ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Chrysene Chrysene (C18H12), a polycyclic aromatic hydrocarbon (PAH) Originally from the CUAHSI HIS VariableNameCV. See: http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=VariableNameCV.