There is no such thing as fireproof garment.  It is possible to make garments more ignition resistant but not fireproof. A flash fire is a very intense fire albeit short duration. Engulfment in a flash fire usually results in fatality no matter what the clothing is unless the fire size is small and the duration is very short. Typical heat fluxes from flash fires range from 170 to 270 kW/m^2 and really you need to estimate the duration of the exposure and from that the thermal "dose" and relate that to tables of typical damages.

Some references for you

Chang Y. C. et al., (2007) The Study of Flame Engulfment Protection of Firefighter's Clothing,  Feng Chia University, accessed online in June 10 at  http://140.134.132.124/bitstream/2377/3890/1/ce05atc902007000019.pdf

IChemE., 1989, Thermal Radiation: Calculation of Intensity from large fires.  First Report of the Major Hazards Assessment Panel, Thermal Radiation Working Group (Major Hazards Monograph) - IChemE

O’Sullivan, S. and  Jagger, S., (2004)  Human Vulnerability to Thermal Radiation Offshore , Health and Safety Laboratory, HSL/2004/04

Thanks Dr. Roth Phylaktou for your valuable inputs. By the word fire proof I wanted to mean ignition resistance, I completely agree with you on this. Another problem is these ignition resistance chemicals make the fabric hydrophobic in nature. We want the fabric hydrophilic for better comfort. Could you give any suggestion on this? Thanks Manas