Saturday, September 24, 2011

Zinc Oxide vs Titanium Dioxide {Sunscreen}

[Source:holistickid.com]
So, we talked about physical and chemical sunscreens in this post. I explained that I do not prefer chemical sunscreens because they produce free radicals in the body. So, now, we come down to physical sunscreens. Now, there are only two ingredients which has the properties of being physical sunscreens - Zinc Oxide and Titanium Dioxide.

Now, do you remember my post on the sunscreen breakout problem?? It was posted quite long back. In that post, I had simply stated that a sunscreen with Zinc Oxide will solve the breakout problems. Why did I not state anything regarding Titanium Dioxide? Let's see if I can explain it.

Zinc Oxide
It is the best broad-spectrum UV filter known till now. And, it doesn't cause any allergic reactions on the skin too. In fact, Zinc Oxide is pretty good for acne skin because of its anti-bacterial property. It just sits and disperses the light falling on the skin without allowing it to get to the skin surface. It doesn't get absorbed by the skin. But, there are certain downsides to this ingredient. 

Zinc Oxide is notorious for leaving a white cast on the skin. The Zinc Oxide sunscreens are thick and a little powdery in texture which might leave a powdery cast on the skin. These sunscreens do not blend on the skin very easily too. It takes a little getting used to the texture of the product. 

Titanium Dioxide
So, you might have heard the debate whether Titanium Dioxide is poisonous or harmful to the skin or not. Ok, so let me first say, this is the second best ingredients for sunscreen but it doesn't give a broad-spectrum protection. It lacks UVA spectrum protection. And, it is also known to be allergic to the sensitive skin. Well, Titanium Dioxide is one of regularly used ingredients in mineral makeup and if mineral makeup breaks you out, Titanium Dioxide allergy might be one of the factors. Even Titanium Dioxide leaves a white cast like Zinc Oxide.

So, let us first say how this ingredient protects from sun's rays. It uses both absorption and dispersion methods. So, yup, you might ask me if it doesn't produce free radicals? Well, I have been trying to hunt down for that answer and this is what I found: http://personalcaretruth.com/2011/01/does-titanium-dioxide-cause-free-radical-damage. Well, check out the article for detailed explanation. 

Does Titanium Dioxide produce free radicals?
Well, there are two types of Titanium Dioxide which can be used in the products - Rutile and Anatase. These are the polymorphs of original Titanium Dioxide and thus, differ in certain properties. So, as it comes out, rutile is less photoreactive than anatase form because it has highest refractive index of all the known minerals and it also has high dispersion properties which means that rutile Titanium Dioxide reflects the UV light more than absorbing it. 

Now, you need to be concerned about which form is present in your product. So, the answer given is that generally it is the rutile form which is more commonly used but in case of doubt, the manufacturer of the product should be contacted. Not a very good answer but the summary is that you need not be bothered about the absorption because it is very less likely to damage the skin.

What would I choose?
Well, my answer would be Zinc Oxide as it is broad-spectrum and more effective but I definitely wouldn't mind Titanium Dioxide in mineral makeup. That would add some sun protection to the makeup you are using.

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