what does "SPF" mean when you buy a sunblock. and what is the difference between all of the number like 30, 35 , 40,ect...
2007-03-17 12:34:00 · 9 answers · asked by Anonymous in Education & Reference ➔ Trivia
Sun Protection Factor and the 30 35 40 is the percent it will protect you from the sun ( note: if you are going swiming make sure you buy a water proof one or you will still get burned)
2007-03-17 12:38:48 · answer #1 · answered by Anonymous · 0⤊ 0⤋
SPF stands for Sun Protection Factor and is factor that helps understand how much longer we can be in the sun before burning, relative to our tendancy to burn without sunblock
For example, assume that you are a fair skinned person who normally burns in 20 minutes. Proper use of a sunblock with SPF 15 would mean that, assuming it does not wash off, you could remain in the sun for 20 min x 15 = 300 minutes before burning. Realistically, with any activity, the sunblock will not remain on the skin for the full 300 minutes and it needs to be reapplied regularly.
In answer to your question, SPF does not increase proportionally with a given SPF number. An SPF of 30, for example, blocks 97% of sunburning rays, while an SPF of 15 indicates 93% absorption and an SPF of 2 equals 50% absorption.
=)
2007-03-17 19:37:16 · answer #2 · answered by john s 3 · 2⤊ 0⤋
Sun Protection Factor
2007-03-17 19:39:03 · answer #3 · answered by karyn 2 · 0⤊ 0⤋
SPF stands for Sun Protection factor.
If you would normally burn from 15 minutes of sun exposure, SPF 10 would protect you for 10 x 15 = 150 minutes, or 2.5 hours. SPF 30 would protect you for 30 x 15 = 450 minutes, or 7.5 hours.
2007-03-17 19:41:16 · answer #4 · answered by feral_black_gryphon 3 · 0⤊ 0⤋
sun protection factor
the numbers stand for the factor of time the sun-block protects you from harmful rays compared to none at all.
i.e. spf 30 means you can stay in the sun 30 times longer than without before experiencing negative effects of the sun
2007-03-17 19:36:35 · answer #5 · answered by Skyhawk 5 · 0⤊ 0⤋
Solar Protection Factor . The higher # the more protection .
2007-03-17 19:38:41 · answer #6 · answered by wouldeye33 2 · 0⤊ 0⤋
I think it means that sun protection factor.
the number means how much it protects the skin.
If the number is big, that helps better, I think.
2007-03-17 20:17:19 · answer #7 · answered by timeworld 2 · 0⤊ 0⤋
IT MEANS SUN PROOF FORMULA AND THOSE NUMBERS MEANHOW MUCH PERCENT IT WILL BLOCK THE SUN
2007-03-17 19:38:17 · answer #8 · answered by Anonymous · 0⤊ 1⤋
im not sure its how protective it is
2007-03-17 23:57:57 · answer #9 · answered by donielle 7 · 0⤊ 0⤋