Quote Originally Posted by Gerald C Koch View Post
Kodak D-25 developer was developed as a safer substitute for ppd developers. It is D-23 with the addition of 15.0 g/l of sodium bisulfite. It is said to produce fine grain comparable to that of the phenylenediamine developers with less chance of causing allergic dermatitis.
D-23 and D-25 were published at the same time, in fact Kodatol was Kodak's alternative to PDD super fine grain developers, they were all part of the same research project which included an early version of Microdol. Kodak chose to sell Kodatol DK-20 and then switched to Microdol and finally Microdol-X. There were issues with dichroic fog with Kodak films and D-25 and DK-20 and later Microdol. This got worse when Kodak improved their films in the 60's.

Ian