The reform of international investment agreements (hereinafter“IIAs”) in recent years is featured by the inclusion of general exceptions in order to protect the host countries’right to regulate. Judging from the awards rendered by arbitral tribunal in Eco Oro v. Colombia, the general exceptions do not function as a final safety valve to safeguard host countries’public policy space. The root cause lies in the obscure provisions and the failure of arbitral tribunal to define the legal character of general exceptions. Though considered to stem from GATT/WTO, general exceptions in IIAs are distinguished from their counterpart in text, objective and context, which lead to the difference in their interpretation and characterization. General exceptions in IIAs should be understood as carve-out instead of affirmative defense. The characterization of general exceptions as carve-out could provide greater policy space for host countries, clarify the relationship between exceptions and other treaty obligations and achieve sustainable development of international investment regime.