The Honolulu Fire Department released Monday the investigation report into the cause and origin of a laboratory explosion at the University of Hawaii at Manoa.
The explosion occurred on March 16 in a Hawaii Natural Energy Institute biofuels research laboratory in the Pacific Ocean Science and Technology (POST) building.
A visiting researcher, identified in the report as Thea Ekins-Coward, was injured. The report confirms she lost an arm in the explosion.
According to the fire investigator, the explosion occurred in a portable gas cylinder:
The accidental cause of this explosion was caused by the detonation of compressed gasses to include: Hydrogen, Carbon Dioxide, and Oxygen within the air tank. A digital pressure gauge used to check the pressure within the tank was not rated or designed (not Intrinsically Safe) to be in a flammable gaseous atmosphere. When the OFF button was pressed, an electrical arc/spark created within the gauge detonated the flammable gas within the tank causing the explosion.
“There was a switch that produced the spark when it was operated, so putting together the source of ignition with the proximity of the fuel, that’s the conclusion that our investigators were able to determine,” said Terry Seelig, HFD battalion chief of the Fire Prevention Bureau.
HFD also says the equipment that contributed to the blast should not have been there in the first place.
Ekins-Coward provided a statement from the hospital that described what happened:
On this particular day, she moved and filled the tank with a set amount of gasses using the Ashcroft 300 psi digital gauge that is battery operated. This gauge is a push button type for ON and OFF. When she disconnected the hoses used to fill the tank, she checked the pressure in the tank to verify the amount to be 117 psi. She then pressed the OFF button and the tank exploded. Prior to the explosion, she did not hear any sounds of escaping or leaking gasses from any of the fittings or pressure relief valve.
She did not lose consciousness or hit her head; she was aware that she lost her arm in the explosion. She couldn’t open the door to the lab, the door was stuck closed. A person by the name of Savannah was there to help get the door open and help her out of the lab.
She added that earlier in the week, she was conducting another experiment using a smaller one gallon size air tank assembly nearly as identical as the one that failed using similar components to include the Ashcroft 100 digital pressure gauge and the premixed gasses. The tank pressure was set to 27 psi. After reading the gauge, she pressed the OFF button and a small internal explosion occurred. She related to me that there was evidence of a soot and smoke stains.
Static shock also appeared to have been a problem as Ms. Ekins-Coward would get shocked on occasion when touching the tank.
She brought this information to the attention of Mr. Yu who she said told her don’t worry about it.
“This was a wake-up call, not just for the University of Hawaii, but I think for laboratories across the country.”
The earlier, smaller incident was never reported because there are no safety protocols addressing that.
“Apparently, it was not of enough energy or significance to cause any damage or harm,” Seelig said.
But, Meisenzahl says, changes in the works: “I don’t want to speak out of turn here, but I imagine that it should have been reported.”
A team from the UC Center for Laboratory Safety is conducting an independent investigation, and Meisenzahl said “we will have a more comprehensive understanding once that is complete,” hopefully by the end of April.
“We’ve also requested that this organization, that once again is a national leader when it comes to lab safety, also has suggestions for us as far as more protocols that we can put into place,” he added.
Ekins-Coward said the tank’s assembly was designed by laboratory professor Jian Yu, Ph.D. In his statement, however, he said:
The tank that failed was Ms. Ekins-Coward’s design. She bought the equipment (tank, digital gauge, pressure relieve valve, and fittings) between November 2015 and January 2016. The tank was to have been rated at 10 bar or 150 psi. When the tank was assembled with its parts, a pressure test was done using the buildings air which produced 91.2 psi. Several leaks were detected. So the tank assembly was taken to the Universities maintenance for help in stopping the leaks.
The fire investigator also reported that the cover of the tank’s gauge went missing sometime between March 17-21 and has not been recovered, though UH says that hasn’t hindered its investigation.
University spokesman Dan Meisenzahl said at the press conference that the gauge cover “is probably somewhere in the lab” and he’s “confident that it will turn up.
“The lab, as you can imagine, is still in disarray, but they know what make and model the gauge is,” he added. “The question is whether that gauge was appropriate for that use.”
He said the biofuels research laboratory was inspected previous to the explosion in January and Ekins-Coward’s setup was completed in February.
Meisenzahl said following the explosion, the university’s Office of Environmental Health and Safety reviewed and surveyed all of the 500-plus laboratories on campus to ensure similar experiments weren’t being conducted elsewhere.
The university is also establishing a new chemical and physical safety committee with representatives from schools and colleges that conduct research to work with other safety-related committees and further strengthen protocols.
“This was a wake-up call, not just for the University of Hawaii, but I think for laboratories across the country,” Meisenzahl said.
As for how much UH is paying for the independent investigation, Meisenzahl said that information is not yet available.