FAQ: What is the general purpose criterion?
Article I of the BTWC defines a biological weapon by prohibited activities and purposes with respect to microbial or other biological agents, or toxins whatever their origin or method of production as well as to weapons, equipment or means of delivery designed to use such agents or toxins. This definition is not a list of prohibited items; instead it links the term ‘biological weapons’ to the purpose that the agents or toxins are intended for. If intended for hostile purposes, they qualify as biological weapons.
However, the very same agents and toxins, when intended for peaceful purposes (e.g., medicine and pharmaceutical research) and as long as their types and quantities are consistent with such permitted purposes, are entirely legitimate (handling them, on the other hand, may be subject to precautionary control measures).This tool for defining biological weapons based on intent is called the 'general purpose criterion'.