This document specifies requirements and recommendations for the design and execution of an interlaboratory comparison for validation of new standardized analytical methods in the field of water analysis, e.g. the number of participating laboratories and time schedules. This document is based on ISO 5725-1 and ISO 5725-2. NOTE The scope of other standards in the field of interlaboratory comparison, such as ISO/IEC 17043[3] and ISO 13528[1], is proficiency testing of analytical laboratories and not interlaboratory comparison for the validation of analytical methods.