A fair point, but reading in depth, (and more than the agreeably out of context snippet I presented here) the article states higher levels than "those set by regulatory agencies", I'm sure those agencies have the health of humans as well as marine/plant life in mind, and anything that a "regulatory agency" does, has to be for the common good doesn't it.. :-) By the way have you ever tasted copper ? nasty stuff... (Must be why I only reached 'O' Level chemistry in high school) Jim ---------------------- www.jimfranklin.info PIC Micro Application website ----------------------------- -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Liam O'Hagan Sent: 02 March 2004 00:29 To: PICLIST@MITVMA.MIT.EDU Subject: Re: ] My first PCB production What is "contamination" though, 1ppm? 20ppm? I think it would go a lot further if you considered "contaminated" to be 1 atom per gallon, than if you considered contaminated to be 1 gram per litre for example > -----Original Message----- > From: Jim Franklin [SMTP:jim.franklin@BTCONNECT.COM] > Sent: Tuesday, March 02, 2004 11:20 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: ] My first PCB production > > I followed that link, > > "..Two pounds of root killer contain 0.5 pound of pure elemental copper > enough to contaminate 20 million gallons of water..." > > It makes you think, doesn't it when you see those kinds of numbers... > > Jim > > ----------------------------- > > -----Original Message----- > From: pic microcontroller discussion list > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of William Chops Westfield > Sent: 01 March 2004 23:15 > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: ] My first PCB production > > > On Monday, Mar 1, 2004, at 13:54 US/Pacific, Spehro Pefhany wrote: > > > > > But my wife, who is an expert in wastewater and other environmental > > technical and legal matters, thinks a bit down the home drain with lots > > of water isn't a technical problem. > > > > > Note that in the US, it is relatively common (or WAS relatively > common, anyway) to dump a couple pounds of copper sulfate down > your toilet to kill roots that might have been invading your > underground pipes. Or something. (Not that everyone is happy > with this: http://www.city.palo-alto.ca.us/cleanbay/pdf/root.pdf ) > > Copper sulfate is also pretty widely used as an agricultural > fungicide. > > If you get up to several ounces of copper per year (at 1oz per > square foot of typical PCB, so, serveral square feet of finished > PCBs), you should probably start thinking about being nicer than just > flushing your used etchant down the drain. But that's a awful LOT > of PCBs for the average hobbyist... > > BillW > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu