We regularly stress on the importance of wearing a broad spectrum sunscreen to keep skin protected from the harmful UV rays of the sun. We advise our readers to wear sunscreen throughout the year because of its many benefits. However, like most people if you too are confused about the term SPF and what the numbers associated with it indicate, we’re here to clear all your doubts.
What is SPF?
SPF or Sun Protection Factor, indicates the ability of your sunscreen to protect skin from radiation that can cause sun burns, skin cancer and signs of aging. However, lately most people are under the impression that higher the number of SPF higher the protection offered. This is not true because the sun protection factor scale is not linear.
How is SPF calculated?
SPF 15 blocks 93% of UVB rays
SPF 30 blocks 97% of UVB rays
SPF 50 blocks 98% of UVB rays
SPF 70 blocks 98.5% of UVB rays
SPF 100 blocks 99% of UVB rays
How to apply sunscreen?
On a normal sunny day a SPF 30 sunscreen which blocks 97% of UVB rays is ideal for your skin, irrespective of your skin type. Many skin experts recommend an SPF 50 sunscreen because we don’t wear a thick enough layer to keep our skin protected. When it comes to sunscreen reapplication is important every 2 hours because its effective wears off with time. High level of physical activity demands more frequent application, for example swimming which can wash off the sunscreen from your skin easily.