Homebrew PCBs

In a message dated 11/11/2003 5:54:38 PM Central Standard Time, 
suri_list@yahoo.com writes:
after i 
have used it for etching a board how can i dispose it safely so that 
it doesnt hurt the environment or anybody else.
Harshit:  You should be able to use the same solution for MORE than one 
board, depending on how DEEP you cover the board with it (6-7 mm. is usually 
enough!), how warm the solution is, the "oz. thickness" of the copper you use, 
whether single- or double-sided, etc. 

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.

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.


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