Article 234 UNCLOS

Article 234 of UNCLOS, the Arctic exception, lets coastal states adopt and enforce non-discriminatory laws to prevent and control marine pollution from vessels in ice-covered areas within the EEZ, where severe climate and ice for most of the year create obstructions or exceptional hazards to navigation. It is the legal basis Canada and Russia invoke for the Northwest Passage and Northern Sea Route regimes, and it complements the IMO Polar Code, which sets the binding ship-construction and operational standards for polar waters.