ČSN EN 648 (500488)

Die Annotation des Normtextes ČSN EN 648 (500488):

This document describes procedures for the testing of the fastness of fluorescent whitened paper and board intended to come into contact with foodstuffs. Some procedures depending on the foreseeable use of the material are given.
Visual absence of the glass fibre paper´s fluorescence under UV light is evaluated.
For samples having significant different sides, a migration can occur from one glass fibre to the other and could lead to wrong interpretation of the fastness of one side. It is advisable to check these samples using large sampling procedure to prevent cross contamination of the glass fibre during the migration procedure. The procedure is described in Annex A. If lower limit of detection is required, this procedure can also be used