H2/N2 mixtures greater than 5.7% H2 are flammable, therefore a different level of hazard than the 5% mix. In the presence of an ignition source you could have one heck of an explosion.

I would question the.researcher's need for these mixes and the safeguards he will be putting in place.

If you still decide that you want a richer hydrogen mix, I strongly urge you to have it pre-mixed by a specialty gas lab. Our labs at Airgas use a patented Gravimetric system -Accugrav - for custom blends, which I believe is the most accurate in the compressed gas industry.

So again - take a second look at whether thats really what you want/need, what safety measures you will have in place, and if you choose to go forward, have a Spec Gas Lab mix it for you.

There is a lot of danger inherent to using hydrogen, and a lot of potential for harm to the people using it. Please be safe.

Note- In training for your personnel, I would review the hydrogen explosion at University of Missouri last year

Todd Perkins

Regional Safety Director

Airgas USA,LLC

-------- Original message --------
Subject: [DCHAS-L] FW: Hydrogen
From: Wayne Phan <Wayne.Phan**At_Symbol_Here**POMONA.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
CC:

Hello,

A colleague of mine has a question about hydrogen and nitrogen mixture. Please advise.

See email below.

Thanks,

Wayne




Hi Wayne, I have a question for you. I'd like to use 80/20 H2/N2 or other high % mixes of hydrogen. I have never used more than 5% before. We would not use it much and would not use large volumes-we would bubble the gas into sealed 100 ml bottles of fluid to equilibrate the gas and that's it (in other words, we would never have hydrogen gas flowing for more than a couple minutes at a time, and in very small amounts).
Any idea where I could look for guidelines, etc? Thanks, ejc

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