Even a dog knows the importance of wearing sun shades. What about us? You know that it is very important to apply your sunscreen on a sunny day but do you know that it is as important wearing sunscreen on cloudy days and to reapply the cream after a few hours? How much do you know about the basics of sunscreen? Most of us know that sunscreens help to filter out the UV light from the sun and the higher the SPF the greater the protection. There are two types of UV light that will cause skin damage. UVA will cause premature aging and wrinkles, while the short wave UVB is primarily responsible for sunburn. Broad-spectrum lotions covers overall protection against both UVA and UVB radiation.
The SPF, or sun protection factor, is an indication of the ability of protecting the skin from UVB. The best sunscreen is the one having the highest SPF number. The sunscreen with SPF of 30 provides a better protection than one with SPF 15. It tells how long it will take for the skin to be sunburned.
For example, if you skin gets sunburned after 10 minutes, wearing an SPF 15 sunscreen would, in theory, allow you to stay under the sun for 150 minutes, or 10 x 15, without getting burned.
However, sunscreen products with SPF more than 50 will provide only a small increment in protection. Sunscreen is no longer effective for more than two hours and require to reapply.
SPF 15 – filters out 93% of UVB rays
SPF 30 – blocks out 97% of UVB rays
SPF 50 – shuts out 98% of UVB rays
In some of the sunscreen product, you will see PA++. PA is the protection grade of UVA system. You will see this rate on most of the Japanese product as it is their measurement of sun protection. There are three protective levels of strength, mark as PA+, PA++ and PA+++. PPD, on the other hand, stands for persistent pigment darkening. It measures a sunscreen’s amount of protection from UVA rays.
PA+ provides some UVA protection with PPD of 2-4. It protects sensitive skin against low to medium UV radiation.
PA++ provides moderate UVA protection with PPD of 4-8. It is used by people with normal skin, exposing to medium UV radiation.
PA+++ provides good UVA protection with PPD of > 8. It is the strongest grade of UVA protection now and designed for normal skin under very strong or direct UV radiation
Here’s a summary which you may find it helpful. Remember, whether is it cloudy day or sunny day, you will need your sunscreen. Your skin will be thankful to you.