EVS-EN ISO 17226-2:2019

This document specifies a method for the determination of free and released formaldehyde in leathers. This method, based on colorimetric analysis, is not intended to be used for a 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.
This process is not absolutely selective for formaldehyde. Other compounds such as extracted dyes could interfere at 412 nm.