If you have ever purchased a bottle of sunscreen, you have probably asked the question What is SPF?, SPF is an acronym for “Sun Protection Factor” and it is designed to help us estimate how long we can remain exposed to the sun without getting burned.
Sunscreens and their corresponding SPF numbers were created back in the early sixties as a way to measure the effectiveness of various lotions in stopping the damaging effects of ultraviolet rays on the skin. The sun is known to emit a couple of different kinds of rays. Ultraviolet A, or UVA rays, are long waves, and ultraviolet B (UVB) are short waves.
In simple terms, UVB waves are recognized as those that generally cause sunburn, while UVA waves are often connected with more long term skin damage. SPF numbers identify a sunscreen’s ability to guard against these sunburn-causing waves.
What is SPF – Why it is Important
The need for sunscreen is very important as the ultraviolet rays produced by the sun are capable of changing the DNA of the skin. This can often lead to genetic mutations in the structure of the skin’s layers and that can eventually manifest into cancer.
The World Health Organization and other groups have identified ultraviolet radiation as the leading cause for multiple types of skin cancer such as melanoma. Overall, its negative health effects impact more than one million people around the globe every year.
What is SPF – The numbers
SPF numbers were essentially designed as a way to measure the stopping power of sunscreens in blocking these dangerous UV rays. These numbers are not 100% accurate but can give a consumer a good idea of how long they could be protected from long term exposure to the sun.
The system is somewhat subjective in that you take the average amount of time that it would normally take you to burn in the sun and multiply those minutes by the SPF number to determine a “safe” exposure window. In addition, the scales don’t really take into account your current activity levels, type of clothing being worn, and other key things that could detract from its ability to protect your skin.
As an example of how it works, if you would normally start burning after a period of 10 minutes in the sun, a SPF 30 sunblock would potentially offer you about 300 minutes of protection.
In simple terms, the answer to “What is SPF” comes down to how long it takes the sun to redden your skin once the sunscreen is applied. The higher the SPF number, the longer this process will take. Again, this measurement is critical because once the skin begins to redden, sunburn and other far more damaging effects can result soon after.
In the end, it’s far more important to have a complete understanding of ultraviolet light and how it may lead to some serious health problems in the future versus answering the What is SPF? question. Skin cancer is a very serious disease and it’s crucial that you protect yourself from UV rays whether you are indoors or out.