A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured. Significant damage to the indoor facility also occurred.

A hydrogen leak originating from a tank within a high-pressure storage unit serving a hydrogen vehicle fueling station resulted in fire and explosion. Emergency responders were on scene within 7 minutes and contained the fire within 3hours. No damage was reported to the separate forecourt H2 dispenser or to other major station components within the station backcourt compound. No personnel injuries resulted directly from the fire and explosion -a nearby vehicle airbag triggered due to the explosion pressure, with minor injuries to the vehicle occupants.

A fire erupted from a tanker truck delivering liquid hydrogen to a factory. The ignition of leaking vapors created a plume of flames that rose dozens of feet into the air. The flames receded within seconds, leaving the truck with little damage and its driver unharmed.

The truck was off-loading hydrogen into a tank behind the plant when the incident occurred. The plant reported no delays in its production. It uses the hydrogen in various processes.

A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.

An employee noticed an unusual smell in a fuel cell laboratory. A shunt inside experimental equipment overheated and caused insulation on conductors to burn. Flames were approximately one inch high and very localized. The employee de-energized equipment and blew out the flames. No combustible material was in the vicinity of the experiment. The fire was contained within the fuel cell and resulted in no damage to equipment.

As a prerequisite to a storage tank slurry pump run, a tank operator identified a Lower Flammability Limit (LFL) Analyzer surveillance reading to the control room that was out of limits low. The reading was a negative zero % LFL indication (-0 % LFL). The tank operator roundsheet limits are 0 to 10% LFL. The "null" value (value read on analyzer when air with 0% LFL is drawn through the analyzer) as directed by the LFL Analyzer loop calibration procedure is set between 0 and 4% LFL.

A shop supervisor determined that a second shift would be necessary to complete some priority work on the spare hydrogen mitigation pump. The work scope for the shift would be dedicated to continued fabrication of designed tubing runs, repairs to existing tubing with known leaks and pressure testing of other various tubing runs. The shift craft complement would include three pipe fitters, one welder, one QC inspector and a shift supervisor.

An operator began preparations for a cleaning run, and was unaware that a maintenance task to calibrate a pressure transducer was scheduled to also take place that morning. The calibration required a break on a hydrogen line in order to install a Measuring and Test Equipment (M&TE) gage, which was used in the calibration. At the time the operator was informed of the calibration, the cleaning run procedure had been initiated but the actual cleaning had not yet begun.

A brazing retort in a shop malfunctioned and resulted in an explosion that propelled the retort shell to the roof of the brazing area and then back to the floor. There were no injuries but damage was sustained by the furnace housing and the retort shell.

Administrative personnel were soon on the scene to make a preliminary assessment of the situation. An expert safety team was retained to assist in the investigation of the explosion. The safety team conducted their initial field investigation on the afternoon of the explosion and again on the following day.

A subcontractor employee was using a band saw to cut a 1" metal pipe when a flash fire occurred on the third floor hydrogen fluoride area. Subcontractor employees were removing all piping associated with the Anhydrous Hydrofluoric Acid (AHF) system. These lines were being removed during plant decontamination and demolition (D&D). The subcontractor employee was attempting to cut a 90-degree elbow located at the highest elevation on the 1" line, but the lowest elevation of the overall piping run.