What does SPF mean?
You see it on all the sun protection products, whether clothing or sunscreen. It stands for Sun Protection Factor.
SPF is a numerical indicator of how much of the sun's UVB rays are blocked by a product. Generally sunscreens have an SPF as low as 2 or as high as 60.
An SPF of 2 means that this product should allow you to stay in the sun twice as long without burning as you could without any sunscreen. An SPF of 60 means you should be able to stay in the sun 60 times as long.
Keep in mind that these measurements were determined in a laboratory under carefully controlled conditions. It also means the product was used as directed. Most of us do not use sunscreens as directed. Also, I have to emphasize that SPF indicates how much of the sun's UVB rays (the burning rays) are blocked. There is no measure for how effective a sunscreen is against UVA rays (the deep penetrating rays).
We don't use enough sunscreen, we don't apply often enough, and we don't apply it 30 minutes before sun exposure.
Shortly, we'll find out about different sunscreen ingredients and which ones are the most effective, and what is the difference in an SPF 45 and an SPF 60. Sun protective clothing is often a better option than sunscreen.
Sun protective clothing may be just what you need.