Ferric Oxalate Platinum printers use ferric oxalate as the light sensitive ingredient. It is an oxalic acid salt like the potassium oxalate developer, and as such it is also poisonous and like the developer, the body can deal with it in small quantities. The chelates Platinum printers use a variety of different compounds to help dissolve out the left over ferric oxalate. Since ferric oxalate is the first cousin to rust, we use many of the same compounds that are used to remove rust stains from pools and spas. EDTA is used agriculturally as an aid to help plants absorb iron from the soil.
Some printers use hydrochloric acid to help the ferric oxalate dissolve.
This is used in a very dilute solution and is relatively harmless in this concentration. Conclusion Platinum and palladium printing is in my opinion probably saver to the individual and environment than either the normal black and white silver or color photography. It uses no chlorinated hydrocarbons and the organic compounds that it uses are as stated above, the reasonably safe weak organic acid salts.