ABSTRACT
Modern weapons of mass destruction are nuclear, biological, or chemical weapons (CW) frequently referred to collectively as NBC weapons. What are weapons of mass destruction, they are chemical, biological, radiological and nuclear (CBRN) weapons that many countries have and would use as a means of defense or terrorism. CW is defined as weapons using the toxic properties of chemical substances rather than their explosive properties to produce physical or physiological effects on an enemy. CW includes such agents as mustard, tabun, sarin (GB), and nerve gas. VX gas is a V-type nerve gas. In the 1960s, considerable work went into developing CS gas as quick-acting, nonlethal tool for controlling riots and civil disorder. Later, a class of nonlethal, mental incapacitants that cause mental disorientation were developed, most notably BZ agents. Another point of vulnerability exists in building heating, ventilating, and air-conditioning (HVAC) systems. Building HVAC typically recirculates air from the occupied space to air-handling units and back again.
