Vapour breakthrough behaviour of carbon tetrachloride - a simulant for chemical warfare agent on ASZMT carbon

ASZMT (Cu, Ag, Zn, Mo, TEDA impregnated) carbon was prepared by impregnation of active carbon with ammonical salts of Cu (II), Ag (I), Zn (II), Mo (VI) and TEDA using incipient wetness technique. Thereafter, ASZMT carbon was characterized using scanning electron microscopy, atomic absorption spectroscopy, thennogravimetry and surface characterization techniques. The ASZMT carbon was evaluated under dynamic conditions against carbon tetrachloride vapour that was used as a simulant for the persistent chemical warfare agents for testing breakthrough times of filter cartridges and canisters of gas masks in the National Approval Test of Respirators. The effect of carbon tetrachloride concentration, test flow rate, temperature and relative humidity on the breakthrough behaviour of the ASZMT carbon for CCl4 vapour has also been studied. The study clearly indicated that the ASZMT carbon provided adequate protection against carbon tetrachloride vapours. The breakthrough time decreased with the increase of the carbon tetrachloride concentration and flow rate. The variation in temperature and relative humidity did not significantly affect the breakthrough behaviour of ASZMT carbon at high vapour concentration of carbon tetrachloride whereas breakthrough time of ASZMT carbon reduced by an increase of relative humidity at low carbon tetrachloride vapour concentration.