All of the following are advantages of using chemical agents for terrorist activities EXCEPT:

The correct answer highlights a crucial aspect of the operational challenges that terrorists may face when employing chemical agents. While chemical agents do offer several tactical advantages, such as silent deployment, surprise effects, and the capability to impact wide areas, these benefits come with significant risks, particularly to the terrorists themselves.

Deployment of chemical agents can indeed be hazardous to the individuals attempting to use them. Many chemical agents can pose immediate health risks, including toxicity, the potential for accidental exposure, and the challenges associated with handling and dispersal. This aspect emphasizes that while the usage of such agents can maximize their intended impact on targets, the terrorists must also navigate the inherent dangers involved in their use, which could compromise their ability to execute their plans effectively.

In contrast, the other options illustrate the strategic advantages that chemical agents can offer; for instance, silent deployment enables these agents to be used without immediate detection, leading to a surprise effect that can maximize psychological impact and casualties. Additionally, a wide area impact can result in broader devastation, amplifying the terror effect on a larger scale. Understanding these dynamics is vital for emergency responders to anticipate and react to possible scenarios involving chemical agents in terrorism.