Victoria:

 

My response may seems to simple.  Please see in red below.

 

Mikhail

 

 

Hi all,

 

Here at UVM we have recently moved into a new STEM building (currently containing all of our chemistry and physics labs and a handful of engineering labs) with a central vacuum pump. We previously used tap water aspirators in the old chemistry building. Currently, a Rotary Claw is installed that I'm told is the same as at SUNY Buffalo, George Mason, Harvard FAS, and U Mass Boston. Since we use this to pull vacuum on apparatus containing various solvents, we are being advised to switch to a rotary vane pump like the ones in use at U Pittsburgh, U Maryland, Duke, and Boston College. The risk, as I understand it, is based on certain chemicals' high vapor pressure and low concentration to achieve LEL. Diethyl ether is the usual example here, but hexanes and other common lab solvents also fit this description. I have three questions in particular:

1. Do you have procedural controls that restrict the use of any chemicals in apparatus connected to the house vacuum?  We do not have an established procedure to do so.  But, if very volatile materials are removed, a trap is expected to be used.  However, we do not police such activities to ensure that such approach is being conducted.
2. Do you use point-of-use traps to avoid chemicals traveling to the pump?  Yes, (see answer in item 1)
3. Do you know of any case where a house vacuum system has achieved LEL (or even 10% of LEL) due to lab operations? No, we do not.  Not sure how easy it is to determine if such level is achieved.  Traps will be the easiest and most effective approach under house vacuum.

Thanks for your time and help!

 

Vikki

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802-656-0872

 

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