Friday, March 07, 2008

Sunscreen Active Ingredients

Sunscreen Active Ingredients
In preparation for a lot of sunscreen reviews, here's a bit of information about the acitve ingredients in sunscreen. While not the most exciting post (been stuck at work, this is the only post I have completed right now.... Sorry... expect me to spend all day Saturday writing!), I'll be referring to this post frequently in the near future!


There are two main types of Active Ingredients, which you should familiarize yourself with before you buy your next sunscreen.

Chemical
Chemical sunscreens absorb the UV rays, preventing them from reaching your skin.
examples: PABA (paraminobenzoic acid), oxybenzone, cinnamates, and butyl methoxydibenzoyl methane.

Physical
These ingredients actually reflect the UV rays off of the skin.
examples: zinc oxide and titanium dioxide.

In addition to considering the type of sunscreen, you need to consider what UV Spectrum you will be covering. You want broad-spectrum UVA and UVB coverage, which generally will take at least 2, usually 3 active ingredients. Look on the back of the sunscreen, legally they need to be listed there.

Short Wave UVA
• Benzophenones
- Oxybenzone
- Sulisobenzone
• Dioxybenzone
• Ecamsule (Mexoryl)

Long Wave UVA
• Avobenzone (Parsol 1789)
• Ecamsule (Mexoryl)

UVB
• p-Aminobenzoic acid (PABA)
- Padimate O: FDA approved as a photo-protectant, this ingredient has quite a bit of debate about it. There is some evidence that when it is activated by the sun it actually directly causes DNA damage to cells, making sun damage worse, it also protects somewhat into the short wave UVA spectrum.
• Salicylates
- Homosalate
- Octyl salicylate = Octisalate
- Trolamine salicylate
• Cinoxate
• Octylmethoxycinnamate = Octinoxate
• Octocrylene
• Ensulizole: This also protects into the short range UVA range

Broad Spectrum UVA and UVB
• Titanium dioxide
• Zinc oxide

Sunscreen Active Ingredients UV Coverage Range
Update, 4/10/08
See this cool new chart? It will show you more visually which parts of the UV spectrum each sunscreen covers! I spent a lot of time figuring this out, but really, those are all of the FDA approved sunscreen active ingredients, I'll be customizing this graphic for each sunscreen review!

The Skin Cancer Foundation's Seal of Recommendation
While I'll be reviewing quite a few sunscreens soon (and referring to this post often), I doubt that you'll bring a list of ingredients with you to Target. (I do hope you'll read the reviews and do a bit a research before you buy your next tube of sunscreen.) But, one of the easiest thing to do is to look for the Seal. The Seal has some requirements, companies seek it out and they can't buy it.

• A sun protection factor (SPF) of 15 or greater (note that they don't require broad spectrum UVA and UVB coverage, you'll need to check that out on your own)
• Validation of the SPF number by testing on 20 people
• Acceptable test results for phototoxic reactions and contact irritation
• Substantiation for any claims that a sunscreen is water- or sweat-resistant

You can view a list of all the products that have this Seal at The Skin Cancer Foundation's Site

5 comments:

Sharon said...

Hey,
Great idea to check the seal when selecting a sunscreen!
Should we buy a moisturizer with an high SPF value for both day and night use?
Let me know.
Cheers,
Sharon

Christine said...

I think that you need to tailor your SPF for your activity that day. I personally think of my sunscreen in 3 different levels of coverage.

For everyday, just running errands, going to work, etc you need SPF 15. That can be in either a lotion or sunscreen, but you likely don't use enough foundation for that product to count. Broad spectrum coverage is desirable for this, but if you're just running to and from the car for a few minutes it is probably not as important.

For me, if I'm spending some more time outside, for example I'm going to Disneyland with my nieces or I'm outside for a few hours at a restaurant or something, then I try to use something with a broad spectrum UV coverage and at least SPF 30, 45 is even better. For these days I want something that I do not notice on my skin at all, though a bit of a smell is pretty much unavoidable. I just don't want to feel sticky. I don't care about waterproof for these days.

Finally, I go for super coverage when I'm really in the sun all day, for example at the beach or pool for the day. In theory you really aren't adding a lot of coverage by going from SPF 45 to SPF 70, but that little bit can be a big deal for a pale irish girl like me! When I'm at the pool I'm going to be a bit sweaty anyways so a bit of stickiness is ok, and I definitely want a waterproof formula. Why? Because even though I'm a good girl and I reapply as soon as I'm out of the water, I do want some of that coverage to still be there while I'm in the pool!

I hope that helps!

Dee Vazquez said...

I am an organic skin care manufacturer and I wish we could find a natural sunscreen product that is all natural, non-greasy and actually guaranteed effective.

After trying almost everything, we believe no-one has done it yet! We simply cannot find a single sunscreen that isn't either greasy, has that terrible white finish or is full of questionable chemicals and perfumes.

If the active ingredients are natural mineral based (reflect rays) they need to remain on the surface of the skin to be effective, so the product is almost always greasy. If the active ingredients are chemical based (absorb rays) then the product may soak in nicely but the chemical ingredients are questionable in terms of their long term effects on health and irritation potential!

I have fair skin and I run a biodynamically grown herb farm, so I can't keep out of the sun for long. I NEED sunscreen, but I hate the stuff!

Thanks so much for your blog - I am going to keep an eye on your reviews to see if you can't find the solution!

Martha said...

I'm confused: you list titanium dioxide as broad spectrum, but in the chart, it seems that this only filters UVA. Can you clarify?

Christine said...

The chart is NOT organized by what is covered, again, it is just all spread out so you can see all of the chemical names. Titanium Dioxide is generally considered to be "broad spectrum" and is listed as such by the FDA. However, it covers UVB and UVAII only, not UVAI

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