While performing hydrogen gas release experimentation by thermally reacting a slurry of ammonia borane powder in silicone oil in a plug flow reactor, a discharge port on the test reactor became loose. A foaming white product was leaking from the fitting and discharging in the direction of the heat tape and insulation (back over the reactor). As a result, hot, reacting slurry flowed out of the port and was exposed to air. In the presence of oxygen, the slurry ignited, producing a green flame. A small green flame was noticed at the leak site and flaming product dripped onto the hood deck surface. The flame at the end of the reactor was ~10-12 inches tall at the highest point. The flame on the deck was ~4-6 inches in height.

The incident occurred behind the lowered sashes in the test hood. No one was injured. The hood was not damaged and the test equipment appears to be fully functional, except for a few thermocouple cables, heat tape, controller power cable and a section of polymer purge tubing that was in the path of the flame.

The building fire alarm was not pulled as the cognizant scientists determined the incident to be isolated, contained and that the fire could be extinguished with the equipment available. One researcher left the area to call for an emergency response while another researcher located the building fire extinguisher (<10ft away) and extinguished the fire with two short bursts. The sash was raised ~12 inches to aim the fire extinguisher discharge at the flame and was pulled back down after successfully suffocating the flame. The flames were extinguished within 15-20 seconds of ignition.