In addition to not matching EU regulations for UV protection, the researchers involved in the report question whether daily application of certain UV filters could have unwanted affects on health.
Out of the 35 products tested, seven do not provide sufficient UVA protection to comply with current regulation and less than half provided continued protection without reapplication, claims the study led by Professor Laurence Coiffard at the University of Nantes, France.
Daily cosmetics products, such as foundations, moisturisers and anti-aging creams, often contain UV filters in an attempt to fight against photoaging.
However, Coiffard and his team question the value of incorporating UV filters into products that are not designed to be reapplied during the day and do not provide the level of protection required.
The researchers tested the SPF value, the UVA protection factor (used to calculate the UVA/UVB ratio) and the critical wavelength of 35 products including day creams, anti-aging formulations, tinted face creams and foundations, and self tanning lotions, which all claimed to have an SPF between 4 and 30.
In vitro tests illustrated that there was a big difference in products sold in pharmacies when compared with those purchased in perfume stores.
Pharmacy products included names such as Avène, Caudalie, Vichy and Roc and the products found in perfume stores were brands such as Chanel, Dior, and Estée Lauder and Shiseido.
Out of the perfumery products, most only provided sufficient UVB protection and the UVA/UVB ratio, which should be above 3 to fit with European regulation, was under 3 for more than half of the products.
All of the pharmacy-sourced products respected the current standards for UVA and UVB ratios, according to the report.
Unlike sunscreen products, reapplication of these daily formulations is not suggested, which makes photostabilty (their ability to retain protection even after long sun exposure) particularly important.
According to Coiffard and the team, only eight out of the 35 products were deemed to be photostable, retaining 90 per cent of their effectiveness (UVB and UVA) after two hours of exposure to a solar simulator.
The report also notes that the average consumer does not apply the amount of sunscreen products recommended by the manufacturer to get the advertised level of protection, and the disparity in doses is likely to be even more significant with the daily use cosmetic products tested.
Furthermore, for Coiffard there is a question mark over the wisdom of incorporating certain UV filters into daily cosmetics, particularly those that such as benzophenone-3, as he claims these can bring on allergic reactions and perhaps even endocrine disruptions.
“Looking at the clsimed SPF levels and those measured by our team the quantity of UV products added to the formulations is far from being negligible,” he told CosmeticsDesign.
In addition, allergic reactions in particular are not dose dependent, he added.
But the most important conclusion for Coiffard is that the majority of these products do not respect the current regulation in terms of UVA protection and photostability and consumers should be made aware of this.
Source: Archives Dermatological Research
DOI 10.1007/s00403-009-0974-2
Are cosmetic products which include an SPF appropriate for daily use?
Delphine Déhédic, Armelle Hardy-Biosmartel, Céline Couteau, Laurence J. M. Coiffard.