Even though most of us never hesitate to apply sunscreen on holiday or on sunny days at home, digging out a bottle in the winter may not come naturally.
But is it really necessary to wear SPF in any weather? Why should we wear SPF?
What is SPF?
SPF, which stands for Sun Protection Factor, is a measure of how much protection sunscreen products offer against UVB rays.
UVB rays are one of two different types of rays that are produced by sunlight; the other being UVA rays.
Out of the two, UVB rays cause the most damage to our skin, including sunburn. They play the greatest role in causing skin cancers, which includes the deadly black mole form of skin cancer, malignant melanoma.1
Meanwhile, UVA rays can also contribute to skin cancer. They penetrate more deeply into our skin and play a greater role in premature skin ageing, such as wrinkle formation.
There are around 500 times more UVA rays in sunlight than UVB rays. So when you’re choosing sunscreen, it needs to protect you from UVB and UVA rays.
The longer you stay in the sun without sun protection, the greater your chances of burning. The sun in the UK is strongest from March to October, so it’s wise to apply a sunscreen that will provide you with protection of at least SPF15.
Using SPF15 sunscreen every day may reduce your risk of developing squamous cell carcinoma, a form of skin cancer, by around 40%, and melanoma by 50%.2
If you tend to spend a lot of time outdoors - you may work outside, for instance – you should wear SPF 30 or higher, and it should be water-resistant sunscreen too. And don’t forget to reapply it.
Regardless of how strong your sunscreen is, if you sweat or get wet, you must put some more on again, ideally every two hours, to make sure your skin stays fully protected.3
- SPF measures how much protection sunscreen products offer against UVB rays
- Sunlight produces UVB and UVA rays
- They can both cause skin cancer
What is SPF in sunscreen?
The numbers you see on your sun cream or lotion, spray or gel are ratings based on the level of protection they offer. For example, factor two offers the lowest form of UVB protection and SPF 50+ offers the strongest protection.
The number doesn’t relate to how long you can stay out in the sun for. It applies to how much longer it will take skin that’s untanned to start to get red with sunscreen on it, compared to how long it will start to get red without it.4
SPF numbers are calculated using a certain formula – dividing the number of seconds it takes skin to slightly redden when covered in sunscreen by the number of seconds it takes to slightly redden when no sunscreen has been used.
For example – if it takes 300 seconds for skin to burn with sunscreen, and 10 seconds to burn without it. 300 is divided by 10, which is 30 or SPF 30.
While most of us pay attention to SPF, the star rating on our bottle of sun lotion is also important. This measures the amount of ultraviolet A radiation (UVA) protection, with a rating of up to five stars being the highest shown on UK sunscreens.
UVA targets the skin more deeply than UVB and is a key factor in skin wrinkling and ageing.
Choose a ‘broad spectrum’ sunscreen, as this indicates that it offers both UVA and UVB protection.
What does SPF do to your skin?
SPF works by essentially creating a barrier between your skin and the sun’s UVA and UVB rays.
Some contain inorganic chemicals, such as zinc oxide or titanium dioxide, which act as a physical sunblock. They reflect UV rays, similar to how white paint reflects light.5
Sunscreens also contain organic chemicals, such as avobenzone or oxybenzone. Instead of physically deflecting UV light, these molecules absorb UV radiation through their chemical bonds.
As the bonds absorb UV radiation, the components of the sunscreen slowly break down and release heat.
- Factor two offers the lowest form of UVB protection and SPF 50+ offers the strongest protection
- The number doesn’t relate to how long you can stay out in the sun for
- It applies to how much longer it will take untanned skin to go red with sunscreen on it, compared to how long it will start to go red without it
Which SPF should I use?
Just one look at the different sunscreen products available, online and in-store, can be a bit mind-boggling, especially when you need to consider SPF strength and UV star rating, as well as the product type, brand and customer reviews etc.
It is important you do your research when you buy your sunscreen because it does an extremely important job and you want your skin to be as fully protected as possible.
Just as you would take your skin type (normal, dry, sensitive, oily or combination) into account when you’re choosing a skincare product, you need to do the same when you’re shopping around for an SPF too.
SPF for oily skin
A lightweight moisturiser that contains SPF, but won’t block your pores may be the best option for you.
Quite a few sunscreens that have a high SPF factor tend to have a thicker consistency, and this heavier consistency can leave your skin feeling clogged and sticky.
This is far from ideal, especially if your skin is already quite greasy - your pores are already prone to getting clogged and developing blemishes.6
Look out for: Oil-free, lightweight creams, gels, fluids, lotions and mineral powders that won’t leave your skin feeling greasy or congested.
SPF for sensitive, blemish-prone skin
SPFs that don’t contain certain ingredients, particularly benzophenones, that can irritate skin get on better with sensitive and blemish-prone skin.
Alcohols aren’t ideal either because they can aggravate and dry skin out. If your skin is extremely sensitive, try a mineral powder sunscreen instead. They dust on to your skin and feel weightless.7
Look out for: Lightweight or mineral powder sunscreens that contain minimal ingredients and no additional preservatives or fragrances that can aggravate skin.
SPF for dry skin
Choose lightweight SPFs that also act as a moisturising face cream or serum. They deliver a double action boost by hydrating skin as well as protecting it from the sun.
Cream or lotion-based SPFs tend to have the best staying power too.8
Look out for: SPF serums that are packed full of moisture and don’t overwhelm skin.
SPF for combination skin
Stick to a lightweight SPF that will provide protection without flooding your skin with too much heavy product and block your pores, while also providing moisture where it’s needed too.
Look out for: SPF gel formulations that aren’t too thick or greasy, but will still provide adequate moisture.
SPF for your eyes and lips
Just as there are moisturisers with SPF and face cream with SPF, there are specific sunscreen products for protecting the skin around your eyes, your lips and your hands from the sun too.
Look out for lip balm with SPF, eye cream with SPF and hand cream with SPF that have been specially formulated to protect while also taking care of your lips, delicate eye area and hands.
Oh, and don’t forget, you can also get foundation with SPF too, but some of the SPF ratings can be on the lower side, so you may need to use them alongside an additional sunscreen product to bump up your level of protection.
Which SPF is best?
A four-star UVA protection and SPF 15 is recommended for most people as a shield against the sun’s rays. However, this can differ depending on your skin type.
For a boost of added moisture, those with dry skin should opt for cream or gel-based products.
If you have oily or spot-prone skin, oil-free sunscreens will protect you from the sun without clogging your pores.
Mineral, oil-free, fragrance-free and hypoallergenic products are ideal for sensitive skin as they contain fewer chemicals.
- Choose an SPF based on your skin type
- Lightweight SPFs are better for oily or combination skin. Moisturising SPFs are better for dry skin
- A 4-star UVA protection and SPF 15 is recommended for most people
Do you need to wear sunscreen in the winter?
Though it may be cold outside and summer is long gone, you’re still at risk of burning, even on cloudy days.
In winter, reflected light from snow, sand and water can also intensify your exposure to UV rays.
Unless you’re a spending a long time out in the winter sun, an SPF or SPF-containing moisturiser will help protect you against short periods of UV exposure.
Sunscreen is best saved for extended UV exposure, which includes spending an hour or more outside.
Does wearing SPF all year lead to Vitamin D deficiency?
Vitamin D is created by our bodies from direct sunlight on our skin when we’re outside.
From October to March, sunlight doesn’t contain enough UVB for our bodies to absorb Vitamin D.
However, sun safety is still important so make sure to protect your skin whenever it’s exposed to the sun.
Eating oily fish, eggs or using a supplement are alternative sources of Vitamin D.
- You can still get sunburnt, even on cloudy days
- SPFs shouldn’t just be worn during the summer
- Sun safety is still important, as well as Vitamin D absorption
A final few words about SPF…
Just as you may not be able to live without your favourite stay-put lippie or double length mascara, the same principle applies to SPF too – it’s a skincare staple for your face and body that should never be overlooked.
The great thing is, there are so many different sunscreens available.
Not only are they suitable for all types of skin, but they’re available in a form that works best for your skin, e.g. gel, mineral or serum, foundation or moisturiser.
If it isn’t already in there, add SPF into your daily skincare regime, and if it is, great news, keep applying it every day.
Last updated: 17 June 2021