Sunscreen

With such a wide range of sun protection products in the market, choosing one that works for your skin can be difficult and confusing. 

What do we look at and how do we choose the best sunscreen for our skin?

Sunscreen helps to shield our skin from ultraviolet (UV) rays in 2 ways: 

  • By scattering UV, reflecting it away from us
  • By absorbing UV before it reaches our skin 

There was a time when SPF was the main hype but research has since gone further than that. 

We now know that the 2 main types of UV coming into contact with our skin are: 

  1. UV-A: does not cause sunburn but penetrates deeply into skin and causes wrinkles and photoageing. Also increases the risk of skin cancers
  2. UV-B: burns our skin, reaches only the epidermis, causes skin cancer.  

Let’s dissect the main labels on a sunscreen bottles and what do they mean. 

1. SPF

This is probably the most widely recognized label on a sunscreen bottle, with numbers going ever higher, ranging from 4 to 100+. What does it mean though?

SPF stands for Sun Protection Factor. It is a measure the fraction of UV-B reaching the skin. For example, SPF 15 means that 115 of UV-B will reach the skin, assuming that the sunscreen is applied evenly at a dosage of 2mg/cm2. Thus, if a person normally burns in 10 minutes under the sun, it would theoretically take him/her 150 minutes to burn with an SPF 15 sunscreen. 

However, it is also important to note that sunscreens with higher SPF do not last or remain effective any longer than lower SPF sunscreens, and the general rule of thumb would be to reapply every 2 hours. The scale of SPF is also not linear. 

Image result for SPF scale

Hence, a high SPF does not mean stronger protection. SPF is only a rating for UV-B, and there are other things to look out for, such as UV-A protection, water or sweat resistance that we will discuss further.

2. UV-A protection

There is not a universal rating system for UV-A protection, which leads to even more confusion. 

Below, we will discuss the main UV-A protection ratings used. 

PPD (Persistent pigment darkening)

Originally developed in Japan, this is the method employed by manufacturers such asL’Oréal.

This method uses UV-A to cause persistent darkening or tanning of the skin. In example, a sunscreen with a PPD rating of 10 should allow a person 10 times as much UV-A exposure as would be without protection. 

PA system

In Asia, a common system used is the PA (Protection Grade of UVA) system. This system is basd on the PPD reaction and is now widely adopted on labels of sunscreen. 

PA+ corresponds to UVA protection factor 2-4; PA++ 4-8, PA+++ >8 and PA++++ >15. 

3. Active ingredients

As discussed earlier, sunscreens absorb or refract UV to protect our skins. Typically, a sunscreen will contain at last one if not more types of active ingredients, which can be either chemical or mineral in nature. The important thing here is to look for a sunscreen with broad spectrum sun protection. 

Two of the most common mineral ingredients are titanium dioxide and zinc oxide. They protect the skin by reflecting, scattering and absorbing UV rays. 

Organic compounds on the other hand works mostly by absorbing UV rays although some of them do scatter and reflect a fraction of UV. Ingredients such as these include benzophenones (oxybenzone), avobenzone (Parsol 1789), ecamsule (Mexoryl SX), salicylates, sulisobenzone, etc. 

4. Water resistance

Another important factor when looking at sunscreens. Choosing the right sunscreen for the activity you will be doing is imperative to ensure its efficacy. However, before doing that, we need to first understand some of the labelling related to water resistance. 

“Water resistant” sunscreen is defined by the FDA as sunscreens with an SPF level that stays effective after 40 minutes in water. Similarly, “very water resistance” – 80 minutes. 

5. Mode of application 

These days, sunscreens come in a variety of preparations, examples of which include sprays, balms, gels, creams, powders etc. One of the important factors to look at when selecting a preparation is how it blends in with your own lifestyle. For example, a powdered or spray sunscreen may be suitable for ladies who have make up on, whilst a water resistant cream sunscreen may be more suitable for the outdoors. It should not be the case that one has only one type of sunscreen for all occasions. 

6. Carrier ingredients

The other important factor when looking at sunscreen is carrier ingredients. Increasingly, we are seeing cosmeceutical manufacturers moving into the sunscreen industry, and there are now a myriad of choices of sunscreens that have multiple other ingredients such as anti-oxidants, vitamins, moisturisers that not only protect your skin against the sun, but nourishes as it does so. For daily use, selecting one that acts as your moisturiser may be suitable for people constantly on the go, but of course, for people with sensitive skin, more attention will have to be paid to the ingredients included in these sunscreens. 

With the myriad of choices in the market, consumers are definitely spoilt for choices, but knowing what one is buying, and choosing the right product for your skin type and lifestyle is very important. With this, we are hoping that consumers are able to choose their sunscreens better for healthier and more youthful looking skin. 

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