These test papers allow quick and easy detection of hydrogen sulphide. This gas occurs in the processing of raw oil. It is toxic even in low concentrations. Therefore, critical points are carefully checked. Sulphide containing solutions also give a positive reaction.

• Colour changes: White to brown-black

Lead acetate is toxic and the test paper needs to be declared as hazardous. The technically equivalent Sulphide test paper is a non-toxic and safe alternative.