We know that the sun can damage our skin during summers from dryness and dehydration to
tanning and sun spots to worst case conditions like skin cancer.
No matter what your concern is, you know that you have to shield your skin from the harmful
effects of the sun by using a sunscreen. But, is your sunscreen really effective against the
dangers of the sun? Let’s find out by understanding how a sunscreen works.
Why do you need a sunscreen?
Ultraviolet (UV) radiation from the sun reaches the earth in the form of UV-A and UV-B rays.
The UV-A rays can cause premature ageing of the skin and pigmentation, which is commonly
seen during summers. UV-B rays can cause skin tanning and in the worst case, can also lead
to skin cancer. But, before you pick a sunscreen, there are few things you need to know.
What is the meaning of SPF, UV-A and UV-B?
SPF stands for ‘Sun Protection Factor’ which is a number usually ranging from 15 to 50. What
does this mean? This is an indicator of how much your skin is protected from the harmful UV-B
rays. So SPF 15 blocks around 95% of UV-B radiation while SPF 30 blocks around 97%.
You can also get a sunscreen with SPF 50 in the market, which is known to block around 98%
of UV-B rays. Remember that no sunscreen offers 100% protection against UV radiation.
Typically, most dermatologists in India recommend that you use a sunscreen with at least SPF
30 to prevent sun damage.
Although SPF refers to protection against UV-B radiation, it is also important to look for a
sunscreen that offers UV-A protection. For UV-A protection, you need to look for the PA+
(Protection Grade) rating, which determines the extent of UV-A protection by a sunscreen.
This rating ranges from + to ++++ which indicates whether it protects against medium, strong or
very strong UV-A rays. In India, a sunscreen with ‘++’ rating is usually recommended.
The American Academy of Dermatology recommends a sunscreen that offers broad spectrum
protection, which means it protects from both UV-A and UV-B radiation, has an SPF of 30 or
higher and is water resistant.
Don’t forget to protect your lips
Lip care is mostly an afterthought in our skincare routine, especially during summers. But
summers can be harsh on the lips too. To take care of your lips during summers, make sure you
use a lip balm that contains sunscreen with SPF 30.
Tips to use sunscreen effectively
– How much to use: An FTU o Fingertip Unit is used to measure the amount of cream that
covers the end of the finger to the first crease of a finger. For the face and neck, use 2.5 FTU.
To cover the other exposed parts of the body, you need an ounce of sunscreen, which is
sufficient to fill a shot glass, according to the American Academy of Dermatology.
– When to apply: Always apply sunscreen around half an hour before going out because it
takes at least 30 minutes for the chemicals in a sunscreen to get absorbed and start working.
-Why to reapply: If you are going out, playing sports or exercising outdoors, it is advised to
re-apply the sunscreen every two hours. The same rule applies when you go swimming.
-How to store: Usually, it is recommended to store in a cool, dry place, away from sunlight.
Also, do remember to close it properly after every use.
-When to discard: Do not use a sunscreen that has passed its expiry date or if there are any
visible changes in the sunscreen such as a change in color, smell or consistency. It is advised to
buy a new one every year.
With inputs from Dr. Smriti Naswa, Dermatologist, Mumbai.