The very best way to protect your skin and slow down ageing is to wear a broad-spectrum SPF every single day, regardless of the season, temperature or weather.
The first time I was told this I was 26, and I’d just had a facial analysis UV scan that revealed a lot of damage beneath the skin. I was told to wear SPF 50 every day, even though SPF isn’t the only important measurement when it comes to protecting your skin. SPF measure the protection from UVB, but not UVA. Let me break it down…
UBA rays explained
The sun emits three types of UV rays: UVA, UVB, and UVC. The latter doesn’t make it past the ozone layer, so let’s forget about that one. UVB rays is what tans and burns (think B for burn).
UVB radiation cannot penetrate deeply into the skin so the damage done tends to be on the surface, causing skin to tan or burn — and the main cause of most skin cancers. The amount varies depending on the season and where you are in the world. SPF is the rating of protection from UVB.
What is SPF and how does it work?
It stands for ‘sun protection factor’. It increasing the amount of time you can be in the sun without burning by the number. So, if you can last 20 minutes in the sun without burning and then you put on SPF15 then you can times the 20 minutes by 15 and be in the sun for five hours without burning.
This is still a slightly vague measurement because you may not know exactly how long you could last until burning, so your calculations might not be accurate. It will also be affected by sweat and water.
UVA rays explained
These rays are present all year, all over the world. They can penetrate clouds and even glass. They can go much further into the skin then UVB, causing cellular damage that results in ageing and sometimes hyperpigmentation. In fact, 80% ageing is thought to be caused by UVA (think A for ageing).
If there is daylight, there is UVA — these rays are present all year, regardless of the season, weather, or location in the world — that is why you need sun protection every single day.
What protects from UVA?
A ‘broad spectrum’ SPF means it also protects from UVA. In Europe, this rating is done using stars, with five being the highest. In Asia, a PA measurement is used with PA++++ offering the highest UVA protection.
Physical sunscreen uses titanium dioxide and zinc oxide to block the sun, and these ingredients are broad spectrum (and cause less damage to coral reefs) so it is a great choice. However, they often appear white so can be tricky for people of colour.
Do you need SPF if you have dark skin?
Yes. Research has shown black people have a natural SPF of around 13 which slowly decreases with lighter skin tones reaching the lowest of around 3. However, dark skin tones are more prone to hyperpigmentation which can be caused by sun damage and so a broad-spectrum SPF is still really important. While I go for factor 50 most days, people with dark skin can definitely go lower.
Also, despite the fact black people have a natural SPF of around 13, the myth that they do not need sun protection has actually led to them being more at risk of skin cancer. Black people are more likely to die from skin cancer because they don’t expect it, and so seek medical help much later.
What is the difference between mineral and chemical SPF?
Mineral sunscreen (aka physical SPF) contains zinc oxide and titanium dioxide which are small particles that sit on the skin’s surface, whereas chemical sunscreens allow UV light into the skin and then convert it into heat, and the heat dissipates from the skin.
Physical protection tends to last a bit longer in direct UV light purely because the formula is thicker and takes a bit of effort to rub in. It’s generally favoured by people with sensitive skin as its free of parabens, dyes and fragrance free.
Which is better for the environment?
Physical! Chemical sunscreen include the ingredients (such as oxybenzone and octinoxate) which damage coral reefs — in some places they have been banned altogether, such as Hawaii.
When should you apply broad-spectrum SPF in your skincare routine?
It should be the last thing that does on your face. Using antioxidants in the morning earlier in your skincare routine will also help prevent UV damage, like Vitamin C, E, ferulic acid ort resveratrol.
Can I just use a moisturiser with SPF?
Opinion is very divided on this. From my own research and experience, I believe it is more worthwhile to get a moisturising SPF, then a moisturiser with SPF. This way you’re more likely to be able to get a high factor with good UVA coverage.
A lot of skincare brands have chucked a low SPF into their existing products, because the fact we need it every day is becoming common knowledge. I’ve been told by specialists that the efficacy of moisturisers with SPF is questionable.
How often should you reapply sunscreen?
Despite the SPF rating giving a rough guide, there isn’t one for UVA and so common consensus is that if you are outside or by a window it should be applied every two hours. This might seem excessive, but it’s all about habit. I can hold my hands up and say I don’t reapply every two hours on the dot, but I do put more on regularly throughout the day because I sit by a window while I work.
How can you tell if sunscreen has expired?
All skincare and beauty products should have a ‘Period After Opening’ symbol on. The numbers tell you how many months a product lasts after it has been opened. Annoyingly, this is sometimes on the box, and the box usually gets chucked away. Most sunscreens state six, nine or 12 months. If it has never been opened, it will last three years.
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