What's a strategy for environmentally sound disposal of Pt/Pd developer and clearing baths? I plan to use potassium oxalate for my developer and ferric oxalate for my sensitizer. I know that potassium oxalate has toxic effects. I was thinking of using hypo clearing agent for clearing. But as long as it clears for archival purposes without bleaching the image, I could use something else. Does mixing potassium oxalate with a given clearing bath offset the toxic effects of the dev? Is there some way to treat discarded dev and/or clearing bath that renders these discarded chemicals environmentally benign? Does it make sense to bring discarded chemistry to a neutral pH of 7 before disposal? Is there documentation that someone knows of that addresses these disposal related questions?