Disc stack separators are among the most complex hygienic process machines used in the food and pharmaceutical industries. Their unique operating conditions, including high centrifugal forces, dynamic seals, and intentional solids accumulation, create hygienic challenges that are not fully addressed by general hygienic design principles.

The second edition of EHEDG Guideline 42 provides practical guidance for the hygienic design, cleaning, and validation of disc stack centrifuges. Developed by the EHEDG Disk Stack Separators Working Group, it addresses key topics such as product-contact surfaces, drainage, seals, CIP cleaning strategies, and cleanability validation under realistic operating conditions.

The guideline highlights the importance of effective solids removal during production and cleaning and recommends validation methods such as design reviews, visual inspections, and riboflavin testing.

This presentation outlines the industry challenges that led to the development of Guideline 42 and summarizes the benefits it provides for both equipment manufacturers and end users seeking to improve hygienic performance, food safety, and cleaning reliability.