Source: Cosmetics Europe

The International Organization for Standardization, ISO, has recently published the standard ISO 23675:2024 , In vitro determination of sun protection factor (SPF). The new test method is based on Cosmetics Europe's work with the Double Plate Method (DPM).

DPM is an in vitro test method for sun protection factor (SPF) and an alternative to the currently used standard method (ISO 24444:2019).

Now that the in vitro method is a recognized ISO standard method, manufacturers can test the effectiveness of sunscreen products with DPM both in Europe and in other regions of the world.

Advantages of the new in vitro method

• The method does not require human volunteers to test SPF, making it the only fully in vitro SPF ISO standard method
• The method provides consistent, reliable, repeatable and reproducible results that are consistent with those obtained with the current in vivo method.
• The method greatly reduces the risk of human error due to the use of state-of-the-art instrumentation, including a robot to spread the sunscreen product samples onto the plates and a spectrophotometer to measure their UVR (ultraviolet radiation) absorbance spectrum.
• The method can be used at any time of the year . The current standard method is based on testing the effect of a sunscreen product on the skin of volunteers, who must not be sunburned. This can be difficult to ensure in the summer. The DMP uses polymer plates to test the sunscreen product and can therefore be used all year round.

As a complete in vitro method, DPM also complies with the European Commission's 2006 “Sun Recommendation” on the efficacy of sunscreen products and claims made about them: the degree of protection against UVB and UVA should be measured using standardized, reproducible test methods, but preferably in vitro test methods if available.

The key characteristics of the method and its recognition as an international standard are a major scientific advance in the field of sun protection.

Cosmetics Europe will continue to work on developing test methods to establish different ways of measuring sun protection, and to raise awareness of the benefits of the method.