Once-a-day suncreams may not offer long-lasting protection

Woman applies sunscreen on a toddler's face

Once-a-day suncreams fail to offer the long-term protection from harmful UVB rays claimed on the products, according to the results of a test carried out by the consumer watchdog Which?. On average, the sun protection factor (SPF) dropped by 74% after six to eight hours, it claims. 

Which? put four products to the test: Boots Soltan Once 8hr Sun Protection SPF30 (200ml); Piz Buin 1 Day Long Lotion SPF30 (150ml); Riemann P20 Once a Day Sun Protection SPF30 Spray (200ml); and UltraSun Family SPF30 (100ml). 

It tested the SPF factor of the products and then applied the creams to the backs of volunteers who wore T-shirts and were allowed to sit on a chair in a laboratory. After six to eight hours, the cream’s SPF was retested and had fallen by 74% on average. The reduction was most likely caused by the volunteers’ backs rubbing up against the T-shirt and chair, it says. 

“While our tests didn’t subject the suncreams to additional challenges (such as heat, sweat or water), we still saw substantial falls in the level of sun protection,” says Which?.

Which? now wants the UK to take a similar approach to Australia where once-a-day sun protection claims on products are banned on the grounds of lack of evidence, according to the Australian government’s Therapeutic Goods Association, the statutory medicines regulatory authority. 

The call is backed by the British Association of Dermatologists and Cancer Research UK. Both advise that suncream should be reapplied regularly throughout the day regardless of the claims that appear on the product’s label.

Last updated
The Pharmaceutical Journal, PJ, June 2016, Vol 296, No 7890;296(7890):DOI:10.1211/PJ.2016.20201226

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