The Cosmetic, Toiletry and Perfumery Association (CTPA), the organisation representing the cosmetics industry in the UK, has responded to a recent report on sunscreens published in British consumer-defence magazine Which?

Disappointingly Which? has chosen to raise a number of questions about water-resistant sunscreen safety which could alarm consumers - and even discourage them from using sunscreens as part of a sunsafe regime. Which? also offers outdated sun safety advice that could prove harmful to consumers,” states the CTPA.

The CTPA explains that these products are water-resistant, not waterproof, but nevertheless offer a “much higher level of protection than the Which? test on two anonymous products suggests.

The aim of the validated test method used by suncare manufacturers is to determine that the sunscreen will not be completely washed off while being worn in the water. Interestingly, tap water is used in the test as it is a more harsh solvent than salt or chlorinated water. To pass the test, a product must retain at least 50% of the initial SPF value after immersion in water. In fact an SPF 30 product will stop approximately 96% of UV rays reaching the skin and after robust water resistance testing the product will still filter out at least 93% of the sun’s UV rays. Clearly not the dramatic reduction in efficacy that Which? implies. However, a non-water-resistant product could be washed off the skin completely meaning no protection from UV rays (until reapplication),” said Dr Chris Flower, Chartered Biologist and toxicologist and Director-General of CTPA.

According to CTPA, water-resistant sunscreens (which may be labelled as water resistant or very water resistant) have been developed to be less easily removed when worn in water.

CTPA adds it is important to follow the instructions and to re-apply sunscreens regularly and especially after swimming or towelling dry, even water-resistant products.

"Rather than relying on sunscreen for protection in the water, consider avoiding swimming between 11am-3pm when the UV index is at its highest, wearing a ’rash vest’ and shorts or using a ’sunsuit’ for kids together with a broad brimmed hat or legionnaire style hat for kids when possible. Although some sunscreens claim to be water resistant, it’s important to remember that this doesn’t mean they are waterproof. Swimming and towel drying can remove the sunscreen, in addition to it rubbing off over time," added Dr Rachel Abbott, Consultant Dermatologist and British Skin Foundation spokesperson.

CTPA is also extremely concerned to see that Which? is telling its readers that if they burn in 10 minutes in the sun, using an SPF 30 sunscreen would allow them to stay in the sun for 300 minutes. “This is contrary to all the advice given by experts on sun protection,” said CTPA who recently wrote to Which? to emphasise this.