Homebrew PCBs

John Michaud wrote:
> I didn't expect to generate so much attention to Ferric Chloride and with that living in Oregon I've been concerned with the environment so is there a environmentally safe method to etching?
> 

It will become environmentally unsafe if you decide to dump your *spent* 
etchant in a pond full of aquatic life.
Copper are the toxic atoms here, not the iron ions, chlorides, 
persulfates, peroxide. Copper is an essential nutrient in trace amounts 
so it ok if soil concentrations are not allowed to get too high. I 
forget what the figure is. You should precipitate the salts by adding 
lime before sprinkling it on your garden.

Adam