SPF Guide: the science behind suncream
Do you really know the meaning of SPF? Here’s our genius guide on everything you ever wanted to know about your sun cream but were too busy to ask…
SPF stands for 'sun protection factor,' and it measures your sunscreen protection from the sun’s rays. Think of it as UVA(ging) and UVB(urning). There are also different formulations:
Mineral: A mineral sunscreen uses active mineral ingredients, such as zinc oxide and titanium oxide. They work by reflecting the sun's rays like a mirror to protect exposed skin.
Physical: Physical sunscreens are formulated with active mineral ingredients, such as titanium dioxide or zinc oxide and work by sitting on top of the skin to deflect and scatter damaging UV rays away from the surface.
Chemical: Chemical sunscreens are absorbed into the skin, which then absorbs UV rays. They work by converting the sun’s rays into heat and releasing them from the body. The active ingredients in chemical sunscreens can include avobenzone, octinoxate and oxybenzone.
What do the dermatologists recommend?
Broad spectrum is a must, water-resistant and SPF30 or above.
Is SPF 50 better than 30?
Between an SPF 30 and SPF 50, there is only a small difference in the increase of protection.
SPF 30 blocks nearly 97% of UVB radiation
SPF 50 blocks approximately 98% of UVB rays
Studies have shown we tend to re-apply less when opting for a higher factor, so whatever number you choose you must re-apply at least every two hours and after swimming and sweating.
What does ‘Reef Safe’ mean?
Some sunscreen manufacturers don’t include oxybenzone or octinoxate, and label their sunscreen ‘reef safe’. However, oxybenzone and octinoxate aren’t the only culprits that may be damaging to marine life. Several other chemicals used in sunscreens that research suggests might be a threat to coral reefs. The best way to ensure your sunscreen is safe for both corals and oceans is to check it’s ‘Certified COSMOS Natural.’ COSMOS means that an independent Soil Association body has certified that the ingredients in the sunscreen are completely natural and that manufacturing practices are clean and respectful of human health and the environment. Incognito SPF 30 Second Skin Suncream has this specific certification.
How long can I swim with water-resistant creams?
The term ‘water resistant’ means that the SPF is working for up to 40 minutes while swimming or sweating, and this number is almost doubled if the packaging states ‘very water resistant’.
Does SPF expire?
Yes. Throw away after three years and also if the texture or smell has changed – or else you’ll be at risk from burning.
What is the best sunscreen for darker skin?
Opt for products that say ‘sheer’ or ‘invisible’ as these will be less chalky and ashy on darker skin tones.
Glossier Daily Sunscreen SPF30, £20
Super sheer, groundbreaking water-gel formula.
Dermalogica Prisma Protect SPF30 at Harvey Nichols, £58
Makes skin radiate and protects as it goes.
Click here Olay Luminous Whip SPF30, £23
A brilliant everyday hydrator, that’s light as air and with added luminosity and SPF30.
Dr. Sam’s Daily Sunscreen, £29
This is the best sunscreen for spotty skin. It contains 5% niacinamide to calm acne and inflammation and protects from sun damage too.
Click hereElemis Daily Defence ShieldSPF30, £46
A great, weightless lotion that protects against sun and city damage and works for both men and women.
Brush on Block, £25
This is a genius product as it mattifies your face and also can be used as a head protector, to disguise oily roots and protect the scalp too.
What is the best SPF for the body?
Easy-to-use formulas protect when you’re poolside or in the park
Esthederm Adaptasun Protective Body Lotion, £44.50
Protects DNA while boosting the natural pigmentation process.
Bioderma Spray SPF50, £25
A brilliant all-rounder in a super-sized bottle so you’re not afraid to apply liberally.
Clarins Sun Care Body Oil-in-Mist UVA/UVB 30, £22
A non-greasy, luxurious spray that protects head, hair and body.
Soleil Toujours Organic Sheer Sunscreen Mist SPF 50, £32
Reaches parts other SPFs don’t quite reach courtesy of the super-powered spray.
Shade All-natural Sunscreen, £9.95
Housed in a recyclable tin, this formula uses non-nano zinc oxide, which acts as a physical barrier to the sun, reflecting it from the skin's surface. This does mean the formula won’t feel as sophisticated, with some chalkiness, but it’s perfect if you’re sensitive to mainstream chemical SPF, and are cutting down on the plastics too.
Incognito Sunscreen & insect Repellent SPF30, £24
The 3-in-1 formula protects against insect attacks, the sun and also ups your moisture levels too. Plus it comes in sugarcane plastic, which has a positive carbon footprint and is 100% recyclable.
Lastly, what SPF ingredients should you avoid?
Beware of oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate, which can bleach corals and some of these chemical filters are hormone disruptors.
With thanks to Howard Carter suncare expert, and CEO of Incognito.