I still haven¹t seen details on this particular accident, but I think I read
something about a first-year teacher, and something about boric acid and
alcohol. Triethyl borate or trimethyl borate is very flammable and
supposedly burns with a green flame.
The link that I posted includes a very good ³reenactment² animation done by
the CSB [Chemical Safety Board] that shows, for one infamous case anyway,
the teacher¹s prime mistake [in addition to letting the students get too
close, and not using protective shielding]. There is also an interview with
a student, and mention of one $18 million settlement. Most administrators
do understand bad publicity, especially with large $$ attached, so if you
see a dangerous situation, by all means report itin writing. The Powers
might listen better than you expected.
Re the travel of vapors, they can travel many meters to a source of
ignition. A colleague once told me of a case in a building where he worked,
where ether vapors traveled out the door of the lab, down the hall, then
down three flights of stairs to some source of ignition. Of course, once
ignited the fireball travels back to the source of the vapors at hundreds or
thousands of m/sec.
I suspect woefully inadequate training of the teachers relative to chemical
health and safety. Too many of these teachers don¹t even seem to have the
awareness of the bad things that can happen, which is the first phase of a
safe operation.
Steve Stepenuck
On 5/13/18, 9:22 PM, Cary Kilner (Redacted sender "carypq"for DMARC)
wrote:
Folks,
For all of my experience as a demonstrator, I simply do not understand what
goes on with these issues.
I read this and I went on Google and read several of these incidents.
Of course they are written by non-experts who, perhaps, leave important info
out.
I have used methanol and ethanol since 4th grade in my basement.
I have never had vapors creeping so as to produce an unexpected flash-fire.
What the hell do you think these teachers are doing?
In one case, a teacher doing the "whoosh-bottle" outside (good) in a gallon
container (no problem, as long as it's not glass or polycarbonate), let a
student ignite it when she couldn't.
Of course, he stood right over it (with goggles?) and when he lit it, the
"whoosh" shot straight up and burned his face.
I always ignite these with a match taped to a long wooden lecture-pointer.
Note, in one press-release, the superintendent ordered "no more experiments
with flames."
Talk about "throwing out the baby with the bath-water!"
Save us!
W. Cary Kilner
-----Original Message-----
From: Stephen Stepenuck <sstepenuck@xxxxxxxxx>
To: neact <neact@xxxxxxxxxxxxx>
Sent: Sun, May 13, 2018 12:11 am
Subject: [neact] Some follow-up to 17 students and teacher injured in
science demo last week
From today¹s ACS Division of Chemical Health and Safety list [list ³owner²
Ralph B. Stuart, Keene State College]:
Excerpt from full story at
http://www.wkrn.com/top-news/chemistry-safety-experts-warn-schools-to-stop-u
nsafe-science-demonstrations/1172474948
