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[Phys-L] A knowledge of chemistry may save your life ...



<Sorry for the cross-posting.>

On 16 March, an explosion in a biology laboratory amputated the arm of
a post-doc and destroyed the laboratory. They were culturing bacteria
in an environment that (supposedly, see below) was 70 % H2, 20 % O2,
and 10 % CO2. For consistency, they pressurized a 50 L tank with this
mixture.

By now, anyone with a modicum of chemical awareness will be recoiling
in fear. Indeed, I am surprised that they were conducting experiments
with this procedure for three years without incident.

The final report was recently released and is available from
http://www.hawaii.edu/news/2016/07/01/independent-investigation-of-lab-accident-complete/

I want to emphasize that this lack of chemical awareness is
wide-spread, even amongst people who should know better.
For example, chemists make H2:O2 balloons for use in class.
https://www.youtube.com/watch?v=RGRlEHEuoxQ
Many of us wistfully wish for some way of getting a 67:33 mixture. On
a whim, I asked the local gas supplier if they could provide me with a
H2:O2 (67:33) mixed tank. They looked into it, and the answer was
YES!! 2000 psi just waiting to detonate. No thanks.

On a scientific note, the H2, O2, and CO2 mixture used in the biology
experiments is not miscible; the gases will separate inside the tank
unless continuously mixed. If they draw from the top, they will draw
out H2 first, then an O2/CO2 gradient. Thus, the scientific output of
this group is flawed. (How do I know? Physical chemists use mixed
gases too. And I watch balloons.)

Dr. Roy Jensen
(==========)-----------------------------------------¤
Lecturer, Chemistry
W5-19, University of Alberta
780.248.1808