There is a popular misconception among people that higher the Sun Protection Factor (SPF) of a sunscreen, the better it will be able to protect against sunlight. While this may be true in theory, practically it is not possible. There have been several studies that have proven that sunscreens with SPF 50+ are just as effective as a sunscreen with an SPF 30.
What is SPF?
SPF or Sun Protection Factor is a formula to measure a sunscreens\’ ability to protect the skin from damage by UV radiation from the sun. If your skin burns after 20 minutes under the sun, a sunscreen with SPF 15 will protect your skin for 15 times longer. Thus, you can stay in the sun for 300 minutes without getting damaged.
Sunscreens with SPF 15 and above generally provide superior protection against UVB radiation of from sun. Generally, SPF 15 filters out 93% of UVB rays, SPF 30 filters 97% and SPF 50 filters 98% of UVB radiation.
Not all sunscreens that protect against UVB rays, protect against UVA rays. Therefore, it is important to check if the sunscreen has UVA protective ingredients like avobenzone, oxybenzone, mexoryl, zinc oxide and titanium dioxide.
Efficiency of Sunscreens
The efficiency of sunscreens depends on how you use the product more than their SPF. Here are some tips to apply sunscreen so you can extract the maximum benefits.
- Apply sunscreens all over every exposed area of your body at least 15-20 minutes before you go out in the sun so that it is absorbed well into the skin.
- Reapply the sunscreen every two to four hours or whenever possible, especially after physically stressful activities like exercising, swimming, hiking, etc.
- Apply a thick coat of sunscreen so that you are well protected against the harsh UV radiations of the sunlight.