Research on mitigation of toxic threats is critical to national defense, but is often hazardous. Toxicity generally arises at the molecular level via reactions between toxins and host biomolecules. This lends itself well to simulations from which one may safely derive the insight required for effective preventative or therapeutic response strategies. Thus, in this paper we have applied quantum chemical methods to address toxicity arising from both hostile (i.e., nerve agents) and inadvertent (e.g., toxic industrial chemicals) sources. Neurotoxic reactions involving inhibition of the acetylcholinesterase enzyme have been structurally and energetically characterized with mind to mitigating the process. In a complementary effort, interactions between toxins and various catalytic and filtering media have been reported with an aim of improving chemical protection devices.