As summer starts, one of the essential products in our toiletry bags is, without a doubt, sun cream. However, we are often perplexed by the variety of numbers on the packaging.
What does the number on the sunscreen really mean, and how does it affect our protection?
The number we see on the label of our sunscreen is called the Sun Protection Factor (SPF). This indicates how much longer we can stay in the sun without getting sunburnt, compared to not wearing sunscreen. For example, if you normally burn after 10 minutes in the sun and you wear SPF 30, you could theoretically stay in the sun 30 times longer, i.e. 300 minutes, without burning.
It is important to note that SPF does not translate into protection proportionally equal to its number. An SPF 30 blocks about 97% of UVB rays, while a factor 50 blocks about 98%. As we can see, the difference between these two is not very significant. The choice of the right SPF depends on several reasons, such as skin type, intensity of sun exposure and environmental conditions. People with fair skin or a history of skin cancer should opt for a higher SPF. Also, on cloudy or windy days, the intensity of the sun's rays should not be underestimated.
As a tip, it is essential to apply the cream 30 minutes before exposure to the sun and reapply every 2 hours, or more often if you are swimming or sweating. Also, do not rely on sunscreen alone to protect you from the sun; it is important to supplement with hats, sunglasses and shade when the rays are at their strongest. Understanding what the number means is key to making informed decisions about our sun protection. By choosing the right SPF and following good application practices, we can enjoy the sun safely and keep our skin protected from UV damage.