The SPF number is found on every suncream packaging on the market. SPF is such a huge part of skincare that the technology has made its way into makeup and daily skincare products. Express.co.uk spoke to London-based domestic, dermatologic surgeon and lecturer Dr Luca Russo to find out everything you need to know about SPF
What does SPF mean?
SPF stands for sun protection factor, and it is a measure of the amount of ultraviolet B radiation (UVB) protection.
The number on the suncream bottle indicates the length of time it would take for UV to burn your skin compared to no sun cream at all.
Of course, this depends on the cream being applied exactly as the bottle instructs.
It would take 20 minutes to burn in midday sun without suncream on.
If you apply factor 15 it will take four hours for you to turn red, which is 15 times as long.
The NHS site explains: “SPFs are rated on a scale of 2 to 50+ based on the level of protection they offer, with 50+ offering the strongest form of UVB protection.
“The star rating measures the amount of ultraviolet A radiation (UVA) protection.
“You should see a star rating of up to 5 stars on UK sunscreens. The higher the star rating, the better.
“The letters ‘UVA’ inside a circle is a European marking. This means the UVA protection is at least a third of the SPF value and meets EU recommendations.
“Sunscreens that offer both UVA and UVB protection are sometimes called broad spectrum.”
READ MORE- Sun cream: Should you wear sun cream indoors? What factor sun cream?
How often should you apply sunscreen
Most people don’t apply enough sunscreen, and they don’t apply it often enough.
The NHS site advises: “As a guide, adults should aim to apply around two teaspoons of sunscreen if you’re just covering your head, arms and neck.
“Adults should apply two tablespoons if you’re covering your entire body while wearing a swimming costume.
“If sunscreen is applied too thinly, the amount of protection it gives is reduced.
“If you’re worried you might not be applying enough SPF30, you could use a sunscreen with a higher SPF.
“If you plan to be out in the sun long enough to risk burning, sunscreen needs to be applied twice.
“You need to apply it 30 minutes before going out, and then again just before going out.”
It adds: “Sunscreen should be applied to all exposed skin, including the face, neck and ears, and head if you have thinning or no hair, but a wide-brimmed hat is better.
“Sunscreen needs to be reapplied liberally and frequently, and according to the manufacturer’s instructions.
“This includes applying it straight after you have been in water, even if it’s ‘water resistant’, and after towel drying, sweating or when it may have rubbed off.
“It’s also recommended to reapply sunscreen every 2 hours, as the sun can dry it off your skin.”