Riemann P20 Once a Day Sun Protection SPF20 100ml

Product Information

We award Which? Best Buy status to products that we've independently reviewed that meet all our tough criteria: they must pass independent lab tests for UVA and UVB sun protection, and be easy and pleasant to apply. Even with our test subjects just sitting on a chair in a T-shirt, we saw substantial reductions in the level of sun protection, so we don't think you can rely on once-a-day sun cream to keep you protected all day. This is because, she said, the length of protection can vary depending on a person's activities - including how much they sweat and whether they towel dry, for example. Babies less than six months old should be kept out of direct sunlight, according to the NHS, and the skin of young children should be protected from the sun when UV levels are high. The regular reapplication advocated by most sunscreens protects us against this,’ he says. To apply sun cream properly you should:

However, there's no agreed definition of 'reef-safe', research is still ongoing as to the impact of these chemicals, and our tests found many mineral suncreams failed to protect as claimed – so take any claims with a pinch of salt. Kids' sun cream What's more, even if you follow all the rules, it's possible you won't get as much as protection as you expect. The industry guideline for water-resistant sun creams allows the SPF of a product to drop by 50% after a total of 40 minutes in water. Water-resistance testing also takes place in what is essentially a bath – using tap water.A spokesperson added: 'As with all sunscreens, it is important to follow the instructions for application and use; and sunscreen should not be used to intentionally stay longer in the sun. Sunscreen is just one part of a sun safe regime.' Boots Yes, you can - but you’ll also need to reapply frequently, just like you would if you were on the beach staying dry, and immediately after towel drying.

For more details on the importance of vitamin D and where to buy supplements, see our in-depth vitamin D guide . Other ways to stay safe in the sun They were allowed to wear t-shirts and sit on a chair (we did this because if you lie on a sun lounger or towel, get sandy, or wear a t-shirt on holiday it’s possible your single-use sunscreen could be rubbed off over time). Some people worry that using sun cream might prevent them from getting enough vitamin D, but this isn’t the case unless you really overdo it. We made multiple attempts to get in touch with Calypso, but the brand did not respond to any of our questions or send us a comment. RiemannA spokesperson told us that all of its sun creams are designed for 'longevity' but that it found the use of the word 'durable' more 'appropriate' than once a day.

Physical or mineral sun creams create a barrier on the skin that acts like a mirror, reflecting and scattering the UV light. We asked Boots a series of questions about its Once sun cream range and asked it to respond to our concerns about 'once a day' claims. Nobody applies sunscreen perfectly uniformly to all exposed skin and it is inevitable that we will miss patches of skin. It's clear that there are plenty of conditions to fulfil to get the claimed protection from once-a-day products, which may be hard to achieve if you're on a day out in the sun.Eat well, live better and stay healthy - sign up for our free monthly Food & Health newsletter for the latest insights delivered straight to your inbox Find out what you need to know about 'once a day' sun creams, water-resistant sun creams, sensitive sun screen and the best kids' sun cream too.