ISO 9397:1995

Cancels and replaces the first edition (1989). Lays down a method of chemically determining free formaldehyde in phenolic resins by potentiometric titration, in aqueous or organic solution. The method is applicable to resins with free-formaldehyde contents up to and including 15 % (m/m). For free-formaldehyde contents between 15 % (m/m) and 30 % (m/m), it may be necessary to adjust the concentrations of the standard volumetric solutions used accordingly. This method must not be used in the presence of hexamethylenetetramine.