The contemporary growing investment in non-lethal weapons technology and the rapid advance in science and technology pose significant challenges to the object and purpose of the disarmament system based on the conventions on chemical and biological weapons. The paper discusses whether the present revolution in the life sciences might lead States to skirt the so-called General Purpose Criterion included in both the conventions, which assures a comprehensive approach towards biochemical disarmament. The issue of the use of riot control agents and incapacitants arises in this context. It is important to stress that they belong to different classes of agents: while the former are designed to produce local sensory irritant effects, the latter target the human nervous system and other physiological systems. The paper finally addresses the complex problem of the non-prohibited purposes under the CWC, by dealing with the following two questions: whether it is permissible to use riot control agents in a time of armed conflict and whether other chemical agents, apart from riot control agents, can be lawfully used for law enforcement. The analysis conducted here confirms the continuing relevance of legal interpretation in solving the ambiguities of the current non-proliferation debate: the conclusion is that incapacitating agents do not satisfy the qualitative and quantitative requirements for the purpose of ‘law enforcement’.