DIN EN ISO 9020-1998DIN EN ISO 9397-1997DIN EN ISO 11402-1998DIN EN ISO 11402-2004
This International Standard specifies three methods for determining the free-formaldehyde content in the following: a) Phenolic resins, by potentiometric titration in aqueous or organic solution (hydroxylamine hydrochloride procedure). The method is applicable to resins with free-formaldehyde contents up to and including 15 % by mass. For free-formaldehyde contents between 15 % by mass and 30 % by mass, it may be necessary to adjust the concentrations of the standard volumetric solutions used accordingly. b) Amino resins and furan resins (sulfite procedure). The method is applicable to resins resulting from the polycondensation of urea and melamine with formaldehyde and to furan resins resulting from the polycondensation of furfuryl alcohol with formaldehyde without further modification. c) Condensation resins (KCN procedure), including urea resins, furan resins, melamine resins and phenolic resins, as well as combinations and modifications of these resins.