In chromogenic films, the remaining metallic silver must be removed by solution in a chemical called a bleach fix or "blix", which contains a mixture of ammonium thiosulfate and ferrous EDTA, a powerful chelating agent.
The remaining metallic silver must be removed by solution in a chemical called a bleach fix or "blix", which contains a mixture of ammonium thiosulfate and ferrous EDTA. This was in chromogenic films. EDTA is a powerful chelating agent.