“We have been told numerous times to use sunscreen when we’re going out in the sun… but do you really know if the sunscreen that you purchased will protect you against the sun’s harmful effects?” Asks Dr. Stan Green from Specialist Clinics of Australia in Sydney.
What is the best type of sunscreen? Is there such a thing as “best”? In this blog post, we will look into various elements that you should consider when buying sunscreen.
What are UV rays and how do they affect me?
There are 3 types of UV rays, but only 2 of them that actually reach us:
– UVB rays – these rays are characterized by having more energy and therefore being more dangerous to our health. They’re responsible for sunburns, erythema, dermatome or cataract. However, on the upside, they can be filtered by glass and clouds, therefore their emission is significantly lower during cloudy days, and does not affect us when we’re indoors. The effects of UVB rays are instantly visible.
– UVA rays – these do not cause rapid and instant damage as is the case of the UVB rays. However they do penetrate deep into our skin, causing premature aging, skin cancer, giving us a tan and discolorations. UVA rays’ effects are not noticeable right away. They can penetrate through glass windows and clouds and their intensity is constant, independently from the time of the day or season.
What sun filters should you invest in?
Currently, there are 2 types of filters available. The first are the chemical compounds absorbing the energy carried by the solar radiation, and the second ones are the physical filters that do not allow for the UV rays to penetrate into our skin, working like two-way mirrors. Most sunscreen nowadays contain both of these filters to give us optimal protection.
Physical filters are non-organic compounds that protect us from both UVA and UVB rays (with more emphasis on UVB rays). They do not lose their effectiveness over time and they are very well tolerated by the skin. These filters do not get absorbed into the skin, but instead create a protective layer on top of it. Because of that property, they can get rubbed off easily and should be reapplied regularly to assure the best level of protection. Formulas that are based on physical mineral filters need a heavier oil base, and because of that can feel heavier on the skin.
They differ from the mineral filters in that they penetrate the upper layers of the skin and their function is to absorb the UV rays, turning the dangerous radiation into safe thermal energy.
What are broad-spectrum sunscreens?
The most effective sunscreens are the ones called broad-spectrum, protecting us from both UVA and UVB rays. Often we will find their abbreviations on the package, such as PPD and IPD. They refer to the level of UVA protection, that is determined by UVA rays causing instant tan (IPD – immediate pigment darkening) and permanent tan (PPD – permanent pigment darkening).
IPD should inform us to what degree the product will protect us from UVA rays (the maximum accomplished is IPD 90, giving us 90% of protection) and PPD tells us how many times the amount of UVA rays absorbed by skin has been reduced.
Should I pay attention to the SFP factor?
Another important matter is the SPF factor indicated by the manufacturer on the package. The higher the factor, the higher the protection, however the difference is not as big as you might think.
SPF is the relation between the minimum doses of UV rays that causes redness on the skin protected by sunscreen, to the minimum doses of UV rays needed to cause redness on unprotected skin. Therefore, if we are using sunscreen SPF 50+, it means that our skin will become red 50 times later than if we were not using any protection.
SPF is the reference for the capacity of a sunscreen to protect us from erythemal properties of UVB rays, and its amount grows along with the concentration of the filters in the product.
Sunscreen with SPF 50 protects our skin in almost 98%, SPF 30 in around 96,7%, SPF 15 in 93,3% and SPF2 in 50%. As we can see, the difference between SPF 30 and SPF 50 is very small, and when choosing sunscreen we should concentrate not just on its UVB protective properties but also those for UVA rays.
Should I consider the photostability of my sunscreen?
It is also important to pay attention to the photostability of our sunfilter, especially if we are going to use it on our face and intend to put make-up later on. Below you will find a list of common stabilisers.
If the suncream of your choice has at least one of them (the more it has, the better), you can put make-up on top of your sunscreen without the fear of decreasing its sun-protective properties:
- Butyl Methoxydibenzoylmethane (PARASOLU1789)
- 4-Methylbenzylidene camphor (USAN Enzacamene)
- Tinosorb M (USAN Bisoctrizole, INCI Methylene Bis-Benzotriazolyl Tetramethylbutylphenol)
- Tinosorb S (USAN Bemotrizinol, INCI Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine)
- Mexoryl SX (USAN Ecamsule, INCI Terephthalylidene Dicamphor Sulfonic Acid)
- Mexoryl XL (INCI Drometrizole trisiloxane)
- Butyloctyl Salicylate
- Hexadecyl Benzoate
- Butyloctyl Benzoate
- Corapan TQ (INCI Diethylhexyl 2,6-Naphthalate, DEHN)
- Oxynex ST (INCI Diethylhexyl Syringylidene Malonate, DSM)
Is there a way to nourish my skin at the same time?
Useful ingredients in sunscreens are antioxidants, such as vitamin C, which reinforce the protective properties of filters. It should be indicated as ascorbic acid on the ingredients list of your sunscreen.
No matter what sunscreen we chose it is vital not to forget to reapply it every 2 hours and to use a sufficient amount of it. “We should read the ingredients list carefully, in order to choose the sunscreen that will best fit our needs but in the end, the best sunscreen is the one that is used regularly,” says Dr. Green.