How to choose a sunscreen: SPF for face and body explained

When warm, sunny weather arrives we are glad to shed layers and enjoy it. Sun helps the body make vitamin D and lifts the mood. Too much of it ages skin, burns it and raises the risk of skin cancer, melanoma included. That makes sun protection part of everyday skin care rather than a beach accessory.

UVA and UVB: what sunscreen protects against

Sunlight contains three kinds of ultraviolet rays: UVA (reach deep into the skin and speed up ageing), UVB (cause sunburn and tanning) and UVC (the most dangerous, almost entirely blocked by the atmosphere). Both UVA and UVB raise the risk of skin cancer.

SPF tells you about UVB only, that is, about burning. UVA protection is labelled differently depending on where you buy:

Market	UVA label
European Union	"UVA" in a circle: UVA protection is at least one third of the SPF
United Kingdom	The same circle, often with a star rating of up to five stars
United States	"Broad spectrum" on the label
Asia	PA with plus signs; PA++++ is the highest

A sunscreen without any of these protects against burning, but not against skin ageing.

SPF 15, 30 or 50: what the number means

SPF	UVB filtered	EU category	Suited to
6–10	up to 90%	Low	Not enough for daily protection
15–25	about 93–96%	Medium	Short time outdoors in autumn and winter
30–50	about 97–98%	High	Daily use and holidays
50+	over 98%	Very high	Fair and sensitive skin, children, mountains, by the water

Dermatologists recommend at least SPF 30 for every day. Go higher for children, for very fair or sensitive skin and for anyone with many moles. No sunscreen blocks 100% of the rays.

The biggest myth: SPF extends your time in the sun

An old formula still circulates: if fair skin burns after five minutes without protection and the SPF is 10, you can stay out for 50 minutes. It is wrong, and no dermatology body recommends it.

The reasons are simple. SPF is measured in a laboratory with a thick layer of product that almost nobody applies in real life. Towels, clothes, sweat and water rub sunscreen off. And UVA affects skin even when it does not redden. So there is one rule: put sunscreen on every day you will be outdoors and reapply every two hours, whatever the SPF.

The same goes for products labelled "all-day protection" or "water resistant": swimming, sweating and friction weaken protection, so reapply after the water.

How much sunscreen to apply, and when

1. Amount. About 36 grams, six teaspoons or one ounce, for an adult body. For face and neck, about half a teaspoon, or two finger-lengths of product. Half the amount gives several times less protection.
2. Timing. Apply 15 to 30 minutes before going out.
3. Reapplying. Every two hours, and after swimming, sweating or towelling.
4. Forgotten places. Ears, the back of the neck, the parting, the tops of the feet, hands, lips.
5. Shelf life. An opened sunscreen is usually good for 12 months ("12M" on the pack). One that has overheated in a car protects less.

Face and lips need stronger protection. A lip balm with SPF is a must in summer.

Sunscreen for the face

• Oily and combination skin: light fluids and gels marked non-comedogenic.
• Dry skin: creams with moisturising ingredients.
• Sensitive skin: mineral filters (zinc oxide, titanium dioxide) and fragrance-free formulas are often tolerated better.
• Under make-up: sunscreen goes on last in your skin care, before foundation. Foundation with SPF does not replace it, because we apply too little.
• During the day: an SPF spray or powder over make-up is handy for topping up, but it is an extra, not the main protection.

For the body, drier skin does better with a cream or lotion and oilier skin with a spray. Sprays are also easier on hairy skin. Spray generously and rub it in: a mist is not enough.

Children, sensitive skin and moles

Babies under six months should be kept out of direct sun; shade and clothing protect them. For older children choose SPF 50+ with UVA protection made for children and apply it generously. The same advice holds for very fair skin, redheads, people with many moles and those with skin cancer in the family.

If your skin is very sensitive, cover up: a wide-brimmed hat, sunglasses and light long-sleeved clothes protect more reliably than any cream.

Will you still tan with sunscreen?

Many people skip sunscreen because they believe it stops a tan. No sunscreen blocks every ray, so skin does tan with SPF 30, only more slowly and without burning. It is also worth knowing that there is no such thing as a healthy tan: a tan is the skin's response to damage. For a bronze shade, self-tanner is the safer route.

And vitamin D? Studies show that everyday sunscreen use does not cause vitamin D deficiency: a short time outdoors in summer is enough, and in northern winters we rely on food and supplements anyway.

If you burn

Get out of the sun, cool the skin with a cool shower or compress, drink more water and apply a moisturising lotion. Do not burst blisters. See a doctor if a large area is burnt, blisters appear, you have a fever, or a small child is burnt.

How models protect themselves

For models, even skin tone is a working tool: swimsuit lines or a burnt nose can cost a shoot. So agencies ask for one thing: SPF every day and no sunbathing before jobs. If a client wants tanned skin, a make-up artist creates it.

We talk about skin care before castings in model training. If you are not sure which routine suits your skin, book an image consultation. What to wear in today's weather is on the what to wear page, and for the rest of your routine see how to choose a face mask.

Frequently asked questions

SPF 30 or SPF 50: which should you choose?

SPF 30 is enough for every day if you apply enough and reapply. Choose SPF 50 or 50+ for fair and sensitive skin, children, seaside holidays and the mountains.

Do you need sunscreen on a cloudy day?

Yes. Much of the ultraviolet light passes through cloud. Go by the UV index: at 3 or above you need protection.

How much sunscreen does the face need?

About half a teaspoon for face and neck, or two finger-lengths of product.

Is foundation with SPF enough?

No. To reach the protection on the label you would need several times more foundation than anyone wears. Use a separate sunscreen underneath.

Can you use last year's sunscreen?

If it was opened more than 12 months ago, has changed smell, colour or texture, or was kept in the heat, buy a new one.

From what age can children use sunscreen?

Keep babies under six months in the shade and covered. Older children can use a children's SPF 50+ with UVA protection.