Homebrew PCBs

I design my own boards using positive acting pre-sensitized boards.

My developer solution is made of 1/2 teaspoon Sodium Hydroxide in 
300ml water.

My etch solution is made up of 1 part 31% Hydrochloric acid (HCl), 
and 2 parts 3% Hydrogen Peroxide (H2O2).

The above chemical solutions work very well for me, and are extremely 
fast. I'm not looking to find a better way. I am looking to reduce 
the waste that goes to the hazard waste facility.

I'm not a chemist, didn't even take high school chemistry. Anyway 
here is an experiment I did with the above chemicals, to try and 
reduce the amount of waste. 

Safety first, wear chemical goggles, gloves, apron, and work in a 
well ventilated area 

Hydrochloric acid (HCl) is very acidic, PH1. Sodium Hydroxide (NaOH) 
is very alkaline, PH14. When you mix an acid with an alkaline and 
adjust the solution to PH7 they become table salt and water.
HCl + NaOH = NaCl + H2O2

It takes a lot of Sodium Hydroxide to move from PH1 to PH2, but it 
takes very little to move from PH6 to PH7. And if the solution is 
very alkaline it takes a lot of Hydrochloric acid to move from PH14 
to PH13, and very little to move from PH8 to PH7.

I mixed the spent etchant and developer together and started to 
neutralize the mixture. At about PH6 what I believe to be copper 
chloride started to precipitate out of solution. After the solution 
had set for about 12 hours, a blue sludge had formed at the bottom of 
the container and what I believe to be saltwater solution was at the 
top. 

I siphoned off most of the water being careful not to disturb the 
sludge.

I tested the PH of the water that had been removed from the sludge 
container and it is still approximately PH7, and is crystal clear.

I have reduced the 3 liters of chemicals down to less than 250ml of 
sludge. 

Am I on the right track? 
Is the blue sludge copper hydroxide?
Can the sludge be reduced even more by drying?
If so how can it be safely dried? 
Is there an issue storing copper hydroxide in powder form?

----- Original Message ----- 

From: "pcb.easy" <rpdavidson@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, April 15, 2007 9:18 PM
Subject: [Homebrew_PCBs] Disposing of Chemicals


>I design my own boards using positive acting pre-sensitized boards.
>
> My developer solution is made of 1/2 teaspoon Sodium Hydroxide in
> 300ml water.
>
> My etch solution is made up of 1 part 31% Hydrochloric acid (HCl),
> and 2 parts 3% Hydrogen Peroxide (H2O2).
>
> The above chemical solutions work very well for me, and are extremely
> fast. I'm not looking to find a better way. I am looking to reduce
> the waste that goes to the hazard waste facility.
>
> I'm not a chemist, didn't even take high school chemistry. Anyway
> here is an experiment I did with the above chemicals, to try and
> reduce the amount of waste.
>
> Safety first, wear chemical goggles, gloves, apron, and work in a
> well ventilated area
>
> Hydrochloric acid (HCl) is very acidic, PH1. Sodium Hydroxide (NaOH)
> is very alkaline, PH14. When you mix an acid with an alkaline and
> adjust the solution to PH7 they become table salt and water.
> HCl + NaOH = NaCl + H2O2
>
> It takes a lot of Sodium Hydroxide to move from PH1 to PH2, but it
> takes very little to move from PH6 to PH7. And if the solution is
> very alkaline it takes a lot of Hydrochloric acid to move from PH14
> to PH13, and very little to move from PH8 to PH7.
>
> I mixed the spent etchant and developer together and started to
> neutralize the mixture. At about PH6 what I believe to be copper
> chloride started to precipitate out of solution. After the solution
> had set for about 12 hours, a blue sludge had formed at the bottom of
> the container and what I believe to be saltwater solution was at the
> top.
>
> I siphoned off most of the water being careful not to disturb the
> sludge.
>
> I tested the PH of the water that had been removed from the sludge
> container and it is still approximately PH7, and is crystal clear.
>
> I have reduced the 3 liters of chemicals down to less than 250ml of
> sludge.
>
> Am I on the right track?
> Is the blue sludge copper hydroxide?
> Can the sludge be reduced even more by drying?
> If so how can it be safely dried?
> Is there an issue storing copper hydroxide in powder form?

I think it's more likely to be cupric hydrate. You'll need to heat it to 
form the hydroxide.

Leon

I'm guessing, drawing on high school and college chemistry.

H2O2 + HCl + Cu -> 2H20 + CuCl
Unreacted H2O2 and HCl remain in solution.

HCl + NaOH -> NaCl + H2O

You are very unlikely to produce H2O2 in the reaction with HCl and NaOH, 
IMO.

My guess is that you have CuCl as the blue sludge.  I suppose it could 
be CuOH, but you'd have to convince yourself that Cu would rather bond 
with OH.  A smell of chlorine when you are reacting would be a clue, or 
bubbles and a yellow gas.

pcb.easy wrote:

> I design my own boards using positive acting pre-sensitized boards.
>
> My developer solution is made of 1/2 teaspoon Sodium Hydroxide in 
> 300ml water.
>
> My etch solution is made up of 1 part 31% Hydrochloric acid (HCl), 
> and 2 parts 3% Hydrogen Peroxide (H2O2).
>
> The above chemical solutions work very well for me, and are extremely 
> fast. I'm not looking to find a better way. I am looking to reduce 
> the waste that goes to the hazard waste facility.
>
> I'm not a chemist, didn't even take high school chemistry. Anyway 
> here is an experiment I did with the above chemicals, to try and 
> reduce the amount of waste. 
>
> Safety first, wear chemical goggles, gloves, apron, and work in a 
> well ventilated area 
>
> Hydrochloric acid (HCl) is very acidic, PH1. Sodium Hydroxide (NaOH) 
> is very alkaline, PH14. When you mix an acid with an alkaline and 
> adjust the solution to PH7 they become table salt and water.
> HCl + NaOH = NaCl + H2O2
>
> It takes a lot of Sodium Hydroxide to move from PH1 to PH2, but it 
> takes very little to move from PH6 to PH7. And if the solution is 
> very alkaline it takes a lot of Hydrochloric acid to move from PH14 
> to PH13, and very little to move from PH8 to PH7.
>
> I mixed the spent etchant and developer together and started to 
> neutralize the mixture. At about PH6 what I believe to be copper 
> chloride started to precipitate out of solution. After the solution 
> had set for about 12 hours, a blue sludge had formed at the bottom of 
> the container and what I believe to be saltwater solution was at the 
> top. 
>
> I siphoned off most of the water being careful not to disturb the 
> sludge.
>
> I tested the PH of the water that had been removed from the sludge 
> container and it is still approximately PH7, and is crystal clear.
>
> I have reduced the 3 liters of chemicals down to less than 250ml of 
> sludge. 
>
> Am I on the right track? 
> Is the blue sludge copper hydroxide?
> Can the sludge be reduced even more by drying?
> If so how can it be safely dried? 
> Is there an issue storing copper hydroxide in powder form?
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
>
>
>
>

--- In Homebrew_PCBs@yahoogroups.com, "Dale J. Chatham" <dale@...> 
wrote:
>
> I'm guessing, drawing on high school and college chemistry.
> 
> H2O2 + HCl + Cu -> 2H20 + CuCl
> Unreacted H2O2 and HCl remain in solution.
> 
> HCl + NaOH -> NaCl + H2O
> 
> You are very unlikely to produce H2O2 in the reaction with HCl and 
NaOH, 
> IMO.
> 
> My guess is that you have CuCl as the blue sludge.  I suppose it 
could 
> be CuOH, but you'd have to convince yourself that Cu would rather 
bond 
> with OH.  A smell of chlorine when you are reacting would be a 
clue, or 
> bubbles and a yellow gas.
> 
Thanks for your relpy. Your correct, I don't know why I typed HCl _ 
NaOH = NaCl + H2O2,  H2O2 is Hydrogen Peroxide. So the thinking is 
that the Blue sludge is CuCl, and the clear liquid at the top is salt 
water?

That is my thought.

I suppose the following could occur:
CuCl + NaOH -> CuOH + NaCl?

There has to be a way to predict it, but it's been a long, long time.


pcb.easy wrote:

> --- In Homebrew_PCBs@yahoogroups.com, "Dale J. Chatham" <dale@...> 
> wrote:
>   
>> I'm guessing, drawing on high school and college chemistry.
>>
>> H2O2 + HCl + Cu -> 2H20 + CuCl
>> Unreacted H2O2 and HCl remain in solution.
>>
>> HCl + NaOH -> NaCl + H2O
>>
>> You are very unlikely to produce H2O2 in the reaction with HCl and 
>>     
> NaOH, 
>   
>> IMO.
>>
>> My guess is that you have CuCl as the blue sludge.  I suppose it 
>>     
> could 
>   
>> be CuOH, but you'd have to convince yourself that Cu would rather 
>>     
> bond 
>   
>> with OH.  A smell of chlorine when you are reacting would be a 
>>     
> clue, or 
>   
>> bubbles and a yellow gas.
>>
>>     
> Thanks for your relpy. Your correct, I don't know why I typed HCl _ 
> NaOH = NaCl + H2O2,  H2O2 is Hydrogen Peroxide. So the thinking is 
> that the Blue sludge is CuCl, and the clear liquid at the top is salt 
> water?
>
>
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
>
>
>
>

Dale J. Chatham wrote:
> 
> 
> My guess is that you have CuCl as the blue sludge. I suppose it could
> be CuOH, but you'd have to convince yourself that Cu would rather bond
> with OH. A smell of chlorine when you are reacting would be a clue, or
> bubbles and a yellow gas.
> 

CuCl is copper(I) chloride, a white insoluble and unstable solid.

Or you have to convince yourself that sodium ion prefers chloride, 
therefore leaving copper ion nothing else but to except the hydroxide.

If the solid is a bright pale blue with clear liquid then you can be 
sure its copper hydroxide.

pcb.easy wrote:
> Am I on the right track?
> Can the sludge be reduced even more by drying?
> If so how can it be safely dried?

You are doing conventional heavy metal waste treatment by precipitation 
of metal hydroxides. For such small quantities you best off drying the 
sludge in a open tray and put the powder in a plastic or jar and then 
into the rubbish bin. This is more moral than dumping in the sewage 
system. I find builders lime (non pure calcium hydroxide) as a better 
etchant neutralizer as the resulting sludge is more solid and compact.

I have about 10kg of copper hydroxide accumulated of over the years :(

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...> 
wrote:
>
> Dale J. Chatham wrote:
> > 
> > 
> > My guess is that you have CuCl as the blue sludge. I suppose it 
could
> > be CuOH, but you'd have to convince yourself that Cu would rather 
bond
> > with OH. A smell of chlorine when you are reacting would be a 
clue, or
> > bubbles and a yellow gas.
> > 
> 
> CuCl is copper(I) chloride, a white insoluble and unstable solid.
> 
> Or you have to convince yourself that sodium ion prefers chloride, 
> therefore leaving copper ion nothing else but to except the 
hydroxide.
> 
> If the solid is a bright pale blue with clear liquid then you can 
be 
> sure its copper hydroxide.
>
Adam, 
The sludge is a bright pale blue, and the liquid is very clear. So 
you think it is copper hydroxide, Cu(OH)2.

Can I dry the copper hydroxide? How should it be stored?

My goal here is to reduce the volume of waste by extracting the 
water, and identify the substance to the hazard waste facility.

Thanks for you help.

Looks like I was wrong.  Dang, forgot more chemistry than most folks 
probably ever knew :)

Adam Seychell wrote:

> Dale J. Chatham wrote:
>   
>> My guess is that you have CuCl as the blue sludge. I suppose it could
>> be CuOH, but you'd have to convince yourself that Cu would rather bond
>> with OH. A smell of chlorine when you are reacting would be a clue, or
>> bubbles and a yellow gas.
>>
>>     
>
> CuCl is copper(I) chloride, a white insoluble and unstable solid.
>
> Or you have to convince yourself that sodium ion prefers chloride, 
> therefore leaving copper ion nothing else but to except the hydroxide.
>
> If the solid is a bright pale blue with clear liquid then you can be 
> sure its copper hydroxide.
>
>
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
>
>
>
>

pcb.easy wrote:
> Adam,

> Can I dry the copper hydroxide? How should it be stored?

Same as any chemical. In a clearly labeled container and away from 
children who likely to try eat it. Its a copper compound.
Label your chemicals for other peoples sake.

> My goal here is to reduce the volume of waste by extracting the
> water, and identify the substance to the hazard waste facility.

yes, your on track. One way is to have a small bucket or pail with a lid 
that you can periodically dump in sludge. Keep the bucket open and by 
time you ready to dump more sludge the previous lot will be dry.
You've already done the hard work of neutralizing, precipitating and 
removing the bulk of liquid (NaCl/NaOH solution).

Adam

by far the best way to dispose of chemicals 
  containing copper 
   
  is  to use cement  or lime  
   
  added as dust to use liquid
   
  stir let it go hard 
  then burn it ,,,,
   
   
   
   
  

Adam Seychell <a_seychell@...> wrote:
          pcb.easy wrote:
> Adam,

> Can I dry the copper hydroxide? How should it be stored?

Same as any chemical. In a clearly labeled container and away from 
children who likely to try eat it. Its a copper compound.
Label your chemicals for other peoples sake.

> My goal here is to reduce the volume of waste by extracting the
> water, and identify the substance to the hazard waste facility.

yes, your on track. One way is to have a small bucket or pail with a lid 
that you can periodically dump in sludge. Keep the bucket open and by 
time you ready to dump more sludge the previous lot will be dry.
You've already done the hard work of neutralizing, precipitating and 
removing the bulk of liquid (NaCl/NaOH solution).

Adam



         

       
---------------------------------
 Yahoo! Answers - Got a question? Someone out there knows the answer. Tryit now.

[Non-text portions of this message have been removed]

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...> 
wrote:
>
> pcb.easy wrote:
> > Adam,
> 
> > Can I dry the copper hydroxide? How should it be stored?
> 
> Same as any chemical. In a clearly labeled container and away from 
> children who likely to try eat it. Its a copper compound.
> Label your chemicals for other peoples sake.
> 
> > My goal here is to reduce the volume of waste by extracting the
> > water, and identify the substance to the hazard waste facility.
> 
> yes, your on track. One way is to have a small bucket or pail with 
a lid 
> that you can periodically dump in sludge. Keep the bucket open and 
by 
> time you ready to dump more sludge the previous lot will be dry.
> You've already done the hard work of neutralizing, precipitating 
and 
> removing the bulk of liquid (NaCl/NaOH solution).
> 
> Adam
>
Thanks for all your help. Sorry if my questions are elementary, I 
have no chemistry background. I like the etch, and speed of the HCl 
and H2O2 etchant, and now the fact that I can reduce the waste to 
almost nothing. One last question about the storage of dry copper 
hydroxide powder. Does it react to anything, such as moisture, light, 
plastics, metals?

Thanks for your help, and to everyone else, this group is great.

On Tue, 17 Apr 2007 00:43:19 +0200, simeon webber <vsmvdd@...>  
wrote:

>
>
>> Can I dry the copper hydroxide? How should it be stored?
> Same as any chemical. In a clearly labeled container and away from
> children who likely to try eat it. Its a copper compound.
> Label your chemicals for other peoples sake.
>
>> My goal here is to reduce the volume of waste by extracting the
>> water, and identify the substance to the hazard waste facility.
> yes, your on track. One way is to have a small bucket or pail with a lid
> that you can periodically dump in sludge. Keep the bucket open and by
> time you ready to dump more sludge the previous lot will be dry.
> You've already done the hard work of neutralizing, precipitating and
> removing the bulk of liquid (NaCl/NaOH solution).
> Adam


Could the copper salt not be collected and given away as new etchant?
I'm not sure it even needs neutralizing, CuCl dries to a green salt. Does  
adding Na. make it less useful for further use? Could the HCl be reduced  
by etching "until it stops"?

Remember the copper chloride "boiler cleaning sticks" we saw a while ago  
as possible source for CuCl? Maybe CuCl could be burned to achieve a  
similar effect with no harm done? What results when CuCl is burned?

ST

pcb.easy wrote:

One last question about the storage of dry copper
> hydroxide powder. Does it react to anything, such as moisture, light,
> plastics, metals?
> 


Its a hydroxide so it will react with acid to form a salt again. (e.g 
add vinegar to get copper acetate). I can't think of any plastic that 
wouldn't hold the sludge or power. Aluminum might not be a good idea, 
and steel will rust. Use any available plastic household container.

Stefan Trethan wrote:
> 
> Could the copper salt not be collected and given away as new etchant?
> I'm not sure it even needs neutralizing, CuCl dries to a green salt. Does  
> adding Na. make it less useful for further use? Could the HCl be reduced  
> by etching "until it stops"?

Evaporation will release the the free HCl and you should be left with 
hydrated CuCl2 crystals. I found it can take a while to dry.
The only purpose of neutralizing is for disposal. It never gets "used 
up", rather it slowly becomes a copper chloride etchant as opposed to 
pure HCl/H2O2 etchant. You still need to feed it HCl and H2O2 to keep it 
going, but HCl concentration doesn't become as important because the 
copper(II) ions are mostly doing the etching. H2O2 is like super 
effective aerating.

  What results when CuCl is burned?

For what happens when you heat CuCl2 see,
http://en.wikipedia.org/wiki/Copper(II)_chloride

At 08:41 07/04/18, Digest Number 2084 wrote:
>     Posted by: "Adam Seychell" a_seychell@... a_seychell
>     Date: Tue Apr 17, 2007 2:59 am ((PDT))
>
>pcb.easy wrote:
> >One last question about the storage of dry copper hydroxide powder.[snip]
>
>[snip] Use any available plastic household container.

No DONT!

Do not use anything which looks like a food container
(and especially a soft drink bottle) particularly if you
expect small children to be around and even if you don't ;-)

I can't see a good reason for keeping this waste product
as a trophy and there isn't likely to be a lot of it from amateur
processing, so unless you have serious intentions of
reclaiming the copper or re-using it in a CuCl etch system
I would recommend neutralizing your effluent with a small
excess of garden lime and immobilizing the precipitate
by the addition of a little cement. The resulting briquette
you should be able to throw into household waste with a
relatively clear conscience - otherwise it will store safely
until you can get it to a hazardous waste dump.


Regards, LenW
-- 
   From Yahoo! Groups help: ... trim all the irrelevant quoted text out of 
your message
   (as a courtesy to the other members of the group to make the digest 
easier to read).

Len Warner wrote:
> 

> Do not use anything which looks like a food container
> (and especially a soft drink bottle) particularly if you
> expect small children to be around and even if you don't ;-)

And thats why you label your containers, with poison signs.

> I would recommend neutralizing your effluent with a small
> excess of garden lime and immobilizing the precipitate
> by the addition of a little cement. ...

Yes, if end goal of the OP was to ditch the etchant, then I'd agree 
completely. "pcb.easy" seemed to be asking how to collect and store Cu(OH)2.

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...> 
wrote:
>
> Len Warner wrote:
> > 
> 
> > Do not use anything which looks like a food container
> > (and especially a soft drink bottle) particularly if you
> > expect small children to be around and even if you don't ;-)
> 
> And thats why you label your containers, with poison signs.
> 
> > I would recommend neutralizing your effluent with a small
> > excess of garden lime and immobilizing the precipitate
> > by the addition of a little cement. ...
> 
> Yes, if end goal of the OP was to ditch the etchant, then I'd agree 
> completely. "pcb.easy" seemed to be asking how to collect and store 
Cu(OH)2.
>
Gentlemen,

My goal is not to collect and store Cu(OH)2, but rather reduce the 
waste by removing the excess water. The reason for wanting to reduce 
the waste is so that I do not have a large volume of chemicals on 
hand, and do not have to make frequent trips to the hazard waste 
facility. I can not see how taking a small amount of copper hydroxide 
and contaminating a chunk of concrete and having it buried in a 
landfill is benifical. Have you seen how they crush and grind 
everything that goes into a landfill. Rather I would like to take it 
to a hazard waste facility and have it properly dealt with. If I was 
willing to have the copper dumped into a landfill and have it 
eventually work it way into the water supply, I might as well pour it 
down the drain. Once again thanks to everyone for the help.

On Wed, 18 Apr 2007 23:39:03 +0200, Adam Seychell  
<a_seychell@...> wrote:

>
> And thats why you label your containers, with poison signs.

NOT with poison signs.
If i see someone writing just "poison" on a bottle i want to feed the  
stuff to him.

You label it with the _CONTENT_ and the _appropriate_ warning signs, which  
here in europe are Xn (Damaging to Health) and N (Damaging to the  
Environment)for both forms of solid CuCl. Look up what is appropriate in  
your country, you can find the warning signs on the web to print out along  
with a nice label if you like.

Then you lock it away somewhere if there are children or exceedingly  
stupid people coming to your house.


ST

At 08:47 07/04/19, Digest Number 2089 wrote:
>     Posted by: "Adam Seychell" a_seychell@... a_seychell
>     Date: Wed Apr 18, 2007 2:40 pm ((PDT))
>
>Len Warner wrote:
> > Do not use anything which looks like a food container
> > (and especially a soft drink bottle) particularly if you
> > expect small children to be around and even if you don't ;-)
>
>And thats why you label your containers, with poison signs.

Unless the folk in your neighbourhood are exceptionally gifted,
small children don't read - but the do recognize shapes and
they do investigate many things by putting them in their mouth.

> > I would recommend neutralizing your effluent with a small
> > excess of garden lime and immobilizing the precipitate
> > by the addition of a little cement. ...
>
>Yes, if end goal of the OP was to ditch the etchant, then I'd agree
>completely. "pcb.easy" seemed to be asking how to collect and store Cu(OH)2.

I understand that, and I'm suggesting that he _should_not_ store it
in its pure form unless he has a purpose for it (which he seemed not
to have, and be at the moment rather lacking in the detailed knowledge
of chemistry required to accomplish such purpose) - rather, he
should render it relatively inert and safe until a suitable opportunity
arises for its disposal.

>     Posted by: "pcb.easy" rpdavidson@... pcb.easy
>     Date: Wed Apr 18, 2007 9:43 pm ((PDT))
>
>My goal is not to collect and store Cu(OH)2, but rather reduce the
>waste by removing the excess water.

It is also a very good idea not to flush metallic contamination into
the water system, unless in exceedingly small amounts.

>The reason for wanting to reduce
>the waste is so that I do not have a large volume of chemicals on
>hand, and do not have to make frequent trips to the hazard waste
>facility.

Yes, but you make those that you have more concentrated
and possibly more hazardous, e.g. by ingestion.

>I can not see how taking a small amount of copper hydroxide
>and contaminating a chunk of concrete and having it buried in a
>landfill is benifical.

It isn't - neither is it very detrimental. This has been discussed
here briefly before.

>Have you seen how they crush and grind
>everything that goes into a landfill.

They don't seem to do that much here - the landfill I used to pass
every working day had recognizable rubbish bags and household
waste items being rolled into its surface. They may be more
discerning of late.

In any case, it doesn't matter: we are talking _small_ amounts
and it will be bound in the concrete matrix, so even if
crushed it won't leach out in large quantities.

>Rather I would like to take it
>to a hazard waste facility and have it properly dealt with.

And until you do, I would rather you didn't have any accidents with it.

>If I was
>willing to have the copper dumped into a landfill and have it
>eventually work it way into the water supply, I might as well pour it
>down the drain.

No, because then it kills the bacteria in the sewage works.
It's not the same as dispersing it in a large amount of solid waste.


Regards, LenW

Len Warner wrote:
> 
>  >And thats why you label your containers, with poison signs.
> 
> Unless the folk in your neighbourhood are exceptionally gifted,
> small children don't read - but the do recognize shapes and
> they do investigate many things by putting them in their mouth.

The labeling is for the sake of people who can read and interpret danger 
signs. As for the remaining people, you simply make the substance 
inaccessible to them. This is common sense.


>  >Rather I would like to take it
>  >to a hazard waste facility and have it properly dealt with.
> 
> And until you do, I would rather you didn't have any accidents with it.
> 

Your overreacting. Copper as the hydroxide is safer to skin and less 
corrosive than the copper in the etchant form. If one can safely use and 
store a hazardous substance like CuCl2 etchant then I'm sure they can do 
the same with copper hydroxide. Note that, ingesting a shot glass of 
either will likely kill you.

Rat LD50 figures:
sodium chloride   3000 mg/kg
copper hydroxide  550 mg/kg

Adam

Hello Group,

I use Tinnit to tin plate my boards after etching.  Tinnit is an
electroless tin-plating solution.  The packaging indicates that it
contains acidic tin salts and no cyanide or other highly poisonous
materials.  I've tried to contact the producer
(http://www.philmore-datak.com/) for information regarding disposal
but I was unsuccessful.  Any disposal tips for Tinnit would be greatly
appreciated.

I also have some MG Liquid Tin to get rid of (spent and a few brand
new bottles).  Tips for disposing of the spent Liquid Tin and/or
takers of the new bottles would also be appreciated.

Finally, I've learned that my area does not have the special haz-mat
pick up day that I've heard about on this group.  I've located my
local haz-mat facility but have not yet interacted with them.  Any
ideas of what to expect?  Will it be expensive?  Will I pay per volume
or per weight? Will they want to know exactly what is inside each of
my carefully sealed and "yuck" labeled containers?

Thanks.

Ed

Snip
> Finally, I've learned that my area does not have the special haz-mat
> pick up day that I've heard about on this group.  I've located my
> local haz-mat facility but have not yet interacted with them.  Any
> ideas of what to expect?  Will it be expensive?  Will I pay per volume
> or per weight? Will they want to know exactly what is inside each of
> my carefully sealed and "yuck" labeled containers?

Ed,
Give  your local haz-mat a call, they will be very helpful. Here in 
Portland Oregon they have a site that is open 6 days a week. It is 
free, they prefer to know what is in the container, but is not 
mandatory. Don't forget to take your old paint, batteries, household 
chemicals, and old motor oil. They will love you for it.

ed.slatt wrote:
> 
> 
> Hello Group,
> 
> I use Tinnit to tin plate my boards after etching. Tinnit is an
> electroless tin-plating solution. The packaging indicates that it
> contains acidic tin salts and no cyanide or other highly poisonous
> materials. I've tried to contact the producer
> (http://www.philmore-datak.com/ <http://www.philmore-datak.com/>) for 
> information regarding disposal
> but I was unsuccessful. Any disposal tips for Tinnit would be greatly
> appreciated.

Electroless tin solutions will typically contain large amounts of 
thiourea as the most hazardous ingredient. Inorganic tin is relatively 
harmless. For small amounts, 500 mL, you could safely dump this on some 
grass and let oxygen and bacteria do the rest. It will also have small 
acid concentration (1%) such as HCl or H2SO4.

Adam

At 08:47 07/04/20, Digest Number 2103 wrote:
>     Posted by: "Adam Seychell" a_seychell@... a_seychell
>     Date: Thu Apr 19, 2007 3:58 am ((PDT))
>
>Len Warner wrote:
> >  >And thats why you label your containers, with poison signs.
> >
> > [snip] small children don't read - but the[y] do recognize shapes and
> > they do investigate many things by putting them in their mouth.
>
>The labeling is for the sake of people who can read and interpret danger
>signs. As for the remaining people, you simply make the substance
>inaccessible to them. This is common sense.

As would be NOT using food containers or other insecure
household containers, if common sense were as common
as its name implies and distributed widely enough to have
reached your neighbourhood in quantity.

> >  >Rather I would like to take it
> >  >to a hazard waste facility and have it properly dealt with.
> >
> > And until you do, I would rather you didn't have any accidents with it.
>
>Your overreacting. Copper as the hydroxide is safer to skin and less
>corrosive than the copper in the etchant form. If one can safely use and
>store a hazardous substance like CuCl2 etchant then I'm sure they can do
>the same with copper hydroxide.

The OP hadn't got to that stage yet.

>Note that, ingesting a shot glass of
>either will likely kill you.

I'm not going to ask which is the more palatable form
nor do I wish to investigate alternative ways of death
or other unpleasant medical consequences.

>Rat LD50 figures:
>sodium chloride   3000 mg/kg
>copper hydroxide  550 mg/kg

That's a 50/50 chance on a very fit rat ;-)

How often do you stake the life of you and yours
on an evens bet?

Do note that there may be chronic effects too,
and a metal burden may be for life - such as it is.

Copper is widely used both as a metal and as a fungicidal
salt, so there is a lot of it about in some parts of our
environment and I agree it isn't generally troublesome.

However...
It is safe as water pipes but not unconditionally safe
as cooking utensils -  it all depends on concentration.

Still, you live a long way from me, so why should I care?
That's what lawyers are for - they care deeply about
what earns them: the next good lunch, or vacation,
or pension plan; but not about who pays for it. Nor can
they repair the collateral damage - only monetarize it.

Len Warner wrote:
>  >Len Warner wrote:
>  > > >And thats why you label your containers, with poison signs.
>  > >
>  > > [snip] small children don't read - but the[y] do recognize shapes and
>  > > they do investigate many things by putting them in their mouth.
>  >
>  >The labeling is for the sake of people who can read and interpret danger
>  >signs. As for the remaining people, you simply make the substance
>  >inaccessible to them. This is common sense.
> 
> As would be NOT using food containers or other insecure
> household containers, if common sense were as common
> as its name implies and distributed widely enough to have
> reached your neighbourhood in quantity.
> 


Secure? I remember seeing pure copper hydroxide sold at the garden store 
in plastic bag inside a cardboard box. Sure it had all the regulatory 
labeling signs, but secure, not. The only difference between poisons 
rated packaging and non-poisons packaging is the word "poison" is often 
molded into the container. Many a food container are perfectly ok for 
storing chemicals such as copper hydroxide. In most cases the only 
difference between food and chemical packaging is the labeling.

This is why I say its ok to store PCB hobby chemicals in suitable food 
containers.

Adam

On Fri, 20 Apr 2007 23:03:09 +0200, Adam Seychell  
<a_seychell@...> wrote:

> Secure? I remember seeing pure copper hydroxide sold at the garden store
> in plastic bag inside a cardboard box. Sure it had all the regulatory
> labeling signs, but secure, not. The only difference between poisons
> rated packaging and non-poisons packaging is the word "poison" is often
> molded into the container. Many a food container are perfectly ok for
> storing chemicals such as copper hydroxide. In most cases the only
> difference between food and chemical packaging is the labeling.
> This is why I say its ok to store PCB hobby chemicals in suitable food
> containers.
> Adam


The ability of a child (or just any exceedingly stupid person) to  
distinguish between a "food" container and a proper chemicals container is  
probably zero anyway.
I'm not saying you should put ferric chloride in a coca cola bottle  
leaving the label unchanged, but i am saying no matter how you label it or  
which container you use, it still needs to be put away somewhere safe.
You can get those "child safe" lids that will only come undone if  
depressed while turning, but i'm not convinced anyone has actually tried  
if children can't get it open anyway.

ST