rating which determines how many times longer your skin can tolerate UV rays when sunscreen is applied. For example, if it takes you 5 minutes to burn and you use an SPF 15 sunscreen, it should take you 75 minutes to burn (5 minutes times 15 SPF equals 75 minutes).
How many times longer a person wearing sunscreen can stay in the sun before beginning to burn than they would without any sunscreen at all.
A number quantifying the effectiveness of sunscreens. For example, if you can normally stay outside for about 15 minutes before you start to burn, then applying a sunscreen with an SPF of 20 allows you to stay out for 20 times 15 minutes before burning—or rather, 300 minutes. The SPF is measured in the laboratory under standardized conditions, so caution has to be applied when using it to estimate the time one can actually stay in the sun. As many sunscreens only block UV-B radiation, they are not as effective as the SPF suggests in protecting the body from harmful effects caused by UV-A radiation, like photoaging and possibly melanoma.
SPF indicates the degree of protection the sunscreen provides. A sunscreen with an SPF of 4 provides the least protection; sunscreen with an SPF of at least 15 provides the most protection. SPF is based on how long unprotected skin takes to burn when exposed to artificial sunlight.
This is a rating given to sun creams. If you normally burn in the sun after 15 minutes with no sun protection, a lotion with an SPF of 4 will allow you to stay out for 4 times as long - or for one hour - without burning. But you have to put a lot of lotion on to get as much protection as the SPF on the bottle indicates. And you have to reapply regularly and after every swim. If you don't, you will burn and increase your risk of malignant melanoma and other skin cancers. Long term excessive sun exposure also causes the skin to age prematurely.
The SPF is a ratio between the ultraviolet dose required to produce minimal erythema reaction (redness) in protected skin (skin with sunscreen) compared to unprotected skin (skin without any sunscreen). The SPF number indicates how much longer a person can stay in the sun before beginning to burn while wearing sun protection than if he or she were not wearing sunscreen at all. This amount of time varies from one individual to another.
The SPF is the ratio of the time required to produce minimal erythema on skin covered by a sunscreen product to the time required to produce the same degree of erythema without the sunscreen. If you usually turn red after 10 minutes unprotected in the sun, next time you use a sunscreen with SPF 15 you can stay 150 minutes in the sun without getting a sunburn. But this ration may lead to a false security since studies have shown that people using a higher sunscreen tend to stay 20 % longer in the sun which is not necessarily the intention of sun screen.
the number tells you the amount of time it will take your skin to burn with sunscreen compared to the amount of time before you'd burn with no sunscreen. (In other words, an SPF of 8 means you can stay in the sun 8 times as long as you could with no protection on your skin before your skin begins to burn.)
A laboratory measure that grades how much UVB a sunscreen can block. The numbers range from 2 upwards.
a number assigned to sunscreen products, which refers to the ability of a product to protect skin from burning caused by UV-B radiation. If it normally takes your skin 10 minutes to become reddened without protection from the suns rays and you apply a lotion with SPF 15, you should have approximately 150 minutes of protection before burning.
Rating given to sun creams. If you normally burn in the sun after 15 minutes with no sun protection, a lotion with an SPF of 4 will allow you to stay out for 4 times as long - or for one hour - without burning. But, a lot of lotion has to be put on, and regularly reapplied, to get as much protection as the SPF on the bottle indicates. If you do not, you will burn and increase your risk of malignant melanoma and other skin cancers.
Sun Protection Factor, most commonly referred to as SPF, is a number that identifies a product's ability to protect the skin from sunburn. SPF numbering is regulated by the FDA. Since sunburn results from UVB exposure, not UVA radiation, SPF is primarily a measure of UVB protection. At this time, there is no numbering system to indicate the level of protection a sunscreen can provide from UVA radiation, which affects the deeper layers of skin.
used to indicate the effectiveness of sunscreen in preventing sunburn;the number indicates how many times normal one can stay in the sun before burning
the factor for the amount of time greater than normal that it takes ultraviolet light to bum the skin.
Commonly seen on suntan ingredients as "SPF," the sun protection factor is the amount of the protection a suntan product provides. The higher the SPF, the greater the protection.
(SPF) Degree to which a sun cream, lotion, screen or block provides protection for the skin against the sun
A scale for measuring how long a sunscreen protects the skin from UVB rays before sunburn occurs, compared to how long it takes to burn without protection. Sunscreens with an SPF of 15 or higher provide the best protection from the sun's harmful rays.
SPF. A scale for rating the level of sunburn protection in sunscreen products. The higher the SPF, the more sunburn protection it provides.