Storing etchant safely

[burningman]

I am considering the HCL/H202 etchant and looking for advice on the safest location for storing HCL in one's home.

I'd like to store the HCL and used etchant in my attached garage, but I am worried about the dangerous vapors that emit from the HCL and used etchant and what they might do to my health and home. Something tells me that containing the materials in a garage may not be a good idea.
Any advice would be appreciated. Thanks.

[Schappy]

http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/

[burningman]

I guess I should be asking - are the fumes off the unmixed HCL, etchant, and used etchant too dangerous to be storing in a garage?

[defaced]

The HCl is safe to store in the container it's sold in provided the lid/cap is tight.  I use the same etchant at work for metallographic samples and the H2O2 tends to off gas O2 so I vent my storage container until pressure buildup isn't noted - usually once or twice within a couple of hours of using the solution.  I would however store all of this stuff out of reach of any young ones; preferably locked if you have the ability. 

[burningman]

Thanks for your reply.  Does anyone else keep their etchant materials and used etchant in their garage?

[KazooMan]

I have only worked with ferric chloride or persulfate etchants so I do not have any direct knowledge to offer to you.  I do have 40 years of lab experience as a synthetic organic chemist and I can offer a few comments about the individual reagents.

In part the storage issue would depend on how hot it gets in your garage.  People buy muriatic acid (fairly concentrated HCl) off the shelf at the hardware store for cleaning masonry and I imagine they store it in the garage or basement.  The fumes ARE very corrosive and irritating.  You should only open the container in a well ventilated area or perhaps outside.  Wear rubber gloves and eye protection!!  Add the concentrated acid to the aqueous peroxide solution not the other way around to keep heating under control.  When you are finished with the HCl, be certain that the neck of the bottle is free of any residual acid before you recap.  Otherwise the residue will release corrosive vapors that can attack metals.

In a chemistry lab, concentrated HCl comes in glass bottles with tight caps.  Most modern bottles have a thick plastic coating to help contain the acid if the bottle is broken.  You would not want to drop a bottle of your etchant and have it splash on your legs.

The hydrogen peroxide has its own issues.  As was mentioned previously it decomposes to give off oxygen gas.  This could cause a pressure buildup and potential explosion of the container.  In the lab concentrated solutions of hydrogen peroxide (30 - 70+ percent) are stored in plastic bottles and kept refrigerated.  The caps on the bottles usually have a teflon disk in then with a slit across it.  This aligns with a small hole in the cap.  This provides an adequate seal to keep the reagent in the bottle while allowing release of any pressure buildup.  The concentration of pharmacy store hydrogen peroxide is much lower (about 3% for antiseptic use and up to about 10% for bleaching) and the plastic bottles you get generally are not vented.  With the lower concentration of peroxide in the etchant a vented cap should not be necessary, and would likely release HCl fumes anyway.   As was mentioned previously, you should vent your used etchant bottle a few times over a period of hours after use until you are confident that there is no pressure buildup.  

Keep in mind when disposing of any  used etchant solution that the dissolved metals pose a toxicity hazard.

[burningman]

Thanks for the detailed response KazooMan
I'm thinking that I might just find a plastic storage bin, that I can lock and put everything outside.
Regards.