Roger et al,
Been awhile Dr. Roger
Old friends should talk from time to time.
As Holmes required a Pr. Moriarity, I need a worthy adversary to keep me on my toes.
What comes to mind from "sewer gas" if hydrogen sulfide (H2S). At breathing levels above 500-1000 ppm, unconsciousness will occur and death will follow withing 5 minutes or less, unless EMS arerives and does the wonderful things many of us have taught them, and then only if somebody remembers that the sodium nitrite component of the Nithiodote(R) kit) is administered and only if it is done as as slow IV infusion with monoring of the blood pressure (you can kill folks doing this wrong, but there is a way to do it right). The sodium thiosulfate part will do nothing (although somewhat unlikely to do any harm).
Methane or any of the simple alkane gases can in a confined space case simple asphyxia. The only treatment for that is oxygen and airway management.
A ha-penny for my thoughts, and you may donate it to the good charity as you wish.
But, eventually, as in Peter and the Wolf, eventually the Wolf came and tried to wreak havoc. It ls left to us as safety professionals, to understand how the wolf might behave and in ol' TX cowboy terms, cut him/her off at the pass.
Alan
ahalltoxic**At_Symbol_Here**msn.com
Date: Mon, 29 Apr 2013 09:22:13 -0700
From: roger.o.mcclellan**At_Symbol_Here**ATT.NET
Subject: Re: [DCHAS-L] Chemistry Fume Hood Experience
To: DCHAS-L**At_Symbol_Here**MED..CORNELL.EDU
When you have repeated alarms the system is not crying wolf, it is telling you that you have a potentially serious ventilation problem in your building and laboratories that deserves urgent attention. By allowing students and, I presume, faculty and staff to over ride the safety system you are condonning inappropriate behavior. If you are the responsible authority you are opening your self up to legal action some time in the future from alleged victims of exposure to xyz. You need assitance now from some professional ventilation engineers to do a comprehensive ventilation analysis of the entire structure and the individual laboratories.
It has been my experience that many institutions have not given adequate attention to ventilation issues when facilities were built and modified and, especially, when an investigator decides to add a hood. The attitude is frequently --after all it is just one hood. Overtime, the installation of a hood here and one there adds up to 15 additional hoods with no attention given to the need for additional makeup air.
As I recall there was an interesting example of this a decade or so ago at the Univ of Cincinati Dept of Environmental Health. The Dept Chair at the time did not think it was a serious sick building syndrome problem until he collapsed one day leaving the build. Tuned out thay had all kinds of ventilation issues including an elevator that "pumped" sewer gas from the bottom of an elevator shaft..
Safety systems are iinstalled for good reasons, do not ignore them.
Roger O. McClellan
From: Mary Ellen A Scott < mas35**At_Symbol_Here**CASE.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Mon, April 29, 2013 9:01:39 AM
Subject: Re: [DCHAS-L] Chemistry Fume Hood Experience
The biggest issue we have is supply air or lack there of. At least all are VAV hoods go into alarm so much that the students just put paper in the MUTE button. We seem to have created a cry wolf situation.
