"The available regulatory framework now provides a solid basis for designing, building, and operating ships powered by methyl or ethyl alcohol," said DNV executive vice president Jan-Olaf Probst.

In addition to its class rules, DNV publishes updates to its document "Alternative Fuels for Containerships", which aims to provide neutral, fact-based, scientifically sound decision support for newbuilding projects.

The new chapter of the DNV Alternative Fuels document provides guidance on ship design arrangements, containment concepts, certification and training, signing a contract, and cost considerations.

"The requirements for methanol are much less complex than those for LNG," said Mr Probst.

"Methanol is non-cryogenic, liquid at ambient temperatures, and does not require refrigeration or specific and expensive materials for tanks and pipes. Appropriate storage and handling technologies and expertise exist, and bunkering would be comparatively easy to implement."

Methanol tanks may be integrated into the hull structure but require more space on board than Liquefied Natural Gas ( LNG) or Heavy Fuel Oil (HFO) for a given trading distance.

"In most current engines, methanol requires a pilot fuel for efficient burning, so diesel fuel must be carried on board as well, doubling as fallback fuel too," said Mr Probst.

Methanol is one of the top five chemical commodities shipped worldwide.

Many factories produce large quantities from fossil sources for use in many industrial applications.