It has been about 20 years, but for about eight years, I had experience working with anaerobic bacteria in glove boxes, I can share some of my experiences.

We had two models—the Coy model was essentially a giant flexible plastic balloon with four taped gloves on them.  The other model, Forma, was a rigid plastic box with a plastic front that had the gloves on it.  Both models had an airlock.  Our internal atmosphere was 80 % N₂ 15 % CO₂ and 5 % H₂.  Because we needed to manipulate cultures with the gloves, it was not a good thing to have the gloves poking out—using them increased the pressure inside the glove box, which tended to create leaks where none had existed.

First thing:  the reason for the H­₂ was that the plastic was permeable to O­₂, which was bactericidal to many of our cultures, and bacteriostatic to the rest.  We had palladium catalyst pellets in the box which allowed any O­₂ that diffused inside to combine with the H₂ to create water.  We monitored the H₂ level inside the box carefully (for obvious reasons) and kept dessicant crystals in the box to deal with the moisture problem.  We roasted the palladium pellets and the dessicant crystals in an oven each day.

As for leaks, in the main glove box, we had a hand-held air flow meter (chirped if flowing air crossed the sensor)that we used on all the seams (e.g. places where gloves were taped into place).  We surveyed the seams each Friday, after any glove change, or if we suspected a leak (our usual tell tale sign was that the glove box deflated.  Believe it or not, this was pretty reliable.)  We also used the soapy water trick on the gloves, but more often, this was our test for whether the gas tanks were leaking.

As for the airlock, we pulled a vacuum on it each night.  If the seal on the airlock was compromised, the vacuum would be gone.

So, we had lots of checks for leaks.  No one check was ever enough.  The important thing of course is that whatever method you use to monitor whether the box is leaking, keep records so you can spot trends.  Also, check with the glove box’s manufacturer.  They will be invaluable with this.

The box does have a gauge on it. I asked the lab folks if they look at it. They said their test was that if the gloves were poking out, then they knew it was ok. !!  I did remind them that once they graduate & go to a "real" job, recording things like pressure gauges in their lab book or checklist were considered basic requirements for any work. They said they'd set up a log sheet to do that. Can't make this stuff up!

Kim Auletta
Lab Safety Specialist
EH&S    Z=6200
Stony Brook University
kauletta**At_Symbol_Here**notes.cc.sunysb.edu
631-632-3032
FAX: 631-632-9683
EH&S Web site: http://www.stonybrook.e du/ehs/lab/

Remember to wash your hands!

From:	Christopher Suznovich <snuz**At_Symbol_Here**MAC.COM>
To:	DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Date:	11/08/2010 07:18 AM
Subject:	Re: [DCHAS-L] Glove box inspection checklist?
Sent by:	DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>

If you are just looking to to ensure there are no leaks of gas from the box or into the box, you could do a pressure test to determine if the pressure  remains with an acceptable limit once filled with argon.  The opposite can also be done by performing a vacuum test, drawing a complete vacuum inside the box and determine if the vacuum holds then you would know that there are no leaks.  

You could also leak a container of liquid smoke inside the box, purge the box with argon or any other gas and once under pressure watch to see if any of the smoke escapes from the box.  

Chris

From: Kim Auletta <kauletta**At_Symbol_Here**NOTES.CC.SUNYSB.E DU>
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**list.uvm.edu>
Date: Thu, 04 Nov 2010 14:15:00 -0400
To: <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Subject: [DCHAS-L] Glove box inspection checklist?

I have a lab that is using a glove box to maintain an inert atmosphere with argon while working with lithium ribbon. While the operation looks ok on the surface, they can't document or prove that they haven't had any failures (research labs are not production & no one ever thinks of these things!). Does anyone have a glove box inspection checklist or other info they can share?

Thanks in advance for your help!

Kim Auletta
Lab Safety Specialist
EH&S    Z=6200
Stony Brook University
kauletta**At_Symbol_Here**notes.cc.sunysb.e du
631-632-3032
FAX: 631-632-9683
EH&S Web site: http://www.stonybrook.edu/ ehs/lab/ <http://www.stonybrook.edu/ ehs/lab/>

Remember to wash your hands!