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Natural Products

University of Hawaii lab explosion likely originated in electrostatic discharge

The root cause was failure to recognize and control the hazards of explosive gas mixture, investigation report says

by Jyllian Kemsley
July 7, 2016 | APPEARED IN VOLUME 94, ISSUE 28

Credit: Honolulu Fire Department
The blast caused a postdoc to lose an arm and about $800,000 in lab damage.
Credit: Honolulu Fire Department
The blast caused a postdoc to lose an arm and about $800,000 in lab damage.

An electrostatic discharge between postdoctoral researcher Thea Ekins-Coward and a gas storage tank containing hydrogen, oxygen, and carbon dioxide likely caused an explosion at the University of Hawaii, Mānoa, in which Ekins-Coward lost one of her arms, according to a report by the University of California Center for Laboratory Safety (UCCLS).

UH hired UCCLS to conduct an independent investigation of the March 16 accident and released the report on July 1. Another investigation by the Honolulu Fire Department, released in April, concluded that the cause was a spark from the pressure gauge. UCCLS dug deeper than the fire department and contracted with an outside laboratory to recreate and test the experimental setup. Those tests ruled out all causes other than a static discharge.

Safety recommendations for working with explosive gas mixtures:

▸ Calculate the potential explosive force to determine level of protection

▸ Compose detailed and thorough standard operating procedures

▸ Conduct specialized training on highly explosive materials

▸ Use well-designed, hazard-rated equipment (intrinsically safe as a minimum rating)

▸ Electrically ground and bond equipment

▸ Use blast barriers

▸ Use engineering controls for highly explosive materials

▸ Use work practice controls to limit access

▸ Conduct outside review of procedures, equipment, and engineering controls

Source: UCCLS, “Report to the University of Hawaii at Manoa on the Hydrogen/Oxygen Explosion of March 16, 2016,” part 2

Going beyond the immediate cause of the explosion, however, “the overall underlying cause of the accident was failure to recognize and control the hazards of an explosive gas mixture of hydrogen and oxygen,” the UCCLS report says.

“The message to other researchers is that they need to do a better job of educating themselves about the hazards of the materials they’re working with” and what could go wrong, says Craig A. Merlic, UCCLS executive director and a chemistry professor at UCLA. And campus safety personnel “need to have conversations with researchers and guide them to the resources that are available” to help conduct experiments safely, he adds.

In the case of the UH explosion, for example, the lab passed a safety inspection in January in part by properly storing H2 and O2 cylinders 6 meters apart. But no one questioned storing a mixture of the gases in a 49-L steel tank designed for compressed air and not electrically grounded, the UCCLS report says. When the tank exploded, it contained 55% H2, 38% O2, and 7% CO2 at a pressure of 8 atm. UCCLS estimated the energy of the detonation to be equivalent to 70.5 g of TNT.

Ekins-Coward was working for the Hawaii Natural Energy Institute under researcher Jian Yu. The gas mixture was used to feed bacteria to produce biofuels and bioplastics. Yu’s lab is still closed, and he and the institute have not yet determined how experiments will be set up going forward, says institute director Richard E. Rocheleau.

The explosion cost about $716,000 in infrastructure damage and $60,000 to $100,000 in equipment losses, and UCCLS was paid $88,000, says UH spokesman Dan Meisenzahl.

UH placed no restrictions on the UCCLS team during its investigation, Merlic says. The Hawaii Occupational Safety & Health Division is also examining the incident.



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Jyllian Kemsley (July 13, 2016 1:35 PM)
Hemant Desai (July 13, 2016 3:02 PM)
Is earthing always the best approach to preventing explosions due to electrostatic discharge?
Maintaining equipotential between people and explosive materials/mixtures is a consideration for our Labs.
(July 16, 2016 12:44 AM)
Earthing allows a stray current to be dissipate safely
Jack Hipple (July 13, 2016 3:29 PM)
In addition to all the previous comments and analysis, I am amazed at the lack of understanding of the fire triangle. (Fuel, oxygen, ignition/heat). Ignition sources are EVERYWHERE. A pressure gauge is only one of many. Static discharge is generated from movement of any kind. As a chemical engineer who teaches the basics of ChE to chemists and other non-ChE's for AIChE, this is the first topic that is covered in this training. This is basic, elementary safety.
Vadim Krongauz (July 13, 2016 4:01 PM)
Lack of basic erudition in academia is evident: every 5th grader heard about Hindenburg explosion and hydrogen-oxygen mixture tendency to form water explosively upon a slightest provocation. In GC lab setting we are instructed to keep hydrogen and oxygen tanks 20ft apart in isolated cabinets. So how did it occur that a post doc and professor did not mind mixing hydrogen and oxygen in large quantities? Who come up with the brilliant experiment?
A.F.Webb (July 13, 2016 6:50 PM)
It's still a bit puzzling. The explosion occurred inside the steel tank. How did a static spark get in there, whether or not the tank was grounded?
Eugene Ngai (July 14, 2016 12:52 PM)
As testing has shown, the tank system was a very well insulated system. What occurred was a charge transfer from the researcher to the tank or the reverse. This electrical charge as it traveled through the metal most likely created a corona or brush discharge within the pressure gauge stem which was exposed to the H2/O2 mixture. This was an internal discharge which can cause the minute energy to ignite the mixture. Electrostatic charges for electronics is a serious problem. Ungrounded people can cause small currents of 100-200 v that can damage the device. This is a charge transfer from the researcher into the device. Since we were barred from doing any destructive testing, we were not able to pinpoint where this corona discharge could have occurred.
An area we did not pursue was the possibility of the researcher sitting on the chair that was violently damaged. We were not able to question her on the events leading up to the incident. Could she have created a high charge as she slid over to turn the tank pressure gauge off? The damage to the chair and other visual clues would suggest that this happened
FGS JML (July 13, 2016 8:14 PM)
It is very unlikely that there was ever a spark inside the tank; ignition most likely occurred downstream of the tank outlet and the flame front traveled back into the tank. Which raises The question: why would anyone EVER put a mixture of fuel and oxidant in the same vessel? (Unless of course they were TRYING to build a bomb.)
Eugene Ngai (July 16, 2016 10:39 PM)
I had considered that but the rupture of the tank and the direction of the pieces clearly indicated ignition at the pressure gauge. If it was at the valve it would not have been ejected straight up impacting the light fixture. The low energy required doesn't require a spark (arc) which is over 10 mj. The mixture can ignite at 0.0015 mj
David Dodds (July 13, 2016 10:51 PM)
I realize my comment is after-the-fact, and that a scientist was seriously injured and maimed in the event. But a container filled with a mixture of hydrogen and oxygen is a bomb. If special training, MSDS review or safety committees are required to understand this, then there has been a total failure of the educational system.

Two (or three) mass flow controllers and a mixing valve would have done a much better and safer job of feeding a gas mixture to the bacteria. But even then, I would be worried about creating an explosive gas mixture in the headspace of the fermentor or incubator.

It is all very easy to write this, and wring our hands afterwards. But I have a question. I started hands-on organic chemistry at college just over 40 years ago, before MSDS, right-to-know, safety review committees and lab inspections existed. We handled all the reagents that are handled in labs now (and some that no longer are), many in glass bottles without safety boots, etc. Yes, I had some near misses. I cleaned up afterwards and learned my lesson. My question is - how did we manage to stay safe without all the current safety procedures?

I don't have a good answer - although obviously we managed somehow. The best I can come up with is that we "assumed everything was dangerous", unless we definitely knew otherwise, and acted accordingly. And I know we also looked out for each other, and generally knew what the folks around us were doing, and would ask questions if we thought something was odd or dangerous. Ore we would just ask how to do something if we hadn't done it before - like fill a reaction flask with liquid ammonia out of a tank, fill a hydrogenator, initiate a Grignard, etc. No safety classes, no committees, no "conversations to guide people to resources", no paperwork - just what we used to call common sense, and paying attention.

I have a further answer. We all (yes - all of us) had made gunpowder and guncotton, stuck spatula tips of inorganic salts into Bunsen burner flames to see the colours, dropped a bit of sodium into a beaker of water, taken a bit of white phosphorus out of the water it was stored in, dissolved coins in conc HNO3 to extract the silver, ran water electrolysis collecting the hydrogen in a Coke bottle and igniting it, and dropping a bit of burning magnesium in the jar that had the oxygen in it, etc etc . In high school. Things that would literally get a person arrested today.

And we learned that things could be dangerous.
Andrew Babij (July 18, 2016 11:02 AM)
Although you and I survived uninjured, I don't think we stayed safe. I'm sure there were plenty of injuries and deaths. It was viewed as a cost of doing business. There were no statistics.
The emphasis on safety has resulted in the American workplace - labs included - getting less and less hazardous since the advent of OSHA in 1970 and the subsequent RTK regulations.
Joel Baechle (July 14, 2016 3:01 AM)
I work with explosives as my daily job - I went way beyond a little home-made gunpowder. Hindsight notwithstanding, the "cause" might have been politics and competitive pressure, or inexperience and over-confidence. The researcher is lucky to have lived through the event at all. 70g TNT equivalency is enough bang to embosss steel into gravel like boiled lettuce. The "cause" of the Space Shuttle Challenger disaster is pretty well-known: political pressure pushing the engineers and data to the side. My neighbor in Hunstville, Alabama was one of Von Braun's team from Peenemunde, and the O-Ring failure was not a "surprise". It was politics and money that did it. So in spite of all the increased paperwork today, don't discount the social aspects.
David Dodds (July 14, 2016 7:24 PM)
Your point about the social aspects isa ggod one, and is what I was trying to articulate from a positive aspect. We managed to stay safe all those years ago by having a cooperative, rather than competitive or "too busy to worry about anyone else" social environment. This was because we all had a sense of what was dangerous, and we had all learned that from the experiences I mentioned.
Hugo Vogel (July 14, 2016 4:12 AM)
I only can affirm David Dodd. Unless you never have done yourself all of those funny experiments with explosives (of course with small amounts and proper safety measurements), you do not have the right feeling of what it can do, if using bigger amounts of chemicals. Absolutely crazy to store a mixture of an almost perfect 2:1 mixture of Hydrogen : Oxygen in a vessel and at a pressure of some 8 atm in such an amount, and this inside a lab. As a teacher of Chemistry I used to demonstrate the detonating gas by igniting the above gas mixture in a small glass bottle. Even worse are mixtures of Oxygen with Methane ore other Hydrocarbons like Propane or Ethin.
To use continuous mixing devices is a laboratory standard which should have known to a postdoctoral researcher, regardless of what basic training he or she had bevor.
To control the mixing rate a simple GC is available.
Hugo Vogel (July 14, 2016 4:16 AM)
I only can affirm David Dodd. Unless you never have done yourself all of those funny experiments with explosives (of course with small amounts and proper safety measurements), you do not have the right feeling of what it can do, if using bigger amounts of chemicals. Absolutely crazy to store a mixture of an almost perfect 2:1 mixture of Hydrogen : Oxygen in a vessel and at a pressure of some 8 atm in such an amount, and this inside a lab. As a teacher of Chemistry I used to demonstrate the detonating gas by igniting the above gas mixture in a small glass bottle. Even worse are mixtures of Oxygen with Methane ore other Hydrocarbons like Propane or Ethin.
To use continuous mixing devices is a laboratory standard which should have known to a postdoctoral researcher, regardless of what basic training he or she had bevor.
To control the mixing rate a simple GC is available.
Dr. Otto Herrmann (July 14, 2016 7:30 PM)
I am surprised that there was no apparent requirement for a documented safety analysis. If that WAS done and it missed this situation, then the people involved need a REALLY SERIOUS review of capabilities and training. If none was done then the question is whether this is standard practice in universities? Certainly unavoidable in industry where I have worked for decades. A number of comments above do question the knowledge of the professor and post-doc - and I have to echo that. I would have expected everyone with at least high school science to be aware of the properties of hydrogen + oxygen - or I am being nostalgic in my expectations?
Karl O. Christe (July 19, 2016 7:16 PM)
A. F. Webb raised a very valid point. The steel cylinder should act as a Faraday Cage and an electrostatic discharge could not have occurred inside the tank.
There is not necessarily a need for a spark to set off a reaction. Catalysts can also initiate a reaction between hydrogen and oxygen and was demonstrated by Doebereiner in the 19th century. As pointed out already repeatedly, mixing of large amounts of hydrogen and oxygen in a tank, particularly at elevated pressure, is inconceivable and should have never been done.
Eugene Ngai (July 25, 2016 10:29 PM)
This may be true for a tank with all the attachments fully conductive. There were a number of attachments that were not fully bonded to the tank.
Benjamin Hall (December 31, 2016 5:13 PM)
Was it determined the discharge occurred inside the tank at the electronic pressure gauge connection due to part of the gauge itself being electrically insulated from the tank, or the entire gauge body, due to PTFE thread tape? I could see either condition mimicking a spark plug.
Don theobald (July 22, 2016 5:52 PM)
The Challenger disaster would have been avoided with 8 heating blankets maintaining o-ring pliability until launchtime
vijay sharma (July 27, 2016 6:43 AM)
Hi Vijay

Static discharge in lab is very dangerous especially if we handle H2 and O2
kwest (November 11, 2016 1:55 PM)
We should all be careful with tendencies to dismiss this as a professional "should have known better" as it fosters a normalization of lab risks. Rather take this as an opportunity to challenge ourselves and students to think about risks they take with experiments and if there are some components they have missed and how they will mitigate it effectively.

Remember if you've had a near miss in your past that means luck was the only barrier keeping you from being in this person's shoes. We can all agree luck is no barrier at all.
dan (March 1, 2017 12:37 AM)
This tragedy was not caused by a spark from the pressure gauge. Neither was it caused by static electricity.

This tragedy was caused by criminal negligence or more likely recklessness (which is a more serious crime than negligence)
The definition of negligence follows the reasonable person standard:

"A failure to behave with the level of care that someone of ordinary prudence would have exercised under the same circumstances."

Would have a person of ordinary prudence have mixed a large quantity of an oxidizer and a highly flammable gas in a pressurized vessel?

The answer is clearly no. Any kid that has witnessed the explosion of soap bubbles filled with H2+O2 can attest to that.
That would be an interesting experiment. go to the next high school and ask random kids "hey you, is it safe to mix hydrogen and oxygen in a steel tank?". I bet that most kids would say no.

But these people were not kids, they were trained scientists with phds. They could reasonably have foreseen what would happen.

Therefore this explosion goes beyond criminal negligence. Clearly the people involved had foreseen the possibility and consciously taken the risk. After they had a close call, there is no way to claim that they were not aware of the risk. This is not criminal negligence anymore, this is reckless behavior.

I fear that we are going to continue seeing deadly accidents in university labs
- no safety culture
- sub-standard labs crammed full of equipment
- high turnaround
- can-do attitude, work is too important for safety
- cutthroat competition, PIs that care for safety don't make it far
- untrained personnel
- no proper supervision
- get out of jail cards for people like Patrick Harran, who called the 23 year old student who burned to death in his lab an experienced researcher doing independent research (or something along the same lines). I bet if she had found a cure for cancer, he would have called her "one of my students, working under very close personnel supervision".
- one person groups that don't have any expertise outside of an extremely narrow field. Industrial chemists can rely on a whole team of experts, but in academia, it is every man for himself.

Pre-mixing hydrogen and oxygen is so insane, it defies common sense.
I think this guy was the PI, someone with the name of Jian Yu is named in the lawsuit, and his bio matches pretty well:
"Jian Yu (PhD, Chemical Engineering, University of British Columbia, 1991), has over 24 years of experience in bio-based plastics, chemicals and fuels with an emphasis in chemical, biochemical and microbial conversion of renewable feedstock (e.g. agricultural residues, domestic wastes, and CO2/H2). Following his 3-year postdoctoral training in industry and academia, Dr. Yu spent 7 years at the Hong Kong University of Science and Technology and developed his teaching and research in biochemical and environmental engineering. Dr. Yu joined the University of Hawaii at Manoa in 2001 and participated in teaching and research in multiple programs including Marine Bioproducts Engineering, Ocean and Renewable Resource Engineering, and Molecular Bioscience and Bioengineering. With funding from the US Department of Energy, the Office of Naval Research, and private companies, he has developed active programs in bioplastics and biofuels. His current projects include: high grade drop-in liquid fuel from biomass syngas, a green refinery of CO2 and solar energy, and bioplastics from food processing wastes and lignocellulosic biomass."

PhD in chemical engineering and experience with CO/H2, syngas and biofules, but doesn't know that H2 and O2 don't mix.

A simple gas proportioner would have been all that was needed to make this experiment safe.

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