Military folks on flight status are not permitted to wear to wear synthetics....cotton, wool, leather, and NOMEX (yes, I know that NOMEX doesn't grow on trees!) are the rule. There are frequent injuries due to melting synthetics (rubber, latex, nylon, etc) in waistbands and bra's burning the wearer in a flash fire, which is what nomex will protect you from.<br><br>I can speak to the military SRU-21 vest and the relative lack of utility of the components. Issued, it doesn't provide much in the line of supplies. I augmented mine significantly.<br><br>Jeff Anderson, M.D.<br>MAJ, MC, FS, USAR (ret)<br><br>Jeffery S. Anderson, M.D.<br><br>