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Agent Stability Under Storage and Discharge Residue.


pdf icon Agent Stability Under Storage and Discharge Residue. (989 K)
Peacock, R. D.; Cleary, T. G.; Harris, R. H., Jr.

NIST SP 861; April 1994.

Evaluation of Alternative In-Flight Fire Suppressants for Full-Scale Testing in Simulated Aircraft Engine Nacelles and Dry Bays. Section 6, Grosshandler, W. L.; Gann, R. G.; Pitts, W. M., Editor(s)(s), 643-668 pp, 1994.

Available from:

Government Printing Office
Order number: SN003-003-03268-9

Keywords:

halons; residues; stability; storage; metals; experiments; halon 1301; infrared spectroscopy

Abstract:

Halon 1301 is known to be stable in metal containers for many years. Any by-products do not affect its fire suppression effectiveness or result in an unacceptable residue. For candidate replacement chemicals, comparable data are needed, reflecting the storage conditions of elevated temperature and pressure. Significant losses in fire suppression effectiveness and increases in toxicity are possible if the extinguishing agent degrades during storage. Thus, stability during the multi-year storage environment is an important concern. In this project, samples of each of the 12 candidate agents were evaluated in pressurized cylinders. It was presumed that NaHCO3 is stable under the likely storage temperatures and pressures. In order to allow for potential interactions analogous to actual storage conditions, a measured amount of metal (with separate tests for each candidate cylinder metal) was introduced into the containers prior to the experiments. The vessel and its contents were stored in an oven at elevated temperature for 28 days. After cooling to ambient conditions, an infrared spectrum of the aged sample was compared to a spectrum of the original sample. Degradation of the sample would be indicated by a systematic decrease in the absorbance of peaks attributable to the agent and/or the appearance of new peaks in the IR spectrum of the aged agent.