SPF rating and UV rays
A survey performed on 2,000 adults in the UK showed that 20% of those questioned did not know that their sunscreen SPF rating does not protect them against all forms of sun damage. More specifically, SPF measures how well your sunscreen protects you only against UVB rays; protection against UVA rays is measured in an entirely different rating system.
Both UVA and UVB rays can cause skin cancer, but UVA rays are the ones responsible for skin aging and wrinkles. In the same survey, one in three respondents did not check the UVA rating before purchasing their sunscreen, as they were only concerned about sunburn. More importantly, 25% of the survey respondents said they had no idea about the meaning of SPF on sunscreen labels.
What does SPF mean?
SPF stands for Sun Protection Factor and measures how well a sunscreen protects your skin from UVB rays. The number next to SPF indicates how much longer you can stay in the sun after applying sunscreen compared to the time you remain exposed without protection before your skin starts burning. For example, if your skin burns in 10 minutes after sun exposure, a sunscreen with SPF 30 will protect you for 300 minutes (a factor of 30 times more).
So, the higher the SPF, the longer you can stay out in the sun? It is not as simple as that, as you need to bear in mind the following points:
- SPF measures how much you can be exposed to UVB light and is not intended to help you determine the duration of your sun exposure.
- It is hard to calculate the time it takes for your skin to burn. It depends on how tanned you already are, how strong the sunlight is at the given moment (day and time) in the year, and even how sun-damaged your skin already is.
- The sun will be hotter and stronger at certain times of the day and the year, so judging the right time before burning is tricky.
- Children’s skin is more likely to burn quicker than that of adults, as it tends to be more delicate.
- You need to apply your sunscreen at least every two hours and ensure full coverage of all exposed areas to maximize SPF protection against UV damage.
Remember that there is no full protection against the sun. The best way to reduce the possibility of skin cancer is to avoid prolonged sun exposure and apply sunscreen with high SPF and UVA protection before you go out in the sun.
Don’t forget to check for any suspicious moles to make sure your skin is healthy. Try SkinVision now and get an instant risk indication.