According to consumer organisation Which?, two of the UK's most popular sunscreen lotion brands do not give as much sun protection as they claim.
It is advised that consumers do not buy the products labelled sun protection factor (SPF) 30. One of them is made by Boots and the other is sold under the Hawaiian Tropic brand, however both companies have rejected the claims, saying their sunscreens are fully effective.
Which? said that Soltan Protect and Moisturise Lotion (SP30) and Hawaiian Tropic Silk Hydration Lotion (SP30) obtain only two-thirds of the skin protection they should.
The SPF figure is designed to measure the amount of protection against harmful ultraviolet B (UVB) rays from the sun, which is the main cause of sunburn. Both products passed the tests for ultraviolet A (UVA) rays, which are less dangerous, but more prevalent.
Both product makers have denied the claims.
Hawaiian Tropic said all their sun tan lotions are rigorously tested, "meeting all SPF, UVA and EU requirements and regulations". Additionally, they said their own tests suggested that the Silk Hydration and Satin Protection lotions "exceed the label claims, even after 80 minutes in water".
Boots said they are confident that all their sun care products meet the SPF labelling claims. "Customers can rely on them to provide the level of protection expected," said a Boots spokesperson.