Question:
I went horseback riding today and applied a *liberal* dose of SPF 15
sunblock on my face. It was hot, but I know I didn't sweat it off. I
was out for three hours (between noon and 2pm) so I admit it was during
the peak UV hours...However, I was wearing SPF 15 and would not have
expected that in that time my face would show any reaction to the sun.
When I got home, I saw a zillion new freckles and a slight burn on my nose.
I have always been under the impression that SPF 15 is the highest
necessary sunblock and any higher is superflous. Well, I just don't know
about this! What gives?
Granted, my arms are lobster red (I should have worn a sunblock on
them also) so by comparison my face is unscathed...but I wouldn't have
expected ANYTHING to get through such a high SPF.
Is there something I don't know? FWIW, I used Physicians Formula
Self-Defense Moisturizer for Oily Skin. (I alternate between this and Oil
of Olay SPF 15, depending on what my skin feels like after washing.)
I also use an 8% AHA gel regularly, but didn't today when I was out in
the sun...I used the sunblock exactly as directed and still got some freckling
and a slight burn.
Answer:
I'm going to assume that your skin burn easily, and that UV intensity
was somehow high (say index 7 to 9). That means that your skin would
start to burn in about 8 to 10 minutes if you were not wearing any
protection.
If you read any sunscreen label, you are going to read that SPF X
provides X times the natural protection. You said you wore SPF 15.
That means that you could stay out 15x longer than without protection
before your skin starts to burn. In theory, you could've stayed in
the sun for about 120(15x8) to 150(15x10) minutes. But you said you
stayed out for 2 or 3 hours. Your skin was burning for as much as 30
minutes in the 2 pm sun! That's how you got the freckles and nose
burn.
I said "in theory" because this is an ideal case. Keep the following
in mind:
- The SPF labeled is usually an ideal case. You might not get exactly
15x protection from SPF 15. Don't push your luck by staying too long
under the sun.
- Most people I know don't put enough sunscreen. I don't know if
that's your case.
- After applying, you should wait at least 30 minutes before going
out. The sunscreen needs to bond with your skin *before* you go out;
otherwise, you might not get the protection you think you are getting.
- AHA might make your skin more sensitive to the sun.
- As shown by my example, SPF 15 is not nearly enough for outdoor
sports, especially if you have sensitive skin. A research released a
couple of months ago found out that cyclists need at least SPF 22
sunscreen to get adequate protection from the sun. I have fair Asian
skin, and it does not easily burn just tans, and as a cyclist I find
that SPF 15 is ridiculous. I only ride after 5PM, and I never go for
a ride wearing anything less than SPF30. I'm using SPF45 now, and I'm
still getting a tan (very slowly obviously).
All that being said, I have a case for not wearing high SPF, besides
they being more expensive. *Based on my own experience*, if you are
acne-prone, the higher the SPF the more likely you are to have break
outs.
