For projects that have already been approved, decisions on project cost overruns are necessary if additional financing would cause the total expenditures for the project to exceed US $500,000. Overruns which do not cause total expenditures to exceed $500,000 can be approved within the context of a work programme or work programme amendment. The Executive Committee can approve modifications of approved project budgets with a total incremental cost exceeding US $500,000.
(UNEP/OzL.Pro/ExCom/8/29 Annex III, para. 3.11).