The Irish Public Health (Alcohol) Act and Public Health (Alcohol) (Labelling) Regulations require composition and health warning labels on all alcoholic beverages, including a warning that there is a direct link between alcohol and fatal cancers. In the WTO TBT Committee several Members have questioned the necessity of Ireland’s health warnings. The thrust of some interventions is that warnings are more trade restrictive than necessary because alcohol use does not cause cancer under all conditions, but only when drinking is “excessive”. If entertained in a dispute, this argument would place a WTO panel in the shoes of national regulators and extend WTO oversight through dispute settlement even deeper into national regulatory decision-making. A second argument raises questions about the relationship between WTO law and other international economic law. Some WTO Members have expressed concern that the Irish Regulations create a barrier to trade between EU Member States and therefore a barrier to international trade. Put simply, it has been suggested that the Irish Regulations create fragmentation within the EU internal market, which hinders the ability of non-EU WTO Members to trade with the EU as a bloc. Current discussions at the TBT Committee therefore raise fundamental questions about the functions of the WTO dispute settlement mechanism and the interaction between different bodies of international law.