This document specifies a method for the determination of free and released formaldehyde in leathers. This method@ based on high performance liquid chromatography (HPLC)@ is selective and not sensitive to coloured extracts and is intended to be used for precise quantification of formaldehyde. The formaldehyde content is taken to be the quantity of free-formaldehyde and formaldehyde extracted through hydrolysis contained in a water extract from the leather under standard conditions.