This document provides guidance on the Class and Statutory requirements for use of so-called ‘drop-in’ liquid biofuels for marine and offshore installations, for use as direct replacements of, or as blends with, conventional petroleum derived residual (RM-grade) or distillate (DM-grade) fuel oils. Such biofuels should comply with the ISO 8217 Petroleum products – Fuels (class F) – Specifications of marine fuels standard.

These guidance notes are applicable to ‘drop-in’ biofuels but not to the bio-derived gaseous fuels such as biomethane or liquid methyl/ethyl alcohol fuels that fall under the scope of IMO Resolution MSC.391(95) The International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels (IGF Code).