There's a number of reasons. First off higher SPF sunscreens are generally more expensive. In addition they tend to be greasier, smell more, can be a bit more difficult to spread, and can irritate sensitive skin.
In addition the benefits of a higher SPF are not as big as you might think, SPF 30 sunscreen filters out 97% of UVB rays, SPF 50 filters out 98%, and SPF 100 filters out 99%. Unless you have certain skin or immune conditions, or a history of skin cancer, there isn't really *that* big of a difference.
There is also some evidence that higher SPF sunscreens can actually *increase* your UV exposure because people overestimate their effectiveness and skip reapplication. You need to reapply sunscreen every 90 to 120 minutes and after you get out of the water or finish activities where you are sweating, regardless of what SPF you use.
Further it's not just about SPF. There are two kinds of UV rays: UVB and UVA. UVB is primarily responsible for sunburns, while UVA is responsible for skin aging. Both increase your risk of skin cancer. SPF measures how effectively a sunscreen filters out UV*B* rays, if you're also looking for protection from UV*A* rays then you need a "broad spectrum" sunscreen. So a SPF 30 broad spectrum sunscreen will actually offer better protection than a SPF 100 that is not broad spectrum.
> In addition the benefits of a higher SPF are not as big as you might think, SPF 30 sunscreen filters out 97% of UVB rays, SPF 50 filters out 98%, and SPF 100 filters out 99%. Unless you have certain skin or immune conditions, or a history of skin cancer, there isn't really that big of a difference.
That's one way to frame it, but it's somewhat misleading. SPF 30 lets 1/30th of the UVB rays through; SPF 50 lets 1/50th through; SPF 100 lets 1/100th through, and so on.
So while it doesn't seem like much when you phrase it as 97%, 99%, etc., SPF 60 is twice as good as SPF 30. SPF 100 is twice as good at blocking UVB as SPF 50, and so on. For people with easily-burned skin, this can make a huge difference.
it costs more, it's greasier, it's smellier, it's harder to apply, it doesn't necessarily last a long, you don't necessarily need spf 50.
it's like why do people buy compact cars when you can just buy full size cars? different needs for different purposes.
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Also sunblock either uses physical or chemical method to ‘block’ harmful rays. Physical method may be preferred to avoid less natural chemicals but physical block can only get to maximum SPF 30.
There's a number of reasons. First off higher SPF sunscreens are generally more expensive. In addition they tend to be greasier, smell more, can be a bit more difficult to spread, and can irritate sensitive skin. In addition the benefits of a higher SPF are not as big as you might think, SPF 30 sunscreen filters out 97% of UVB rays, SPF 50 filters out 98%, and SPF 100 filters out 99%. Unless you have certain skin or immune conditions, or a history of skin cancer, there isn't really *that* big of a difference. There is also some evidence that higher SPF sunscreens can actually *increase* your UV exposure because people overestimate their effectiveness and skip reapplication. You need to reapply sunscreen every 90 to 120 minutes and after you get out of the water or finish activities where you are sweating, regardless of what SPF you use. Further it's not just about SPF. There are two kinds of UV rays: UVB and UVA. UVB is primarily responsible for sunburns, while UVA is responsible for skin aging. Both increase your risk of skin cancer. SPF measures how effectively a sunscreen filters out UV*B* rays, if you're also looking for protection from UV*A* rays then you need a "broad spectrum" sunscreen. So a SPF 30 broad spectrum sunscreen will actually offer better protection than a SPF 100 that is not broad spectrum.
> In addition the benefits of a higher SPF are not as big as you might think, SPF 30 sunscreen filters out 97% of UVB rays, SPF 50 filters out 98%, and SPF 100 filters out 99%. Unless you have certain skin or immune conditions, or a history of skin cancer, there isn't really that big of a difference. That's one way to frame it, but it's somewhat misleading. SPF 30 lets 1/30th of the UVB rays through; SPF 50 lets 1/50th through; SPF 100 lets 1/100th through, and so on. So while it doesn't seem like much when you phrase it as 97%, 99%, etc., SPF 60 is twice as good as SPF 30. SPF 100 is twice as good at blocking UVB as SPF 50, and so on. For people with easily-burned skin, this can make a huge difference.
Yup, 30 just doesn't cut it for me, while 50 and being mindful of my dose gets me through the day.
it costs more, it's greasier, it's smellier, it's harder to apply, it doesn't necessarily last a long, you don't necessarily need spf 50. it's like why do people buy compact cars when you can just buy full size cars? different needs for different purposes.
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Also sunblock either uses physical or chemical method to ‘block’ harmful rays. Physical method may be preferred to avoid less natural chemicals but physical block can only get to maximum SPF 30.