Source: http://cen.acs.org/articles/94/web/2016/04/Spark-pressure-gauge-caused-University.html
An explosion last month caused a University of Hawaii, Manoa, postdoctoral researcher to lose an arm. The explosion was caused by a spark from a digital pressure gauge that was not designed for use with flammable gases, says a Honolulu Fire Department report.
The postdoctoral researcher was combining hydrogen, carbon dioxide, and oxygen gases from high-pressure cylinders into a lower pressure tank when the incident occurred.The gas mixture was “food” for bacteria being used to produce biofuels and bioplastics. The gas gauge identified in the research paper was an “intrinsically safe” model designed to prevent ignition.
But after postdoctoral researcher started in the lab last fall, she purchased a 49-L steel gas tank, a different gauge not rated as intrinsically safe, a pressure-relief valve, and fittings, and she put them together. She was using a mixture of 70% hydrogen, 25% oxygen, and 5% carbon dioxide for her experiments, the report says.
On the day of the incident, the 49-L tank exploded when the postdoctoral researcher pressed the off button on the gauge. “She did not lose consciousness or hit her head; she was aware that she lost her arm in the explosion,” the report says. “She couldn’t open the door to the lab, the door was stuck closed.” Security officers and a graduate student kicked in the door to the postdoctoral researcher get out. Her right arm was severed just above the elbow.
To prevent this type of accident occurring on your campus, only permit trained employees (not students) or gas providers to install gauges on compressed gas tanks.