Protecting the Face/Skin

[violette]

Does anyone use the sunblocks for kids, spf 50? I thought they would work.

[KnottedYet]

I do. I like the ones with a mix of physical and chemical blocks, and those are most often the ones for kids. Banana Boat and Hawaiian Tropic are my favorites.

[BleeckerSt_Girl]

Knotted, I have that Neutrogena titaniumoxide-only sunblock lotion too. It's the one I switched to after the hives episode. It seems fine.
But i just got a tube of Dr. Hauschka's non-chemical sunblock SPF 15 (Tit.dioxide+zinc ox.). Very expensive, but I like the emollient qualities it has, and the smell is pleasing to me. (I had to get rid of some sunblocks I tried because even the "non-scented" ones had aromas I found unpleasant after a while. I have dry face skin and the Dr. H's seems to help that more than the Neutrogena which is "thinner".

I read somewhere that once you get to spf 15, adding higher spf numbers doesn't really multiply the effectiveness mathematically the way you think it does. Sort of like how 1% milk does not have half the fat of 2% milk, like you would expect it to.
Can't remember where I read about it though. Anyone else read that?
I do know that I've never noticed a protection difference between say a 20 and a 35 at all.

[KnottedYet]

The spf is most important relative to each person's burn time.

For example, I burn after about 10 minutes of direct midday sun exposure.

An spf 2 will let me be in the sun twice as long before burning: 20 minutes.

spf 15 gives me 2 1/2 hours

spf 30 gives me 5 hours

spf 50 gives me a bit more than 8 hours, which is probably longer than I'd be in real direct sunlight anyway.

For someone who doesn't burn for 20 minutes, an spf of 50 would just be over kill, and even an spf of 30 might be too much.

My cancer-man pushes spf 30 for everyone all the time. I'll go as low as 15, but no lower. (but I do hats and clothes with it if I'm just wearing spf 15)

[BleeckerSt_Girl]

Yes that sounds like what I had read! So in effect, if I put some spf 15 on my face every 2 hours while in the sun and am in the sun for 6 hours, it will give me the same burn protection as if I put on some spf30 ONCE and stayed in the sun for 4 hours. Now i recall that you don't need the higher spf number if you re-apply some every 2 hours or so. I am leery of overly strong stuff on my skin- but yes I don't want skin cancer either! So the 15 should work fine for me if I reapply if staying out more than 2 hours.

[KnottedYet]

Weeeeeellll, sort of.

You are still absorbing radiation. I can put on spf 2, and in 20 minutes I will have absorbed as much radiation as I would have in 10 minutes naked. So I will burn. If I reapply the spf 2 after 20 minutes, I will still be burned. Because I've absorbed that radiation already and in 20 minutes more I will absorb that much again.

10 minutes naked = burned Knot
20 minutes with spf 2 = burned Knot
2 1/2 hours with spf 15 = burned Knot

but:
10 minutes naked = burned Knot
20 minutes naked = painful peeling Knot
2 1/2 hours naked = blistered crying Knot

The spf cuts down on the amount of radiation you absorb, but you are still getting radiation. The rating is based on how much radiation is being cut off, not how long it will totally protect you.

You need to reapply chemical screens because they break down with exposure to radiation (the radiation destroys the screen instead of destroying you). You need to reapply just to maintain the spf you originally had with your fresh application.

Physical blocks don't break down with radiation, so reapplying them if the previous layer hasn't worn off CAN be cumulative. I always assume it's wearing off, so I end up wearing probably a lot more spf than the bottle says.

[liberty]

Wow. I didn't know I should be rotating the sun protection. What a great thread. I am learning tons. So, sun mentor extraordinaire KnottedYet, how many products do you use and how often do you rotate? Very interested in your review of the new products you mentioned.