Editors' Summary: Under the Maastricht Treaty, the nations that are members of the European Union (EU) together must develop common European environmental policies. Toward this end, the European Commission has proposed EU-wide environmental laws that are meant to harmonize the various and diverging environmental laws and policies of EU member states. The laws attempt to overcome the various trade, environmental, and sovereignty concerns of member states that are obstacles to environmental unification. To date, these laws exist in essentially two forms: Mandatory and voluntary. This Article attempts to discern the optimal form for such laws, in light of the expressed concerns of member states and the disciplines the General Agreement on Tariffs and Trade (GATT), including the GATT Agreement on Technical Barriers to Trade, imposes on such international laws. This Article discusses the mandatory EU Packaging and Packaging Waste Directive and the voluntary Eco-Management and Audit Scheme Regulation.