This International Standard specifies a test method for the determination of pentachlorophenol (PCP) in an aqueous extract of pulp, paper and board. Although it was developed for paper and board intended to come into contact with foodstuffs, it is applicable to all kinds of pulp, paper and board. The working range for acetylation is 0,05 mg/kg to 0,5 mg/kg. NOTE The upper limit of the working range could be increased if the aqueous extract is diluted.