NBN ISO 14900:2021

This document specifies two methods for the measurement of the hydroxyl number of polyols used
as polyurethane raw materials. It is necessary to know the hydroxyl content of polyols to properly
formulate polyurethane systems. Method A is primarily applicable to readily esterified polyether
polyols. It is also intended for polyols which have significant steric hindrance, such as those based on
sugars. Method B is intended for polyether polyols, polymer polyols and amine-initiated polyols, but
may give low results for sterically hindered polyols. Other polyols can be analysed by these methods
if precautions are taken to verify applicability. These methods can be used for research and for quality
control and specification purposes.