In negotiations on the Chemical Weapons Convention delegates have addressed the question of how to verify compliance with those provisions which relate to the production and non-production of relevant chemicals. In order to facilitate the work of the negotiators, the Pugwash movement and SIPRI gave a group of fourteen scientific and other experts on the negotiations the task of analysing how the current Convention provisions would be applied to a specific chemical, thiodiglycol. This chemical can be used as a precursor to the chemical warfare agent, mustard gas. In eleven chapters and an annexe, the authors present their individual findings, illustrated with tables and figures. The steering committee of the project have provided summaries in introductory and concluding chapters. The particular problems of monitoring thiodiglycol production outlined may serve as a model for monitoring other chemicals which will be covered by the future Chemical Weapons Convention.