Less than 0.5 PSI. Generally considered to be insufficient to break out windows in normally encountered trans- and post-flashover compartment fires which do not classify as explosions.
Fang, J., and N. Breese, National Bureau of Standards. Fire Development in Basement Rooms, NBSIR 80-2120. Washington, DC: U.S. Department of Commerce, October 1980
Harris, R. J. The Investigation and Control of Gas Explosions in Buildings and Heating Plants. London and New York: E&FN Spoon, Ltd., 1983.
Skelly, M. J. An Experimental Investigation of Glass Breakage in Compartment Fires, NIST-GCR-90-578, 1990.
Pat Kennedy, CFEI, CFPS, MIFireE
Fire and Explosion Analyst
Sarasota, Florida
[
www.kennedy-fire.com]