>
> I you use no more than a liter per month, you can probably flush small
> portions of that down the toilet, assuming you have "public sewer system". Sadly
> for me, I have "private" septic-tanks, so this would ruin the bacterialogical
> effect in that. SO, I pour the stuff on WEEDS in the yard, where there is no
> "good grass" to worry about. It is NOT horribly nasty, except on the fingers!
> However, I use no more than one or two liters of the stuff per year! Do you
> live near the sea? You can pour DOZENS of liters of it in the sea, and it will
> do NO harm, as it will be diluted in seconds, and will have NO "nasty"
> effects.
Just like it kills your microbes, it kills the ones at the local
water treatment plant and makes it harder for them to meet their waste
water standards. For that reason most places have an ordinance against
it, and if anyone did enough for them to track it down (easily traced
even long after btw) they're likely to get the fine to pay the city
employees for tracking it down. Might want to at least check what the
fine is first, some places have large fines for everything. That said a
bit now and then probably won't bring notice just don't do much this way
and dilute it heavily as you're doing it. Yard really wouldn't be a big
deal, and sea is actually a good idea the amounts would be miniscule.
>
> However, if you use 100 liters a week or more, I would not suggest this.
> BUT, ferric chloride is NOT used for large-quantity production of PCB's, now, is
> it??? Common sense!
>
> FeCl³ is simply IRON and CHLORINE. Chlorine is a "nasty" gas, but in ionic
> form, it combines readily with other ions to make harmless substances
> (table-salt is 50% chlorine!). Iron is not a poison! Now, if it were Arsenic
> Chloride, etc., that would be a different matter! Think about it.
But it's Copper Chloride by the time you pour it down the drain, not
Iron Chloride. And most if not all copper compounds are at least mildly
poisonous, CuCl is. FeCl is widely used to bind metals out of cow
manure for processing the waste as well as PC boards, not sure it's the
same type there are apparently two FeCl varieties. Once bound though
the results are usually mild hazards or worse, it has to do with the
bound metals not what it started as.
Still, recharge the stuff instead of throwing it away. It should be
cheaper to use nails and plate the copper back out than to buy new etchant.
Alan