Tuesday, January 29, 2008

Sun Protection!

This may sound funny, but I really had to gather all my energy for just this one post, so here we go. This is a totally watered down version as I'm not going to go into too much details. However, I do have links for you to read on, and you can always explore for yourself too - try Google :D In all honesty, I'm no sunscreen expert and all I know is from what I've read thus far. So if I've posted incorrect or misinformed information, please do educate me. I'm always very interested in the subject of sun protection.

The Basics
You should wear some sort of sun protection with a minimum of SPF 15. If you love the outdoors or are on higher elevation where the UV index is stronger (because among other reasons, there's obviously less atmosphere to filter it for you!), I strongly recommend a minimum of SPF 30. Some people would even say you must wear sun protection daily. No, I'm not paranoid, nor am I a vampire/zombie/creature of the dark who's somehow afraid of the sun. Wearing sunscreen is just a healthy practice, that's all, like avoiding trans fat and regular exercise.

The Next Step
Your sunscreen/sunblock has SPF 30, so you're all set, right? Well, that's what its maker wants you to think. The truth is, in order to get the labeled SPF you'll need about 1/4 teaspoon of the stuff for your face and another for your neck, more or less depending on the surface area of your face and neck. Why? Because that's the amount used during testing to come up with the labeled SPF, but of course you're not going to find that printed on the label. Sneaky? No doubt. Is it true? Absolutely. Don't believe me? Read it for yourself from the US National Library of Medicine and National Institutes of Health.

That's a lot of goo, huh? What, there's no way you'll goop that much on your face and then your neck? Well then, you'll get 1/3 to 1/10 of the labeled SPF, depending on how little of an amount you use. So let's do the math, 1/3 of SPF 30 is 10, and 1/10 is 3 - GASP!!! Hello sunburn, sun spots (no, not those sun spots on the Sun!), discoloration, premature aging, wrinkles, or worst yet, skin cancer! The moral of the story is - the higher the SPF, the better (sort of), so don't cut corners with the bare minimum.

The Next Level
So now you're up to SPF 70, and all is peachy, correct? Not exactly. In short, UV rays comprise of UVA and UVB rays. UVA causes tanning and photoaging (premature aging, skin damages, breaking down collagen in the skin faster than if a person were to age naturally, etc.), and UVB causes tanning and burning. UVA protection is loosely described by a PPD rating, and UVB protection is quantified in the SPF rating. Now, in all the sunscreens/sunblocks you've seen in the US, have you seen any labels showing a PPD rating? No? That's right, because sunscreen/sunblock makers in the in US do not quantify their PPD ratings. Why? No idea.

So all this time, you've only been protected against UVB and not UVA? Yes, and no, because supposedly, the higher the SPF, the higher the PPD. For example, Neutrogena Ultra-Sheer Dry Touch SPF 70 has a PPD 11-19 (different sources list different numbers), Shiseido Ultimate Sun Protection SPF 55 PA+++ has a PPD 8-10, while most other US SPF 30+ sunscreens/sunblocks has a PPD of 4-6. Ever wonder why US sunscreens/sunblocks have such low PPD protection? Because the FDA have yet to approve the key ingredients that have been proven to provide effective UVA protection (except for Meroxyl, which the FDA finally approved in just 2006, 13 years after it has been widely available in Europe!). The Skin Deep article below shows how far behind the US is in terms of safe and effective sun protection with regards to the EU, Australia, and Japan. Pathetic? Yep.

The point is - stick to the strongest sunscreen/sunblock you can tolerate (or afford...). A PPD 8-10 is okay for daily use, when you run errands, get groceries, etc. But if you're going for a run, hike, the beach, or otherwise being under intense sun for more than half an hour, a PPD 8-10 won't do. Some people would even say adequate UVA protection starts at PPD 15+. Try European sunscreens! The majority of of them have a minimum PPD 15!

The Extra Mile
Alright, so why the hell do I bother to distinguish between sunscreens and sunblocks. That's because there's actually a difference! A sunblock provides "physical" protection, forming a physical barrier on top of the skin while a sunscreen provides "chemical" protection, penetrating the top dermis layers and forming a chemical layer. There have been concerns whether the active ingredients in chemical sunscreens have particles small enough on nano scale to be absorbed into the blood streams and becomes toxic to the body (see the Skin Deep article below for more details).

And then there's issue of photostability. Rolling your eyes yet? Don't blame you. What the hell does that mean, right? Well, if you would believe it, depending on formulations, most sunblocks/sunscreens actually breaks down in the sun. Yes, that means their chemical infrastructures collapse and become useless. So when you buy sunscreens, look for one that are photostable. See the 2 Makeup Alley links for a list of photostable sunblocks/sunscreen and how to tell from a product's ingredients whether it is photostable (Warning: it can get technical!).

Next, we have the issue of substantivity. Foaming at the mouth yet? Hang in there. Anyway, most sunblocks/sunscreen don't stay put on your skin, even with the labels claiming water and sweat proof. As far as I'm concerned, the only way to tell how well it sticks is to try it on. If the stuff comes off with a wipe of a tissue (when you sneeze, blow your nose, or simply wiping your mouth during lunch), it has low to zero substantivity. Personally, I recommend the sunblocks/sunscreens that need to be removed with a cleansing oil, simply because they won't budge at all with your average face wash. Now that's substantivity! Woo wee!

Finally, we arrive at the issue of cosmetic elegance. Now, now, stay with me here. We're almost there. Ever try a sunblock/sunscreen on and then taking a double take, thinking you're wearing pasty cork grease? Yeah, that's NOT very cosmetically elegant. Again, in my experience, the most cosmetically elegant sunscreens are, again, ones that need to be removed with a cleansing oil. Because they are water and sweat resistant (mind you, the key word here is "resistant," not "proof" - there is a difference!), they are probably mattefying and even a bit on the dry side.

Okay, alright, that's it!!! Hoorah!!! We're done!!!

The Burning Questions
So, you want to know what's out there. Great! Check out the links below and get your feet wet:
- Sunscreen/sunblock FAQ from MakeupAlley
- A list of UVA-protective sunscreens from MakeupAlley
- An article from Skip Deep: Cosmetic Safety Database on the safety and effectiveness of sunscreens/sunblocks

2 comments:

Kelly said...

Just found your blog (through a google search about Cetaphil moisturizing cream) and this post was great! A lot of good info. I had no idea that sunscreens had to be removed with cleansing oil!

Dalenna said...

Hi Kelly,

Thank you for reading. I'm glad you found this post useful.

Not all sunscreens have to be removed with cleansing oil. In my experience, the majority of Japanese-made sunscreens do need a cleansing oil for complete removal because they are VERY water/sweat resistant. American-made sunscreens, on the other hand, do not need a cleansing oil for complete removal and therefore are not as substantive.

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