Sun exposure has lots of benefits, especially in what concerns bone health and tanning for those who enjoy having a tanned skin, but it also comes with a lot of dangers. Sun radiation is responsible for sunburns, premature aging, skin cancer, photoallergies, phototoxicity and many other issues that can be just transitory or can have a deep impact in life. So let’s take a look at how solar radiation affects the skin and how sunscreens work to protect it.
Solar radiation and the skin
Solar radiation is comprised of a combination of different radiations, namely ultraviolet (UV, which can be decomposed in UVA, UVB and UVC), visible light and infrared (IR). Some of them never reach the skin due to the filtering system of the atmosphere, like the UVC radiation, but most radiation still reaches the surface of the Earth. This means that all that radiation will reach our skin and will affect it in several different ways, due to the fact that they all reach different layers of the skin.
Although UVB radiation is responsible for the sunburns and the visible harmful effects, UVA and UVB together are the main cause of melanoma, meaning that you may not see that the UVA is reaching your skin because the effects are not visible, but it is still damaging your DNA. This matters because not all sunscreen ingredients protect against all radiation, but we’ll cover that further below.
What you need to retain about sun radiation is this: all the radiation induces photoaging, as even visible light and IR have been proven to induce collagen breakage, dark spots and wrinkling; UV light is the main responsible for melanoma and UVB radiation induces sunburn.
How do sunscreens work?
Sunscreens protect against the solar radiation via two different methods depending on the ingredients used. Mineral sunscreens offer physical protection, which means that they reflect the radiation, stopping it from reaching the skin. However practical, these sunscreen ingredients are the ones responsible for the white cast, as the skin is reflecting the light – however, the industry has now developed micronized particles that reduce this white cast. Organic sunscreens offer chemical protection by absorbing the radiation and can protect against a very large spectrum of radiation. In the past, these organic sunscreens were not very popular because many people developed allergies when using them, but the ones being used in the present days have surpassed those issues and are extremely safe – but they are only recommended for people over 3 years old. The best sunscreens tend to combine both these ingredients in order to offer the most effective protection possible, but it is possible to find sunscreens with only mineral formulas.
What is SPF and what SPF should I use?
SPF stands for Sun Protection Factor and it represents the amount of UVB radiation it protects from. However, as we’ve discussed before, even though UVB is the main perpetrator concerning sunburns, UVA is the main responsible for melanoma, which means that reading the SPF isn’t enough to know that you’re protected against melanoma. Since our store is located in Europe, all our sunscreens must respect the current law in Europe, which states that the UVA protection has to be at least one-third of the UVB protection – this is one of the reasons why our American customers love to shop our sunscreens, as their laws do not contemplate UVA protection and they could be buying SPF50 that does not at all protect from UVA radiation.
Also according to the European law, sunscreens produced and sold in Europe cannot state an SPF over 50. This is because the increase in protection is not linear, as you can see on the chart below:
The recommended SPF should be no lower than SPF 15, but as you can see, SPF15 corresponds to 93% protection and SPF30 corresponds to 97% protection. This means that for every 100 photons that reach the skin, SPF 15 is able to ensure that 93 doesn’t harm the skin and SPF30 ensures that 97 are either absorbed or reflected. Europeans lawmakers saw this and concluded that there is no clear benefit from SPF over 50 – so they recommended that the brands do not use higher SPF as a way to induce people into thinking there would be a clear increase in protection. Brands are still able to produce sunscreens with an SPF over 50, they are just not allowed to use that as a marketing bonus. All SPF products that contain more than SPF50 are stated as SPF50+, so you may find your usual product that you buy as SPF60 outside Europe, with the exact same formula being sold here as SPF50+. Some brands have even chosen to use the percentages of protection instead of the SPF nomenclature.
SPF15: protects from 93% of radiation and is suitable for people with darker skin tones.
SPF30: protects from 97% of radiation and is suitable for olive toned people and people who do not burn easily.
SPF50 or over: protects from 98% of radiation and is suitable for people who have fair skin tones, burn easily and/or suffer from medical conditions that are affected by sunlight, like rosacea.