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about etching solution, is it safe to trow away normally? Answered

ive read alot about etching ur own PCB's and might start on it sooner or later, but i wanted to know, can u just trow away used solution down the drain.
i wondered about this since it eats away copper, and some pipelines are made out of copper...
and isnt it to chemical to trow away (like batteries and other electronics) normally...



Best Answer 8 years ago

Sewage pipes are made of plastic or clay, so will not be damaged by the etchant.

However, the dissolved chemicals are highly toxic to the environment, and probably not removed from the waste stream by most sewage treatments.

Whilst small amounts are probably OK to go down the drain (along with a lot of water), larger amounts need disposing of properly.  Unfortunately, through official channels, this is expensive.

If I were disposing of it, I would leave the mixture somewhere warm to dry out, then leave the encrusted container with the batteries at the local dump.

so with the small amounts coming from like that sponge+ferric chloride methode i  can just clean out the sponge using the drain? how much water would i roughly need for that?

and when do i need to dispose it trough official channels?

and that last thing, what happens to it when its in the air?

Sponge: I would say it's OK.  Rinse it in a full bucket, pour that down the toilet, then flush.

Officially, all chemicals must be disposed of through official channels (in the UK) - my school has numerous small bottles of useless chemicals (decomposed, dried out etc), but we can't throw them out because that would cost hundreds of pounds.

In the air?  Nothing that I know of - when it dries, the water evaporates, not the iron compounds.  Water vapour is harmless.

and it wouldnt cost anything to dispose those iron compounds when u trow it away with your batteries? nice!


It depends on your local rules - in the UK, some dumps charge to accept batteries and other unusual items, others don't.