CleanShipping Index

The Clean Shipping Index (CSI) is a voluntary Swedish non-profit rating system that scores vessels on environmental performance beyond regulatory minimums. Shipowners self-assess each ship against five parameters: CO2, NOx, SOx and particulate matter, plus chemicals and water-and-waste management, with 30 points per parameter for a 150-point maximum. Each registered vessel receives a CSI class of 1 to 5. Scores count only after third-party verification of the self-assessed data, and verified ships can earn port and fairway dues rebates at participating ports. Cargo owners and charterers use CSI scores to select cleaner tonnage, making the index a market-based pull toward lower-emission ships.