We all know that the best way to protect our skin from the harmful rays of the sun is to use a sunscreen. But how many of us actually use a sunscreen in the right way? How many understand the sunscreen jargon of SPF, broad spectrum, chemical vs mineral etc? With this post, I hope I can help you understand these things so that when you buy sunscreens, you can make an informed choice rather than simply be influenced by advertisements. The idea of writing this post occurred to me when I was working on the Face Masks post (read it here).
What is a sunscreen?
Simply put, a sunscreen is “a lotion, spray or gel, or other topical product that absorbs or reflects some of the sun’s ultraviolet radiation on the skin exposed to sunlight.”
Sunlight is made up of different types of rays. There are the Infra Red rays, the Visible Rays and the Ultraviolet (or UV rays). The ultraviolet rays are of three types:
UVA – These rays are the ones that are responsible for photo-aging (dark spots, wrinkles, freckles are all signs of photo aging). As you can see from the picture, these rays constantly filter down to earth all through the day. In fact, these account for a whopping 95% of the UV rays reaching down to earth and they are also capable of penetrating the deepest into the skin. Along with photo aging, UVA rays also contribute to skin cancer.
UVB -The B stands for Burning as these are the rays responsible for sunburns. When the skin becomes red and scaly, or basically burns on prolonged sun exposure, these are the rays to be blamed. Although only 5% of the UV rays are UVB, they can cause severe sun burns as well as skin cancer.
UVC – So far, people haven’t been too concerned with the ill effects of the UVC rays since our Ozone layer blocks them and prevents them. However, with the gradual depletion of the Ozone layer, there are studies under way to know what damage these rays are capable of causing.
The SPF in a sunscreen stands for the Sun Protection Factor or the ability of the sunscreen to protect the skin from the UVB rays. Yes, only the UVB rays. While most people consider the SPF while buying the sunscreen, they forget that the SPF factor only protects the skin from burning, not from the aging and photo damage caused by the UVA rays.
How the SPF works is basically this; say for example, your skin burns after 15 minutes of exposure to the sun. Applying a sunscreen with SPF of 30 will protect your skin from sun BURN for 15 x 30 = 450 minutes or about 7.5 hours. This is adequate protection for a whole day. So those of you who buy sunscreens with SPF of 50 and above are actually not giving your skin any more protection than you’d get with SPF 30. And this is anyway a very relative calculation. Different skin types handle the sun differently, some burn very soon, others, like our Indian skin, tend to tan easily but not burn that fast. Hence buying a sunscreen based on just a high SPF won’t do our skin much good.
No, I’m not talking about the movie, I’m talking about the PA ranking on the sunscreen which is usually flowed by a couple of ++ signs and which is a more important factor to consider when buying sunscreen than SPF.
The PA stands for the ability of the sunscreen to protect the skin from the UVA rays; the rays responsible for aging. The rays that give us sun spots, freckles, wrinkles, tan etc. The more the number of + after the PA, the better protection from UVA rays.
Sunscreens that offer protection from both, UVA and UVB rays are called “broad spectrum” sunscreens and the packaging will have something like “SPF 30 PA+++” mentioned on it. This is just an example, the SPF number and PA pluses can be more or less, but now you know what to look for.
Waterproof / Water Resistant
Because the sun’s rays, especially the UVA also penetrate water, sun protection is required even during swimming, snorkeling, surfing etc. The term waterproof was earlier used to denote the sunscreen’s efficacy even in water or after sweating. However, the FDA in USA doesn’t permit the use of the word waterproof now since it is misleading. If the sunscreen is water resistant, it has to mention whether it is resistant upto 40minutes or 80minutes. In India, we don’t have any such rules or guidelines so brands still use the words waterproof and sweat-proof. Ultimately, no matter what sort of sunscreen you use, the best way to ensure protection is to reapply after swimming!
Mineral vs Chemical Sunscreens
This is something most people are unaware of. Yes, there are two types of sunscreens and they differ in the chemicals used as well as the manner in which they “tackle” the UV rays.
Chemical Sunscreens are the ones almost all of us use. Most sunscreens available in the market are chemical Sunscreens. These sunscreens usually have certain chemicals that form a layer on the skin and absorb the UV rays before they interact with the skin.
Mineral or Physical usually have either Zinc Oxide or Titanium Dioxide. These work by reflecting the UV rays rather than absorbing them and hence are considered to be a safer option. You must have seen cricketers applying white stuff on their lips or cheeks or noses during a match. Well, that is pure Zinc Oxide and they use it since it scatters the rays rather than absorb them. Several physical /mineral sunscreens are now using nano particles of Zinc Oxide / Titanium Dioxide to reduce the white cast and greasiness traditionally associated with mineral sunscreens.
All of us, every single one of us, makes this mistake. We simply don’t apply the right amount of sunscreen! This picture should hopefully give you an idea of how much sunscreen is needed for optimum protection…
To Sum It Up….
I hope this long post has been informative for you. Depending on your skin’s requirement, you can now choose the kind of sunscreen you need. Easily burn? Go for a higher SPF. Tan easily or get freckles real quick? Make sure your sunscreen has PA+++. With regards to chemical vs mineral, there is no conclusive evidence as to which one is better though several studies lean towards the mineral ones. However, the most important thing is to use sunscreen, everyday, especially in hot, tropical countries such as India. Remember, staying indoors doesn’t offer protection from UVA rays. And yes, please do use the adequate quantity.
Do let me know what you thought of this post in the comments below. Looking forward to your comments and questions.