A small hydrogen fire occurred in a chemical process hood. A chemist was performing an experiment reacting manganese dioxide with hydrogen to produce manganese oxide and water. The chemist had left the process, which would take approximately one hour to complete, and was working in a nearby lab. While the chemist was gone, a second worker heard a pop, saw the hydrogen fire in the hood, and requested the activation of a fire alarm. A third employee in the area activated a manual fire alarm. The chemist, upon hearing the fire alarm, returned to the room, shut off the hydrogen fuel supply, and evacuated the facility. The hydrogen fire lasted for approximately one minute. The remaining small fire was extinguished about 10 minutes later with a HALON portable fire extinguisher by a radiological control technician (RCT) assigned to the area when he entered to survey the room. The glass front on the hood was cracked, and except for the damage done to the glass column and equipment used in the process, there was no other damage.
The direct cause for this occurrence involved an equipment/material problem, defective or failed part. The glassware column used in the chemical reduction process failed. A hole developed in the side of the glassware column that allowed hydrogen to escape and be ignited by the heat tape wrapped around the glass tube. Due to the glass fire involvement, it could not be determined if the glassware column had failed or if the heat tape failed and created a hot spot which eventually caused a hole to develop in the glassware column. However, the glassware column that failed was used previously to perform this same process.
Laboratory accidents can happen despite the best preparation and careful attention to procedures. However, the lesson to be learned here is that employees must always be sure they understand the hazards of the activities, and that they know how to respond to emergencies. This is accomplished through on-going training in emergency procedures, and in understanding the procedures and equipment.