Summer skin safety: what is SPF anyway?

It’s getting sunny and Harriet and I don’t know how to deal with it. Hyacinth Girl is venturing into the realm of the unknown: in her last post Harriet talked about experimenting with fake tan and now I’m discovering the nightmare that is understanding facial sunscreen. I knew SPF is a thing that I need; that’s about where it stopped until I did a bit of reading. When you start getting into the specifics of what it is and how it works you need to get your science on, and it’s definitely not something you can afford to ignore unless you want to be a) burned and b) cancerous.

I started out by looking at what was in my regular products already. Maybe there would magically be plenty of SPF in my moisturiser and foundation?

At the moment I use Antipodes Rejoice light facial day cream as a moisturiser. Nope, no SPF there. Antipodes do have a ‘face and body’ moisturiser with SPF 15, but that is a) not enough, and b) I’m not sure I’d trust it to be a good face moisturiser if it’s also thick enough to be a good body moisturiser.

Almost everything I know about sunscreen I have learned from Robyn on her excellent blog Brightest Bulb in the Box, which we’ve linked to before. I strongly recommend following her immediately, especially if you like to know the science behind makeup and skincare.

Let’s start with what SPF is. It stands for sun protection factor and relates to the time it takes for your skin to burn when you have sunscreen on. SPF 15 blocks 93% of UVB light, and SPF 30 blocks 97%. That basically means that just because 30 is twice of 15, SPF 30 is not twice as effective as SPF 15 (but it is better). You also want to check your sunscreen is ‘broad spectrum’, that is, that it protects you from both UVA and UVB rays, as they are both harmful.

New Zealand and Australian standards limit SPF labelling beyond 50, as they are misleading. Buying SPF 70 or 100 sunscreen gives you a false sense of security that you’re going to be completely safe from the sun, and so people are less likely to reapply, or stay in the shade, and all the other sensible sunsafe things to do.

The other really important thing to consider is how much sunscreen you’re applying. SPF ratings are measured under the assumption that you’re putting on 2mg per square centimetre of skin. That doesn’t sound like heaps, but IT IS SO MUCH. It’s really, really unlikely that you’re putting that much sunscreen on, especially on your face when you’re planning on putting makeup on over the top. Robyn calculated out how much that translates to for your face and body, and it is a lot. What that means realistically is that your SPF 30 sunscreen is really only giving you the protection of SPF 10 or below.

labeled SPF (at 2 mg/cm2)
SPF at 1.5 mg/cm2
SPF at 1 mg/cm2
15 7.6 3.9
30 12.8 5.5
50 18.8 7.1

Can I combine multiple products with SPF?
You can, kind of. If you’re wearing a SPF 30 moisturiser and an SPF 25 BB cream, it doesn’t mean you’ve now got SPF 55 protection. You can’t add them up. But every layer of product with SPF you’re putting on increases the total amount of product per square centimetre of skin, so it’s taking you closer and closer to a true SPF 25 protection (obviously an SPF 25 product can’t give you that last step towards SPF 30 protection). A good rule to stick to is: the more the better!

But even after all this, the thing that is probably plaguing me the most about finding the right sunscreen for my face is that I want it to be compatible with makeup. I’m totally happy to slather a thick layer of Cancer Society all-purpose sunscreen on my face if I’m at the beach with my family or I’m going swimming or whatever. But for every day I’m still going to be exposed to the sun, and obviously I don’t want to abandon makeup ALL SUMMER.

Oasis Beauty sent me some samples of their different sun protection products for me to try. I really like when brands are willing to send or give free samples! I told them what my skin type and needs were, and they sent me samples of their 3 BB creams as well as a couple of basic sunscreens.

Oasis makes 3 SPF25 BB creams: cream tint (light skin tones, full coverage), honey tint (‘universal’ shade, medium coverage) and caramel tint (darker skin tones, full coverage). Ideally I would go for the medium coverage but unfortunately the honey tint is too dark for me, so I could only try the full coverage, cream tint option. It certainly is full coverage! It gives a very heavy, powder finish which strikes me as a little strange, because as it gets hotter I like to look less like I’ve piled on the makeup and more like I’m just a low key beach babe, no big deal, my skin is always like this, give me a part on Home and Away already.

You can see here that all of the Oasis products are a very thick consistency. I know that with oily skin I have better success with lighter lotions rather than heavy creams. What ended up happening when they went on my face is exactly what I didn’t want… they stayed on the surface and didn’t sit naturally. An hour after applying I touched my face and it felt almost tacky. I’m wearing the AA cream under the BB cream in the photo at the top of this post, and you can’t see that it’s not sitting great on my skin, but I think you can see how intense the coverage is.

Because you read this far I am going to reward you with the best/worst/strangest blogging outtake photo ever. What am I even doing?

So, where to from here? I’m not going to be purchasing any full size Oasis products but I’ll definitely use up the basic sunscreens while I’m still looking for my sunscreen holy grail. (That’s another buzzy thing: it’s illegal to call it ‘sunblock’ because it implies that it 100% blocks the sun!) I’ve tried a couple of samples I found in my skincare sample drawer but none of those have completely satisfied me either. If you’ve got a facial sunscreen you’re a fan of, please let me know in the comments!

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