Thermal Decomposition Products from Fire Suppression with HFC-227ea in an Electronic Facility

A study was undertaken to address concerns of corrosion in an electronic environment after fire suppression using HFC-227ea (C3F7H). Fire suppression using halocarbon agents, such as HFC-227ea, can produce thermal decomposition products, e.g., hydrogen fluoride (HF), which may cause corrosion in electronic equipment. In this study, full-scale experiments were conducted in a simulated electronic equipment room using six steel cabinets under various ventilation conditions. An in-cabinet cable fire was used in the tests as a fire source and HFC-227ea was used to suppress the fire. FTIR spectrometers were used to measure the gases in the cabinets and room. The test results showed that cabinet ventilation conditions affected fire extinguishment times in the cabinet, and therefore the amount of HF generation. In the open cabinet cable fire test, the concentration of HF was below 100 ppm in the fire cabinet. In the closed cabinet cable fire test, the maximum concentration of the HF reached 800 ppm in the fire cabinet. The migration of gaseous by-products from the fire cabinet to the adjacent non-fire cabinets was minimal. A large heptane pool fire test was also conducted in the simulated electronic equipment room; the maximum HF concentration in the room for this test reached 3900 ppm, slightly greater than the 3800 ppm within an open cabinet. However, peak HF concentrations of 1800 ppm and 500 ppm were observed within the ventilated and closed cabinets, respectively, during the heptane test.