Gerald C Koch
Member
While neutral and basic solutions of potassium ferricyanide are relatively safe, the addition of acid can release hydrogen cyanide. Even relatively weak acids can do this. There is a case where a man committed suicide by adding a teaspoon of potassium ferricyanide to a glass of lemonade. Another point to remember is that cyanide ions pass readily through the skin. So avoid skin contact with acidified solutions such as the bleach mentioned in the post.
Since modern papers are quite different from the old Defender papers the toners mentioned may no longer be very useful. This is a common problem when trying to use old formulas with modern emulsions.
Since modern papers are quite different from the old Defender papers the toners mentioned may no longer be very useful. This is a common problem when trying to use old formulas with modern emulsions.