Formaldehyde in textiles

Cut the sample of textile into of 3 x 3 mm pieces (equal number of printed and unprinted sample) using scissors. Place 5 g together with exactly 100 ml water in a 200 ml Erlenmeyer flask with ground glass stoppers. Heat for 1 hour at 40 °C in a water bath, occasionally shaking. Allow to cool to 20 - 25 °C and filter off solid particles with a fluted filter.