ISO 16365-3:2014 specifies a method for the determination of esters including ester thermoplastic polyurethanes (TPU) and ether TPU for quality control without the necessity of sophisticated instrumentation and avoids or minimizes long-term microbial testing for TPU materials. The method described is used to distinguish major TPU types and characterize TPU mixtures.

The method is applicable to all linear polyurethanes based on 4,4'-diphenylmethane diisocyanate (MDI) and is intended for instance to minimize long-term tests related to microbe resistance and hydrolysis.