Choosing a sunscreen: SPF and "hazardous" chemicals?

March 20, 2011 10:44 AM

Two questions about choosing an everyday SPF face moisturizer: 1) What SPF do I really need? 2) How much credence to give the Environmental Working Group's sunscreen ratings?

I'm in my late 20s and I have very pale, freckly, dry skin -- so I make it a priority to put an SPF moisturizer on my face every morning. For the past couple of years I've been using Neutrogena Healthy Defense SPF 45. I like that it has a relatively high SPF and it doesn't make my skin go crazy (most products do). My current bottle is running low and I'm considering switching to something else, possibly tinted (my face has been breaking out much more frequently lately and I'd love to have an all-in-one product that would even out my skin tone a little bit). The current frontrunner is Boots No. 7 Soft and Sheer SPF 15, but I'm concerned about the drop in SPF.

On a normal day I'll spend between 20 minutes and an hour walking outside (if I know I'm going to be spending substantially more time outside than that, I'll usually put on a more heavy-duty (SPF 60+) sunscreen). On top of the time fully exposed to the sun, I spend maybe 40 minutes a day driving, and a negligible amount of time sitting near windows at home and at work. What SPF do I actually need in a daily moisturizer? At what point are there diminishing returns? Is it significantly worse for my skin to use SPF 15 instead of SPF 45? There are so many conflicting opinions out there and much of it is framed as dramatically as possible that I have no idea how to figure this out.

I'm also not sure how worried I should be about the "potentially hazardous" chemicals that the Environmental Working Group seems to say are in all but the most expensive sunscreens. I definitely can't afford to spend $40 on a moisturizer, but I don't know how much credence to put into the claims that some sunscreens do more damage to your skin than the UV rays they protect you from. The EWG rates my current moisturizer as a 7, which falls within the "avoid" range. Should I actually be avoiding the chemicals that the EWG is vilifying?

I'd love some links to meta-analyses of sunscreen effectiveness, or at least science-based analysis that isn't grounded in fear-mongering. The Metafilter community is often good at cutting through all the pseudo-scientific hand-wringing and dealing with these types of things pragmatically.

posted by enlarged to show texture to health & fitness (10 answers total)

Try the Boots that you want to try. I'm relatively pale and find that for workdays, where I get about the same amount of exposure that you do, an SPF 15 works well. You can always layer on more for the days when you will get more sun, which I also do.

I haven't read the EWG report, but there are potentially hazardous chemicals in your life every day, so you can only weight the risks and needs. I agree with them that personal care products are sometimes a significant source of risk, but a decent, not-too-expensive sunscreen is a risk I'm willing to take to counter the known risks from too much sun. Maybe this is polyanna-ish of me, but I think of it as my only buying one bottle of the product, not signing up for a lifetime of exposure. As we know more about the risks from chemicals, companies can change formulations. Which is why I advocate just trying the product that sounds good to you.
posted by ldthomps at 11:07 AM on March 20, 2011

Thanks for this question. I have been meaning to re-listen to Dermatologist Offers Tips For Skin, Sun Safety, which appearned on NPR's "Fresh Air" a couple of years ago. IIRC, the doctor who is interviewed breaks down exactly what SPF numbers really mean.
posted by MonkeyToes at 11:16 AM on March 20, 2011 [1 favorite]

Here is a description of how you can calculate the SPF that you need.
posted by neushoorn at 11:27 AM on March 20, 2011 [6 favorites]

I'm fair and use an SPF 15 moisturizer each day, whether it's a day I'd wear make-up or not.

One thing to consider: if you use a tinted sunscreen that's also a cover-up, you might not use as much as you'd use of your (probably less expensive) stand-alone SPF. And I slather it on my face and neck. Will you use as much if it's for coverage as much as sun protection?

I hope this isn't a derail--just similar things I've been thinking about.

Another reason you might be breaking out: I noticed as I hit my later 20s that my skin started to change and some break-outs were actually because my skin was dry and I wasn't using enough moisturizer. So maybe your skin is changing?
posted by bluedaisy at 11:48 AM on March 20, 2011

SPF measures only a sunscreen's protection against UVB (burning) rays, not UVA (aging and cancer-causing) rays. It's important to choose a sunscreen with good UVA protection; this one, with a UVA-blocking ingredient that became available in the US only recently but has been around in Europe and Canada for a while, is my favorite. EWG seems to like it too. It is expensive, though.
posted by Ralston McTodd at 12:45 PM on March 20, 2011

Does the breaking out coincide with the usage of the sunscreen? (Or that particular brand?)
posted by gjc at 1:00 PM on March 20, 2011

Where you live also matters. When I moved to Nevada and lived in the desert, I did not up the SPF that had worked just fine for me in California, and got serious sun damage on my face.
Now, I always suggest that people err on the side of higher SPF because it's hard to get sun spots to go away once they're there.
posted by smoakes at 1:24 PM on March 20, 2011

I don't always understand the different, but some sunscreens are stable and some, unstable and it's important to pick the latter. I prefer physical sunscreen, for its broad-spectrum protection and the fact that I don't need to worry about reapplying as much: burnout clean & clear is awesome.

I'm a broken record when it comes to this, but makeup alley's skin board is super knowledgeable.
posted by R a c h e l at 1:31 PM on March 20, 2011

I was in the same boat last year, did a ton of research, and ended up going with 100% Pure SPF 15 sunscreen for face and Badger or Soleo for body. They're all physical blockers (titanium dioxide), which are photostable and also apparently less hazardous for your body than the chemical sunscreens. EWG loves Badger and Soleo, and 100% Pure isn't in their database, but the ingredients look ok. The trick with EWG is that they rate all fragrance as "extremely hazardous" because some fragrances contain phthalates. There's also a big data gap, meaning some ingredients and their interactions just haven't been adequately studied.

I can tell you that on a trip to Puerto Rico, my friends with drugstore SPF 45 sunscreen got burned, and I was fine with my Badger SPF 15.
posted by enzymatic at 5:10 PM on March 20, 2011 [2 favorites]

Disclaimer: I write about sunscreens and moisturizers for a dermatological audience, and some of my clients are mentioned above. I also have fair skin and freckles, and must use a daily sunscreen or I burn like a cheap halloween costume.
Physical sunscreens contain mineral-based sunscreen ingredients -- usually zinc oxide and/or titanium dioxide (TiO) -- and are generally considered non-irritating. It's hard to get a physical sunscreen to be both transparent AND high-SPF like you want in a moisturizer. Most high-SPF (over 30) moisturizers use chemical ingredients that don't break down under long-term UV exposure, like your Healthy Defense. If you are worried about these chemicals (as the EWG seems to be) you could try a version of your favorite brands that have "micronized" TiO. (By grinding up the mineral finely, it seems to enhance its UV blocking abilities.)
Finally, while SPF only measures UVB rays, any sunscreen labeled "broad-spectrum" or "full-spectrum" will offer provide both UVB and UVA protection. To be safe, it's not a bad idea to reapply your moisturizer halfway through the day.
posted by memewit at 7:47 PM on March 20, 2011 [1 favorite]