The Panama Canal Authority (ACP) announced on Wednesday that it will be requiring vessels with certain types of cargo to cool their main decks with water at particular points during their transits of the Canal.

The requirement, effective immediately and indefinitely, applies to crude oil tankers, product carriers, and chemical tankers with cargoes that have flashpoints of less than 18 degrees Celsius.

Vessels can use their on-board sprinkler systems or other means to deliver the water.

This measure is a safety procedure aimed at preventing the automatic activation of the ships’ pressure relief valves. It should be done between 10am and 4pm while the vessels are under way at the Gatun Lake or Gaillard Cut parts of the Canal system. It also applies when vessels are at anchor in Canal waters.

But it does not apply when a ship is in the vicinity of the locks or while Canal deckhands are on board.