Sunscreens are products which prevent ultraviolet rays from being absorbed by the skin. they are available in the form of creams, gels, lotions, sprays and now even capsules.
Let us first understand these rays. Solar radiation comprises UV rays, visible light and infrared rays.
Wavelengths less than 320nm are absorbed by the upper layers of the skin., namely the stratum corneum and the epidermis.
UV rays that reach the earth’s surface comprise UVA (320-400nm) and UVB (290-320nm) rays. Visible rays are at about 400-800nm and infrared rays are anything above 800nm.
Now its time to understand the SPF game
SPF or sun protecting factor is a measure of protection from UVB rays. A higher SPF is recommended for Caucasian skin as it is more prone to skin cancer.
|SPF||Proportion of UVB blocked (per cent)|
For Indian skin types, it is essential to look at the PA value which indicates protection from UVA rays.
|PA||Protection from UVA rays|
For regular use, one should opt for a sunscreen with SPF 30 and PA***
- If you have dry skin, use a cream-based sunscreen.
- If u have oily skin, use a gel-based or matte sunscreen.
- For a larger surface areas, use a lotion or a spray.
How much sunscreen should one apply?
|Face and neck||1/2 teaspoon (3ml) of sunscreen|
|Each arm||1/2 teaspoon (3ml) of sunscreen|
|Each leg||1 teaspoon (6ml) of sunscreen|
|Feet||1 teaspoon on both feet|
|Back||2 teaspooons to full back|