hype last year brought on by EWG, and it was so over the top, I chose to ignore the claim since the theories and suppositions surrounding the contrived controversy, were without merit and baseless and there were no peer reviewed studies done. Besides, there were plenty of others, far more qualified than myself, prepared to refute this ridiculous claim.
So for those that are curious about Vitamin A in relation to sun exposure, I’ll leave the findings to the scientists. The links I offer will help you gain a ton of knowledge offered by the Skin Cancer Foundation or Science Based Medicine which is dedicated to Science based evidence written by those in the medical field. Chief Scientist John Bailey with the Personal Care Products Council gives a full statement in regard to the accusations leveled against certain sunscreens, including the use of Vitamin A.
However it seems, zinc or titanium are clearly the better choice in order to avoid those other nasty sunscreen chemicals, but the EWG offers the chemical versions for sale if you are more afraid of nano particles in the mineral options…..huh? (scratches head)
Either way, with all their theories, it appears to smack of hypocrisy to me since we are witnessing a commercial vested interest through the sale of multiple types of sunscreen, including the chemically laden ones they dislike so much. And if the skin deep database and EWG are suppose to be the “go to” road map to sound decision making, then this would be like reading a road sign without distinct direction with all of their disclaimers and contradictions, including their “if’s and’s or but’s”…..but, I’ll leave this one for the masses to decide, ’cause this gal is going with the science every time.
Related Article: Titanium Dioxide in Mineral Makeup, Final Report By EPA
More about the author: Katherine Corkill is the founder and creative director of Sterling Minerals Cosmetics. She became inspired to create products that would assist men and women in restoring the radiant healthy skin of their youth. Read more from this author