The leaching tests were performed by dispersion of the perovskite powder in distilled water, under magnetic stirring for 4 h. Then the suspension was filtered on 0.2 µm nylon membrane and the amount of Ag and Bi in solution was determined by ICP-OES, after acidification (1% v/v ultrapure nitric acid). The Cs2AgBiCl6 perovskite resulted stable, with a leaching < 0.1 % for Ag and < 0.05 % for Bi. As silver could interfere by complexing ammonia, leaching tests were also performed on all the g-C3N4/Cs2AgBiCl6 composites, highlighting a negligible Ag release (< 0.9 %) also for the best performing material with negligible complex formation, further confirmed by ISE measurements, in NaOH/EDTA in place of NaOH solution.