Gas cylinder storage at the University of Hawaii

When C&EN published my story about the fire department investigation into the explosion at the University of Hawaii (UH) that cost postdoc Thea Ekins-Coward one of her arms, we got many comments about whether or how the gas cylinders were secured. The fire department report and photos had little information about that issue. The University of California Center for Laboratory Safety (UCCLS) report released on July 1, however, devotes a section of its recommendations to how gas cylinder safety could be improved at UH.

Note that Honolulu is not at high risk for earthquakes–according to the U.S. Geological Survey, it’s roughly equivalent to Sacramento or Las Vegas. Consequently, things that Coastal California scientists might need to do, such as double-strapping cylinders, are not required. That said, there was still room to do better.

This group of ten cylinders, for example, which included hydrogen, carbon dioxide, helium, and carbon monoxide:

Credit: Honolulu Fire Department

Credit: Honolulu Fire Department

Was secured as:

Credit: UC Center for Laboratory Safety

Credit: UCCLS

Comments UCCLS:

The typical gas cylinder clamp with cloth strap is only designed to support a single cylinder. Thus, a cluster of ten cylinders should be in a dedicated gas rack. Second, only cylinders of similar size should be secured together. Securing large and small cylinders together results in one cylinder size being secured at the wrong height. (Technical report, page 9)

As for the two oxygen cylinders:

Credit: Honolulu Fire Department

Credit: Honolulu Fire Department

UCCLS says:

● Both oxygen cylinders were strapped to the biosafety cabinet with a safety strap as required by OSHA and CGA P-1. However, the safety straps of both cylinders loosened as a result of the force of the explosion. Although not required by HIOSH, chaining gas cylinders presents a safer option.
● One of the oxygen cylinders was open when the explosion occurred and vented its gas content into the laboratory. However, it did not cause an oxygen enriched fire which would have led to more damage and possibly cause the adjacent oxygen cylinder that was closed to vent through the CG-1 (Rupture disk) pressure relief device. (Technical report, page 30)

In another lab, UCCLS found this one, captioned “Gas cylinder attached to an adjustable shelf in a bookcase.” I don’t know which lab this was in, but judging from the mess on the floor and exposed insulation at the back, I’m guessing it was one of the labs adjacent to the one in which the explosion happened. The report notes that for two adjacent labs, cabinets were blown off the walls.

Credit: UCCLS

Credit: UCCLS

UCCLS’s overall guidance on gas cylinder storage and use (Recommendations report, pages 7 to 10):

  • Gas cylinders should be restrained by chains secured to a wall with Unistrut steel bars. In earthquake areas there should be two chains placed at ⅓ and ⅔ height on the cylinder.
  • Store unused cylinders with the valve protection cap in place, not uncapped or with a regulator.
  • Do not use Teflon tape on cylinder outlet valves.
  • Do not use leaking, aged regulators.
  • Support and label gas lines.
  • Do not use plastic tubing such as polyethylene for hydrogen gas, or metallic materials for oxygen systems.

Author: Jyllian Kemsley

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  1. 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?

  2. After reading this article I read a corresponding account in Science, “University of Hawaii Lab Explosion Caused by Inappropriate Gauge”, April 20, 2016.

    I was surprised that the group stored an explosive mixture of H2, CO, and O2 in a metal cylinder that was not shielded. Blaming an electronic gauge for the explosion begs the question. The lab should have never allowed a pressure vessel containing an explosive mixture of gasses to be in the open lab. If such a mixture was necessary, the container should have been properly isolated behind a blast barrier. The gauge was just the trigger.

    Based on the Science article, it is quite possible that no one was aware that they had created a bomb in the laboratory. Such practices were not allow in the chemical industry when I entered it 40 years ago. It seems that the university should take a very hard look at all of their laboratory practices.

  3. Jyllian, thank you for forwarding additional article. UCCLS made the same point that I was getting at. The route cause was actually the mixture of fuel and oxygen above the explosive limit in a cylinder. A number of ignition sources could set that off.