What does SPF 30 mean?
SPF stands for sun protection factor. Higher SPF numbers would allow a person to be in the sun longer without burning. SPF 30 means that your skin will not burn until it has been exposed to 30 times the amount of solar energy that would normally cause it to burn. In other words, if you start to burn at 10 mins, applying an SPF 30 would know take 300 mins. to start burning (30x10= 300). However, there are many limitations to this rating (time of day, skin type, uv index, sunblock brand, water, sweat etc...) Also, SPF is just the protection factor against sunburn or UV B radiation and does not have any relation to UV A radiation, which causes long term skin damage.
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Answer . Yes. But very, very, slowly. It will take you twice as long than if you used Spf 15.
SPF 50 stands for Sun Protection Factor 50, so if the normal time to get burnt is 20 minutes you will be safe for 50 times that.
From the Journal of The National Cancer Institute: According to Weinstock, the cap on SPF labeling is not a major issue for the public as a whole. "I think that if the gene…ral public uses SPF 30 or greater, that's sufficient." As Weinstock explained, SPF is a reciprocal function: SPF 15 lets in 1/15 of the burning rays; SPF 30 lets in 1/30; and SPF 50 lets in 1/50. Therefore, the difference between SPF 30 and SPF 50 is only a difference of 97% effectiveness versus 98% effectiveness. "That little bit may be important to some people who have particular sensitivity," said Weinstock. "But, to the general public, it really is not that critical." Remember that SPF30+ sun cream will block out 97% of the sun's rays. SPF50+ will block out 98%. There is NO bearing on the DURATION you can put the sun screen on and expect protection. The issue is that people generally don't put on enough, so they're only getting around 50% protection because of their own vanity. The more you put on, the closer you get to the full coverage offered by the cream. If you use an SPF30+ cream you'll only get a little less protection than the 50, but you need to use enough. The SPF isn't the issue, it's the usage.
SPF means SPF
Sun Protection Factor
The higher the number the greater the protection
spf 30 is for lighter skin
It can last up to around 1 day, but that's pushing it. you should really re-apply yourself with spf30+ every 1 1/2 - 2 hours Hope this helped
SPF stands for Skin Protection Factor. 45 is the level of protection it produces. 45 is quite a good SPF. It is mainly used in sun creams.
"The sun protection factor of a sunscreen is a laboratory measure of the effectiveness of sunscreen --- the higher the SPF, the more protection a sunscreen offers against UV-B… (the ultraviolet radiation that causes sunburn)."
The protection lasts as long as the sunblock is still on your skin.But of course, it will get washed off the next time you shower.Chances are it will last only for a day. Most… sunblocks only last1-2 hours before you need to re-apply them. Exposure to the sun,water, sweat and physical actions such as clothing rubbing againstthe skin all tend to wear out or wear off the sunblock
it is sun protection field
In Skin Care
i think no...because...upto 15 spf...those included moisturizer...nd oily skin have so much in winters specially...
sun protection factor. Its a fairly arbitrary number symbolizing the protection given to your skin from UV rays when applied properly.
The Sun-protection factor system measures the length of time asunscreen will protect your skin from reddening / burning from UVBrays, compared to how long your skin would take… to redden/ burnwithout sunscreen protection.
In Skin Care
It means Sun Protection Factor . In basic terms, it's supposed to indicate how many times the lotion is supposed to improve the sun-blocking capability of your skin. So an SP…F of 30 means applying it to your skin should normally improve your skin's ability to avoid sun damage by 30 times. This factor is an average and based on the skin tone of the average person, but it provides a means to know how strongly a sunblock will protect you.