Calypso Once A Day Tan & Protect SPF25 - 200 ml CALC25TAN

Product Information

We tested two popular sun creams in chlorinated water (to mimic a swimming pool) and salty water (to emulate the sea). We also added another scenario using fast-moving tap water to see what effect this had. Most of the time, the products weren't as effective in our more realistic conditions as they were in tap water. Calypso Once A Day may cause staining on certain fabrics and surfaces. Always cover seats and cushions. May discolour nail products. 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

You can buy sun cream in pharmacies, supermarkets and discount stores, with some of our tested options coming from Asda, Boots, Garnier, Nivea and Wilko. Sun cream provides protection from sunlight using UV filters. These are classified into two types: chemical and physical – also known as mineral sun cream.Remember, sun cream is just one part of staying safe in the sun and it's also really important to encourage kids (and adults) to:

Avoid sun exposure between 11am - 3pm. Seek shade and always protect children with a hat, loose clothing and high SPF protection. When choosing sun cream for your child, look for a short ingredients list and the terms 'fragrance free' and 'hypoallergenic'. The WHO recommends 35ml of sun cream (seven teaspoons' worth) to cover an adult, so use around a quarter to a half of this depending on the size of your child. 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.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. Consider the time of day – If you're spending time in the sun without wearing sun cream, you should only do so before 11am or after 3pm, as the middle of the day is when you're at the greatest risk of getting burnt. 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. We saw an average 74% decrease in SPF protection at the end of the tests. We shared our concerns with Cancer Research UK (CRUK) and the British Association of Dermatologists (BAD). Both advise against relying on any sun cream for extended periods in the sun. If you're using sun cream at the beach, apply plenty before swimming, and again when you leave the water. Reef-safe sun creams

For any product to provide the SPF it claims, you need to apply 2mg per square cm – which means around a teaspoonful of product for your face. And, just as with sun cream, it needs to be reapplied regularly. 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. From April to September, when the UV Index is generally higher. It takes 10 to 15 minutes of sun exposure each day for those with fair-to-olive skin to get enough vitamin D. Do not exceed exposure to the sun for longer than your skin type allows, taking into account the strength of the sun. 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

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.

Our Once a Day Tan and Protect combines UVA/UVB protection with melanin boosting ingredients to increase the underlying process of tanning within your skin, providing a more uniform and longer-lasting tan. The water resistant formula provides all day UVA/UVB protection and ensure a golden and natural tan, with 0% self-tanner. 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. 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 Physical/mineral products reflect visible light as well as UV, which can make the formulations opaque and leave a white residue on the skin. Some formulations use nanoparticles of titanium dioxide and zinc oxide – the minerals responsible for the residue. Nanoparticles are smaller, and as they scatter visible light – rather than reflect it – the sun creams are transparent. How to use sun creamThere’s a long list of ingredients that are used as chemical absorbers, so it’s easiest to simply look for products that are labelled ‘sensitive’ rather than search for specific ingredients. SPF make-up: does it really offer protection from the sun? It's common for sun creams to claim to be 'water resistant', but this doesn't mean that they're waterproof. Mineral sunscreens in particular often promote their environmental credentials, the most common being that they’re ‘reef-safe’ or 'ocean-friendly'. Apply to all exposed areas especially those that are prone to sun radiation e.g. face, nose, receding hairline, shoulders and feet. This tends to mean that two commonly used chemical UV filters linked to coral bleaching – oxybenzone and octinoxate – aren’t used.