The Testing Laboratory Directorate (TLD) is accredited to perform testing of lead, cadmium, mercury and chrome (VI) in paper and cardboard. These characteristics are determined in a water extract, obtained in accordance with BDS EN 645. The lead and cadmium content are determined using ICP-OES, and the mercury content – using AAS by the cold mercury vapor method, and the chrome (VI) content is determined using spectrophotometry, in accordance with a departmental method.