DIN 53240-1:2013-06

The standard specifies a method for determination of the hydroxyl value of resins, oils, solvents and other organic substances for technical applications. The method provided corresponds in essence with the method contained in the 1968 Deutsche Arzneibuch (German Pharmacopoeia), Edition 7 and, consequently, those published by the "Deutschen Gesellschaft für Fettwissenschaft e. V." ("German Society for Fat Science") under C V 17 a (1953). However, the scope has been extended to include substances with very low and very high hydroxyl values. Moreover, the method has been formulated such that variations in the interest of a higher degree of precision (for instance potentiometric titration) can be made without having to work outside the standard. If no consistent results are obtained in individual cases by the described method, special acetylation conditions shall be agreed and provided in the test report. For hydroxyl values below 1 work shall be carried out very precisely in order to comply with the indicated error margins; furthermore, the error margins are substance-dependent. NA 002-00-02 AA "Lackrohstoffe" ("Raw materials for paints and varnishes") is responsible for this standard at DIN.