Challenges in testing for textile-based menstruation products: Towards reproducible and comparable evaluation methods

Textile-based menstruation products, such as reusable period underwear, have emerged as sustainable alternatives to conventional disposable menstrual hygiene products. Despite their growing market presence, the assessment of their functional performance remains challenging due to the lack of standardization. Differences in product design, multilayer material structures, test fluids, and evaluation procedures hinder meaningful comparison between products and limit the reliability of performance claims. This paper examines the current challenges associated with testing key performance characteristics of textile-based menstruation products, including absorbency capacity, absorption rate, fluid distribution, and rewet behavior. Existing testing approaches from the fields of hygiene products and textile engineering are reviewed and evaluated regarding their applicability to period underwear. Particular attention is given to the selection of test fluids, highlighting the limitations of water-based methods and the potential of menstrual fluid simulants (MFS) to better replicate the complex rheological properties of menstrual discharge under laboratory conditions. The study further discusses the current standardization landscape, including ongoing activities within ISO Technical Committee 338 on menstrual products. While international standardization efforts are progressing, specific national and European standards addressing period underwear remain limited. The development of robust, reproducible, and comparable testing procedures is therefore essential to support future standardization, facilitate product benchmarking, and strengthen consumer confidence in textile-based menstrual products. By identifying critical methodological challenges and proposing considerations for improved test design, this work contributes to the advancement of reliable performance evaluation methods for reusable menstrual hygiene products.