Chromatography Forum

When hydrogen is used as a carrier gas, a few mL/min exit the GC. Agilent recommends venting to a fume hood or outside. Is that just safety theater? It's hard to see how a few mL could do any real harm.

Don't get me wrong, I would like a path to a fume hood or to outside and have been asking management for one for two and a half years. But I want it mostly because I'm running PCBs on an ECD. I have a carbon trap but I'd rather not have to bother with that.

I'm thinking of just running short lengths of tubing from the split vent, septum purge, and ECD exhaust line and have them all join together before finally venting out. It would be a mix of 90% nitrogen and 10% hydrogen. No real fire risk that I can see. Thoughts?

We were told once that hydrogen dissipates so quickly there should rarely ever be a fire risk unless you had maintained column flow into an MSD with pumps off.

We have over a dozen systems, all were converted years ago to hydrogen, and we've had no safety concerns.

Agilent has a video showing how difficult it actually was to have a hydrogen explosion in a GC even when intentionally trying.

That said, an Agilent engineer told us with the size of our GC room and the 24/7 ventilation there, that we would never even come close to getting near the hydrogen explosive threshold.

So what did we end up doing? Well, our anal retentive OCD manager had seen the footage of the Hindenburg explosion so was very wary. He ended up buying two 20 foot lengths of stainless steel tubing and PERSONALLY routing the vent flow around the perimeter of the room into the exhaust hood. ONLY HE could connect those SwageLok fittings. Funny, because for three decades prior I was able to fit hydrogen lines to the GC units, I knew how to leak check, etc.

Agilent has a video showing how difficult it actually was to have a hydrogen explosion in a GC even when intentionally trying.

That said, an Agilent engineer told us with the size of our GC room and the 24/7 ventilation there, that we would never even come close to getting near the hydrogen explosive threshold.

So what did we end up doing? Well, our anal retentive OCD manager had seen the footage of the Hindenburg explosion so was very wary. He ended up buying two 20 foot lengths of stainless steel tubing and PERSONALLY routing the vent flow around the perimeter of the room into the exhaust hood. ONLY HE could connect those SwageLok fittings. Funny, because for three decades prior I was able to fit hydrogen lines to the GC units, I knew how to leak check, etc.

Ha, dramatic!

Letting it dissipate sounds safer to me than having a tube full of it with an open end - you could get a pretty decent 'bark' from that probably!