The US Coast Guard has reopened the port of Morehead City two days after a chemical spill closed the North Carolina harbour.

CEO Thomas Eagar praised the first responders and the Coast Guard for their efforts to secure the area and ensure there were no casualties or damage to the environment.

The chemical PETN, or pentaerythritol tetranitrate, was spilled during a vessel operation at the port terminal.

PETN is described as the primary ingredient in detonating cords used for industrial explosions and also used in military devices and blasting caps.