The method of chemical analysis must be selected according to the purpose. Otherwise, proper results cannot be obtained. When analyzing PFOA as an example, the use of pretreatment methods intended for the textiles or leather for the analysis of resin films leads to lower results. Chemical analysis is used as one of the information to demonstrate that industrial products comply with substance restrictions. The information obtained from chemical analysis is important, but there are precautions. This paper describes the results of the chemical analysis of PFOA performed as a verification test and points to precaution regarding chemical analysis. The number of products published by the European Commission as pose a risk to environmental, which has increased approximate six-fold in the last decade. Certain substances contained in industrial products are restricted by legislation. Therefore, the manufacturers of industrial products need to be able to demonstrate that their products meet applicable substance restrictions. Restricted substances under REACH regulations and POPs regulations are often managed based on information provided by suppliers, but the concentration limits for certain PFAS restrictions are very low. Consequently, information from chemical analysis may be required to complementary the information provided by the suppliers.