>the alarms are extremely uncomfortable for the labs and they end up muting them quite often.   Does anyone have thoughts or suggestions on this? 

This is a good question about an important issue. I recently saw somewhere the observation that
Data isn't information; 
Information isn't knowledge;
Knowledge isn't wisdom.
and the situation you describe points this out. In my mind, maintaining hood containment is in the "wisdom" realm rather than the "data" realm.

My experience is that ventilation engineers often treat hoods and hood alarms as regulatory devices for chemists' behaviors, rather than as tools for managing chemical vapors. If the lab scientists understand the containment properties of the hoods, then they should have the right to mute the alarms. Whether this ability is available depends on the design of the control system. An interesting challenge is that modern hoods are controlled by overall building EMS rather than on a hood by hood basis, whereas alarming is done hood by hood. This gives rise to much of the confusion you describe.

Fortunately, at Keene State, our lab building is small enough to have only one style of fume hood and the chemistry done in our teaching and research labs is small scale and consistent. So I believe that a rough idea of the containment properties of hoods allows our chemists and biologists to work in our hoods without relying on the hood alarms to indicate loss of containment. And as the building ages (it's about 12 years old now), the hood alarms are becoming increasingly unreliable in terms of maintaining calibration. So I am comfortable with them muting the alarms as they need to. This would be a much harder sell to me in a large campus research setting.

Good luck with this.

- Ralph

Ralph Stuart, CIH, CCHO
Environmental Safety Manager
Keene State College
603 358-2859

ralph.stuart**At_Symbol_Here**keene.edu

---
For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org
Follow us on Twitter **At_Symbol_Here**acsdchas