Roles for independent scientists in the formation of public policy on chemical weapons are specified by identifying different types of risk associated with chemical weapons and asking whether independent scientists could contribute usefully to their assessment and therefore to their management. Attention is paid to three sources of novel risk: the changing utility of chemical weapons; changing science and technology; and CW arms control. Having particular regard to the disappointing outcome of the April 2008 conference to review the operation of the Chemical Weapons Convention (CWC) and to the impending shift in the primary focus of the CWC oversight organization from disarmament to non-proliferation, twelve different roles are suggested. These include work on better implementation of the ‘general purpose criterion’, on expansion of the CWC Schedules, and on convergence of the Biological and Chemical Weapons Conventions.