Field tests on human tolerance to (LNG) fire radiant heat exposure, and attenuation effects of clothing and other objects

The author exposed himself, in normal civilian clothing (of full sleeve cotton/polyester shirt and jean pants), to radiant heat from a LNG fire. The exposure was for several tens of seconds to heat flux levels ranging from 3.5 kW/m2 to 5+ kW/m2 (exposure times from 25 s to 97 s at average heat flux values in the 4 kW/m2 and 5 kW/m2range). Occasionally, he was exposed to (as high as) 7 kW/m2 for durations of several seconds. He did not suffer any unbearable or even severe pain nor did he experience blisters or burns or any other injury on the unprotected skin of his body. The incident heat fluxes on the author were measured by a hand-held radiometer (with digital display) as well as by strapped on wide-angle radiometers connected to a computer. He could withstand the US regulatory criterion of 5 kW/m2 (for 30 s) without suffering any damage or burns. Temperature measured on author's skin covered by clothing did not rise above the normal body temperature even after 200 s of exposure to 4 kW/m2 average heat flux.