If it is a single cylinder of H2 rather than bulk, O2 sensors will not be beneficial. A typical lab of 20' x 40' x 10' has 8,000 ft3 volume. A H2 cylinder has 250-300 ft3. A worst case leak (release in 1 minute) would barely move the O2 sensor from 20.9%. Most O2 sensors will alarm at 19.5% which OSHA considers to be O2 deficient. The H2 sensor would go off.. In a release like this the explosion hazard is far greater than asphyxiation.
As noted in the e-mails below, O2 sensors can be finicky, many people are not aware that CO2 can poison the sensor. Please see
http://www.safetyscope.net/wp-content/uploads/pdf/Oxygen%20-%20there%20%20is%20no%20antidote.pdf
Eugene Ngai
Chemically Speaking LLC
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Aaron's Phone
Sent: Friday, July 29, 2016 8:55 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Hydrogen Fuel Cell Questions-O2 sensor...
You are spot on. The O2 sensors cells are easily poisoned and they need servicing and replacement at regular intervals. Best of luck and involve your researchers so that they know they are also responsible for their safety and health.
Aaron Chen, MPH, CIH, FAIHA
Sent from Aaron's iPhone.
I don't disagree with the suggestions for O2 sensors but it is really important to make sure you get the right oxygen sensor. We had an awful time with false alarms-which cause a lot of disruption initially as the building clears out and first responders stream in--and then after a bunch of these, people hit mute buttons and/or come up with very novel re-wiring to turn the alarm off. Talk with someone from the vendor who really understands the different types and what you need for your particular lab set up. We have several of these for our NMR rooms and since we don't have the same application as you do, I don't feel able to give a more specific recommendation, sorry.
Margaret
Sent from my iPhone
I would also use a room O2 sensor for the room. It helps the team to know if oxygen levels are slipping to dangerous levels because of a H2 leak.
Aaron Chen, MPH, CIH, FAIHA
Sent from Aaron's iPhone.
Greetings,
I have a researcher who is intending to start work on a hydrogen fuel cell. I want to make sure I have covered all the bases when I talk with him. The hydrogen sensor has already been purchased, but if you can provide any extra guidance, that would be great.
Thank you,
Margaret Smallbrock
Campus Environmental Health and Safety Manager
Environmental Health & Safety
South Dakota School of Mines
501 East St. Joseph Street
Rapid City, SD 57701-3995
605-394-6020
605-394-5837 FAX
Margaret.Smallbrock**At_Symbol_Here**sdsmt.edu
