Crossing the future of sunscreen regulation: an overview of the New ISO Standards by Mérieux

31 October 2024

As the global cosmetics industry continues to evolve, regulatory bodies are increasingly focusing on the safety and efficacy of sunscreen products. In response to this growing emphasis, the International Organization for Standardization (ISO) is set to introduce two pivotal standards: ISO 23675 and ISO 23698. These standards, expected to be published by the end of 2024, represent a significant advancement in the way sunscreen efficacy is measured, moving towards more reliable and ethical testing methodologies.

Understanding the need for New ISO Standards

The development of ISO 23675 and ISO 23698 reflects a decade-long effort to enhance the accuracy and reliability of sunscreen testing. Current standards, such as ISO 24444 (in vivo SPF testing) and ISO 24443 (in vitro UVA protection), have provided a robust framework for evaluating sunscreen products. However, they are not without limitations, particularly concerning ethical concerns associated with in vivo testing on volunteers and the variability in results due to environmental factors.

The new standards aim to address these issues by introducing alternative methods that emphasize non-invasive testing and greater consistency in results. This shift aligns with the European Union’s regulatory framework, which has long advocated for testing methods that reduce the need for using human volunteers wherever possible.

ISO 23675: In Vitro Determination of Sun Protection Factor (SPF)

ISO 23675 introduces a new in vitro method for determining the SPF of sunscreen products, focusing on spectrophotometric analysis to measure UV radiation (UVR) transmission. This method is designed specifically for sunscreen formulations such as water emulsions or hydroalcoholic one-phase products, excluding powders and stick forms.

One of the key advantages of ISO 23675 is its non-invasive nature, eliminating the ethical concerns tied to in vivo testing. Additionally, it offers higher repeatability and lower variability, making it a faster and more cost-effective alternative. However, it also presents challenges, such as the need for precise calibration and the inability to measure water resistance, which remains a critical factor for many users.

ISO 23698: Hybrid Diffuse Reflectance Spectroscopy (HDSR)

Complementing ISO 23675, ISO 23698 introduces Hybrid Diffuse Reflectance Spectroscopy (HDSR), a method that combines in vitro and in vivo approaches to assess sunscreen efficacy. HDSR evaluates the effectiveness of sunscreen products in blocking UV radiation by measuring the remitted light from the skin, offering detailed information on both UVB and UVA protection without the need for invasive procedures.

The HDSR method is particularly suitable for rapid screening of sunscreen formulations, providing detailed protection metrics that can be crucial for product development and marketing. However, like the in vitro method, it does not account for water resistance.

Preparing for the future

As we await the final vote and publication of these new standards, set for late 2024, it is crucial for cosmetic companies in the sunscreen industry to begin aware for this new evaluating opportunity. The new ISO standards may represent a forward-looking approach to sunscreen regulation, prioritizing both end user safety and ethical considerations in testing. By embracing these changes, companies can not only ensure compliance with future regulations but also lead the way in the development of more effective and responsible sunscreen products.