We've rounded up the common sunscreen mistakes people make, as well as popular misconceptions that can contribute to getting caught out – and how to avoid them.
1. Not using enough sunscreen - and not reapplying frequently
Most people don't apply enough sunscreen to achieve the SPF specified on the packaging, the World Health Organization (WHO) says.
The WHO recommends around one teaspoon-sized dollop of sun cream per limb/body part, so that's seven teaspoons if you're doing your whole body.
Sunscreen needs to be re-applied regularly, especially after swimming and other sporting activities where water, friction or sweat can impact protection levels.
Don't assume clouds mean you don't need sunscreen, either: you can still burn even on cloudier days.
2. Dismissing cheap sun cream
But our tests have shown that you don't need to spend a lot to get good sun cream. We've tried supermarket and discount store brands alongside the big brands and found plenty that pass key sun protection tests.
Not all budget (or premium) options offer good protection, though. Nearly every year, we uncover sun creams that fail to pass our tests, which are based on the international test standard for sunscreen.
3. Relying too much on once-a-day or water-resistant claims (without reading the small print)
Claims on once-a-day or water-resistant products are often based on very specific test criteria (found in small print on the back of the bottle).
But based on our previous research, we're concerned that they don't stand up to real-world conditions.
When we tested once-a-day sunscreens in 2016, we found that the SPF provided fell by 74% after six to eight hours of wear.
Our tests also found that salt water, chlorinated water and fast-running water made water-resistant sunscreens less effective.
So, even if you opt for one of these products, don't skimp on the reapplying, especially after vigorous activity – and read the caveats.
we reveal the tastiest bangers for your BBQ4. Using old or out-of-date sunscreen
Sun cream usually lasts for one to two years after opening. Beyond this, it may not protect you as expected because the active ingredients can degrade, so it's best not to rely on an old bottle you've dug out of the cupboard.
To find the expiry date, look for an illustration of a circular pot with an open lid on the back of the bottle. This tells you how many months you can use it for after it's been opened (see picture above). So 12M means it's OK for 12 months after opening, 24M means 24 months.
Don't leave your sun cream lying around in the sun, as heat and light can also degrade it.
Store in a cool, dark place. When you're by the pool or at the beach, pop it in a cool bag or cover it with your other belongings to protect it.
5. Not putting on sunscreen until you're already outside
While it's not always possible to predict when you'll need it, sunscreen should ideally be applied 20-30 minutes before sun exposure (and before insect repellent, moisturiser and make-up).
This is especially the case for chemical-based sunscreens – the most common high street type.
These work by absorbing UV rays, and need to sink into the skin for optimal protection.
However, it's worth also applying mineral sun blocks in advance. These sit on top of the skin and reflect light away.
– keep mosquitos, ticks and other biting insects at bay for less6. Misunderstanding how SPF numbers work
The SPF (sun protection factor) is an indication of the proportion of UVB rays that a product filters out. Those with higher SPFs filter out more than lower ones.
But it's best not to think of the SPF number as indicating how much longer you can stay out in the sun without burning, as it isn't quite that simple.
SPF numbers aren't a linear scale. For example, SPF 30 filters out around 97% of UVB rays, SPF 50 around 98% and SPF 100 about 99%. So don't let an ultra-high SPF lull you into a false sense of security. Frequent reapplication is still important, especially if you have very sun-sensitive skin.
– find out more in our sun cream buying guide7. Missing common sunburn hotspots
It's all too easy to 'miss a bit', so pay particular attention to areas that are highly exposed, prone to sweating or friction from clothing or towel-drying, plus skin that doesn't get much sun exposure. These include the following:
8. Relying solely on sun cream
The British Association of Dermatologists (BAD) warns that no sunscreen will provide 100% protection and it shouldn't be used instead of covering up with clothing and staying in the shade – so don't use it as an excuse to expose yourself to the sun for longer.
Protect your skin with clothing and wear broad-brimmed or bucket-style hats that covers delicate areas including the neck and ears.
The sun is highest in the sky and at its strongest in the middle of the day, so, where possible, stay try to stay in the shade between 11am and 3pm.
– our expert garden furniture buying guide reveals outdoor furniture options, how to care for them and which shops to buy from9. Not realising that some medicines make you sun sensitive
It's worth knowing that some common medications can make your skin more sensitive to the sun.
Professor Claire Anderson, president of the Royal Pharmaceutical Society, says: 'Quite a few medicines can make you more photosensitive, including common drugs such as antibiotics, oral contraceptives and antidepressants – but not everyone who takes them will have a reaction.'
It's worth checking the small print for any new medicines, and if you notice an unusual reaction from sun exposure and have started a new medication recently, talk to your pharmacist.
Reduce your risk of side effects such as a rash or sunburn-like symptoms by staying out of direct sunlight, using a high-factor sun cream and covering up with long sleeves, trousers and a hat.
A sun cream designed for sensitive skin may also help to reduce the risk of a reaction.
Medications that can cause sun sensitivity
amiodaronetrimethoprim doxycycline amitriptyline clomipraminesulphonylureaisotretinoinCoal tar preparationssteroid creams furosemidethiazideAntimalarial drugs – what you eat or drink can affect how well your medication works, and can even be dangerous10. Using SPF make-up in place of sun cream
Even if your make-up is claimed to offer sun protection, you’d typically need to apply several times the normal amount of it to get even close to the level of protection stated on the packaging.
Not only that, but you're less likely to reapply make-up regularly enough, which means that using make-up with SPF is not a substitute for using sunscreen.
Professor Brian Diffey, emeritus professor of photobiology at Newcastle University, says: 'Apply sunscreen first as it needs to bind to the outer layer of the skin to be effective.'
If you put make-up on first, the sunscreen might not bind properly, which could compromise its ability to protect you.
How to buy the best and use it safely11. Thinking that having darker skin protects you
Those with darker skin tones may not get obvious colour changes with sunburn – it might manifest itself in the form of sore, itchy and tender skin instead.
Misconceptions about the protective effects of having a tan still abound, too. The bottom line is that sun protection is important for everyone.
– see our guide to the 'sunshine vitamin'How to stay safe in the sun
Use a sun cream you can rely on.Don't neglect your eyes. Know that UVA rays can penetrate through glass. – see how users rated high street opticians for eye tests and buying glasses or contactssource https://www.which.co.uk/news/article/11-common-sunscreen-mistakes-to-avoid-a4KPt2L7WDYd