I'm mostly gathering thoughts, articles together for (potentially) a longer comment on the Beacon School "rainbow flame" experiment. Still haven't come up with any great thoughts yet.
Here's the New York Post's account of the accident. This section is detailed (almost too detailed; I am withholding judgment until I see more):
A more sober account of the regulatory aspects (including our favorite CSB investigator, Mary Beth Mulcahy) is in the New York Times' longer look at the Beacon School incident.
It will be very interesting to see what sort of initiatives flow out of this incident or if it will be ignored. Clearly, the UCLA incident (and legal coercion from the Los Angeles District Attorney) were enough to get changes in University of California procedures. Will such things flow out of the Beacon School incident?
Here's the New York Post's account of the accident. This section is detailed (almost too detailed; I am withholding judgment until I see more):
...Two sophomores were injured in the explosion. Alonzo Yanes, 16, remains at Cornell Medical Center’s burn unit with second and third degree burns to his face, neck and torso; Julia Saltonstall, 16, suffered first degree singes to her arm, torso and face and was treated and released.
“It’s absurd that those students weren’t wearing goggles,” said one source. “It’s lucky they weren’t blinded.”
Additionally, the teacher poured the highly flammable alcohol out of a gallon container rather than having on hand only the few milliliters necessary, one source said, speaking of the ongoing investigation on condition of anonymity.
Finally, and most critically, Poole did not ensure that the fire had completely gone out in all four crucibles used in the experiment.
Unbeknownst to her or her students, one of the ceramic vessels still had a low, clear, barely visible fire...The invisible flame aspect of methanol is not necessarily well-known.
A more sober account of the regulatory aspects (including our favorite CSB investigator, Mary Beth Mulcahy) is in the New York Times' longer look at the Beacon School incident.
It will be very interesting to see what sort of initiatives flow out of this incident or if it will be ignored. Clearly, the UCLA incident (and legal coercion from the Los Angeles District Attorney) were enough to get changes in University of California procedures. Will such things flow out of the Beacon School incident?
I feel bad for the students that were injured, but I can easily see how a teacher might make this mistake. Some people, even after course work in Chemistry, cannot imagine the difference between adding MeOH from a dropper versus from the bottle.
ReplyDeleteAs a high school teacher (I forget the exact details) one of my students accidently set the natural gas spigot, which was open, a flame with a sparker. Based on the MeOH observation above I would have thought the whole gas system would blow up but all we got was the flame. Im using this example because most scientifically trained people make analogies to rationalize changes in procedures. If its safe from a dropper, why shouldn't it be safe from a MeOH jug? But its still difficult to predict what could happen upon scale-up.
Because there is no air in a gas line, there is no way for the flame to propagate in. A MeOH bottle has airspace above. When the fumes combust with air present, the pressure rise will eject flaming MeOH out the spout if the bottle is angled appropriately.
DeleteHow a scientist does not understand this is unacceptable. Its a case of being coddled with safety regulations to the point of no one having experience with fire, and not understanding it.
Once you have made an observation or have heard of an observation, its pretty easy to come up with a mechanism of action, as you have ablely done. Sine there is pretty good knowledge of how combustion occurs, I have little doubt that your mechanism of action is correct (if this was a biological issue where less is known than your mechanism would have probably been wrong).
DeleteFor someone who has never seen, heard, or thought about a MeoH bottle explosion, and has not thought about this in detail because it was brought up in this post or in articles that are out there, imagining what might happen may be more difficult. I think its pretty easy for a high school chemistry teacher to be in this circumstance. I am not sure how this lack of knowledge and foresight can be solved, except for what the poster below said.
This is a response to Anonymous quote on January 8, 2014 at 8:50 AM.
Delete"...eject flaming MeOH out the spout if the bottle is angled appropriately"
There may be several possibilities when flame reaches an open methanol container.
The angle of the bottle is one variable.
Whether methanol is being poured is another variable.
It may be that ejection can happen regardless of the tilt of the bottle.
It may also not be necessary that liquid be currently pouring for this to happen.
The following all seem possible:
1) for a vertical open bottle - flame at top of bottle
2) container shatters due to explosion
3) violent ejection of liquid and gas with flames
4) perhaps it will not always ignite immediately
For the third possibility, if a violent reaction with turbulence gets going inside the bottle, methanol will most likely be ejected regardless of the angle of the bottle.
BELOW ARE TWO EXAMPLES OF INCIDENTS
LIT MATCH DROPPED INTO BOTTLE
In one incident (Minnesota) a lit match was apparently dropped into a methanol bottle.
http://minnesota.cbslocal.com/2011/12/01/3-students-burned-at-maple-grove-junior-high-school/
<<<<<<<<<
From link:
Neuberger had a front seat to the demonstration when he said his teacher lit a match. Three other students surrounded him.
“He just took a jug of menthol and dropped a match in there. That’s like the last I know,” he said.
<<<<<<<<<
CONTAINER SHATTERED
Example of the explosion shattering the container:
http://articles.latimes.com/1999/sep/01/news/mn-5644
Methanol Blast in Class Sends 23 to Hospital
September 01, 1999
I think in the previous article on here someone mentioned how a PhD-trained chemist probably wouldn't be making these mistakes after gaining knowledge of how to work with all kinds of nasty chemicals, but there is something more important here. Certainly PhD-trained chemists spend years developing good techniques, but the basic safety measures are learned quickly. I don't understand how school districts can't hire somone to be a safety coordinator and have teachers go through a refresher covering these kinds (don't poor a bottle of methanol out when a flame might be near...) of practices once a year. It could be a day or two over the summer (most teachers already have plenty of useless instructional training time; lets have them learn something useful).
ReplyDeleteWhen I worked with the government we had people whose job was practically to tell us how to drink from a water fountain! It doesn't seem unreasonable to have better safety training on general safe chemical handling procedures for teachers who might not have previous had this training in their educational tracts. Hopefully we will start to see more of that in the future.
Sure, they could hire a safety coordinator. But how do they know if that person has the needed skills? What is their primary purpose? What are they going to do when they aren't doing training. Are they going to do safety inspections of all of their schools? If so, you want someone who is highly trained, educated, good at teaching and training, and an expert in multiple subject areas. How much is this going to cost? Remember that we can't fund basic education here. Would you like to know how many school districts there are in Washington State?
DeleteAlso realize that as an educator, I am "highly qualified" to teach chemistry despite having little chemistry lab training and none of it recent. I have interviewed for many jobs that would require teaching a class of chemistry. The only surprising thing is that more accidents don't happen.