Materials and surfaces are tested for air pollutants oxidation (NOx, acetaldehyde, etc) by applying the international standards “ISO 22197-1: Test Method for Air-purification Performance of Semiconducting Photocatalytic Materials - Part 1: Removal of Nitric Oxide” and “ISO 22197-2: Test method for air-purification performance of semiconducting photocatalytic materials - Part 2: Removal of acetaldehyde”. The equipment used for the measurement of the gas pollutants concentration are the NOx analyzer Horiba APNA-370 and the Tracera gas chromatograph 2010 SHIMADZU, respectively.