An uncontrolled release of HN3 from spherical pressure tank was simulated to study the kinetics of the NH3 concn. changes in a water curtain as a function of time. The ay. water droplet diam. and the spraying spectrum were detd. by using a droplet spectrum analyzer. The tech. characteristics of turbines used in a com. vehicle of the fire brigade were taken into consideration. The largest NH3 concn. decrease (92.2%) was produced by stream of exhaust gases with the entrained air according to a diln. mechanism. The water spray currents generated by the vehicle were responsible only for 2.54% of the decrease of NH3 concn.