Sunscreen 201

Yeah it’s sunscreen 201 not 101 because I’m givin’ you to some higher sunscreen knowledge.

First let’s talk about the types of damage our skin faces from the sun. They say that sun damage is the #1 cause of age on the skin. Even ahead of free-radical (pollution) damage. UV rays are the culprits for this, there are 3 different types of UV rays:

UV(A)ging

UV(B)urning

UV©rispy [I made that one up but you’ll see why]

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(credit: coola.com) (they make some bomb sunscreens too btw)

As we can see UVA rays penetrate the deepest, because of this these rays are the ones responsible for what is known as photo-damage. Photo-damage can come in the form of: dark spots, uneven skin tone, dehydrated skin; and worst of all, accelerated aging. These are actually the most prominent rays making up 95% of radiation from the sun that penetrates the OZone layer. These are also emitted from traditional indoor lighting sources too. (Yeah your lamp might be aging you I’m not even shitting you) LED lighting is said to produce no harmful amount of these rays. (HOWEVER ENOUGH TO ATTRACT MOTHS TO THE LIGHT STILL THANKS GUYS)

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(This is Bill McElligot, a truck driver for over 30 yrs showing increased UVA damage, car windows block 100% UVB rays but don’t do much when it comes to the sleeper UV rays)

UVB rays don’t always reach the epidermis, and frankly we don’t want them reaching us at all. UVB rays are responsible for sunburns, pink arms, and all the unpleasant sensations that come along with “too much sun”

Then we have UVC rays, which I will explain even though it’s irrelevant to most of the world. These are the strongest, most intense rays from the sun, and they actually cannot penetrate the OZone layer. However, since we’ve caused a couple holes in the southern hemisphere there are areas which you can be exposed to these rays. But hypothetically speaking, any prolonged exposure to UVC rays will cause much more damage than the other two. 

Now we know what sun damage is and what causes it, lets talk about SPF. Spf stand for Sun Protection Factor and this is the measuring system used to tell us how well the sunscreen can protect against UVB rays. Specifically speaking, SPF will tell you how much longer before you would start to burn. SPF 20 is 20 times longer. 35 is 35 times longer. But this is frankly a useless way to look at SPF in my opinion since reapplication, formula, percentage, quality, etc are all factors. SPF can range from 10 all the way to ‘50+’. SPF is also not a linear rating system so SPF 20 isn’t double the protection of SPF 10. Here’s a chart of protection: 

SPF 0: 0%     SPF 10: 90%

SPF 15: 93% SPF 30: 97%

SPF 50+: 99%

No there’s nothing higher than SPF 50 no matter what neutrogena tries to tell you! There’s no 100% protection from the sun unless you’re just not being exposed to it. Most brands now, and any brand with integrity simply state ‘SPF 50+’ as an indicator there may be a temporary effect of a ‘higher spf’. Everyday use is recommend of course but a minimum of 15 should be worn everyday, while an SPF 30-50 is more suitable for going to the beach, etc. Some sunscreens can have a less pleasant texture when delivering more protection.

Now there’s also another rating system we see sometimes on sunscreens called PA. This stands for “Protection of uvA” The PA rating can This is actually a conversion from how the rest of the world rates sunscreen for UVA (remember aging!) Ratings range from PA+ to PA++++ of course the more pluses the more protection. 

Sunscreens that protect against both UVA and UVB are called ‘broad spectrum’. I’m sure you’ve heard this phrase at least once in your life.

Now that you know the Sun is the devil, we’ll move on to the different types of sunscreen. Physical vs. Chemical.

 Physical sunscreens are minerals that block and reflect harmful UV rays. Titanium dioxide and zinc oxide are currently The only two physical sunscreens. Both happen to be broad-spectrum sunscreens, meaning they protect against both UVA and UVB rays. Because of how these sunscreens work they can often times leave a sick and uncomfortable feelings.Physical sunscreens interact less with the skin compared to chemical sunscreens, making them more ideal for sensitive skin. These minerals are naturally white, therefore they can meet a white cast for streaking if not tinted. Considered to be the safest sunscreen option by most however there’s a lot of controversy over their saftey and the possibility of nano sized particles of these known carcinogens absorbing through our skin into our blood stream. I’m not frankly worried about it and don’t think you should be either. But hey, that’s just me. 

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Drunk Elephant Umbra Defense (Left) VS Tony Moly Mild Mango Block (Right)

The drunk elephant sunscreen is 20% zinc oxide, no fragrance so it smells like… mineral sunscreen.. or aka pennies. But this is to show the ‘white cast’ effect. Which in this physical sunscreen it’s minimized since there’s color correcting pigment added.

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Chemical sunscreens are also known as organic sunscreens. Reason being they are generally derived from carbon. Chemical sunscreens generally work by causing a chemical reaction that converts the harmful UV rays into heat which then leaves our skin. These can cause irritation to some sensitive skin. Benefit over physical sunscreens is the increased UVA protection.These do take up to 20 minutes to activate. Some chemical filters can generate free radicals so we see many of them packed with an antioxidant boost to cancel out that effect. Some filters like avobenzone are very unstable, however it is one of the filters that protects against both UVA and UVB rays. Filter sunscreens have a tendency to be light weight compared to physical sunscreens, they also do not produce a white cast making them in a great choice for any skin tone.

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(credit: futurederm.com)

While there are a slew of different chemical sunscreens and they all have their own pros and cons. Many sunscreens actually aren’t sold in the US but can be purchased overseas in countries more conscious about their skin darkening. The US FDA is very slow at approving things (but also very slow and banning things it doesn’t make sense)

 I hope this helps you navigate your next sunscreen purchase!

美容护肤

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