European Commission Guidelines on Methane Slip Factors

This document is a regulatory guide issued by the European Commission detailing the reporting and verification of actual tank-to-wake methane slip emission factors for marine diesel engines under the FuelEU Maritime Regulation. The guidelines integrate the IMO protocol of Resolution MEPC.402(83) for methane slip measurements and provide an interim procedure for engine load monitoring until international standards are established. The document outlines the significance of verified methane slip in reducing greenhouse gas emissions, particularly emphasizing the impact of methane slip on overall CO2-equivalent emissions. It describes the measurement protocols for methane slip, including acceptable methods for onboard and test-bed measurements, and provides two approaches for calculating actual methane slip based on gas fuel flow measurement or emission factors. Additionally, the guidelines specify documentation requirements for companies to utilize actual methane slip factors, including the preparation of a Methane File and annual reporting obligations to the FEUM Verifier.