NBN EN 646:2006

This document describes procedures for the testing of dyed paper and board intended to come into contact with foodstuffs. Two procedures are given. Procedure A for contact of long duration (e. g. food packaging) and procedure B for contact of short duration (e. g. napkins, kitchen papers, household papers).
Visual evaluation against a blank is used only in order to detect any bleeding (yes/no) while evaluation against a grey scale provides grading of the bleeding.