SAFETY
New guidelines for using ammonia in maritime operations are expected imminently
FUEL F
rom December 2nd to December 6th 2024, the International Maritime Organisation’s (IMO)
Carriage of Cargoes and Containers subcommittee is expected to approve interim guidelines for using ammonia as an alternative fuel. These guidelines advise that ammonia be stored and refrigerated at atmospheric pressure. They also propose detection thresholds at 25 ppm in enclosed spaces, 110 ppm in secondary enclosures, and 220 ppm to trigger alarms and shutdowns. Additionally, ships should install ammonia treatment systems to manage potential leaks. However, these interim guidelines
for ammonia and other existing interim guidelines for other alternative fuels are still considered too broad by experts, as they cover only basic functional requirements and do not address the practical, real-world handling of the chemicals. For the industry to eff ectively and safely transition to ammonia or other alternative fuels like methanol, more detailed guidance from industry leaders with experience in detecting and preventing safety incidents with these substances is essential.
AN ALTERNATIVE Exploring regulation and safety when using ammonia and methanol to fuel the maritime Industry
MANAGING SIMILARLY CHALLENGING PROPERTIES Ammonia and methanol have their own particular safety challenges. For example, exposure to ammonia vapours can cause irritation and damage to the eyes, nose, throat, and lungs. In higher concentrations, ammonia can be fatal. Methanol is also toxic. It aff ects several organs as well as the central nervous system, which can lead to long-term damage or death. Methanol is readily absorbed by all routes of exposure, including the skin. In addition, both molecules
are fl ammable. Ammonia can be ignited between 14 Vol.-% (lower explosion limit, LEL) and 32.5 Vol.- % (upper explosion limit, UEL). Spontaneous ignition occurs at 630°C in the presence of suff icient oxygen. Methanol is a highly fl ammable gas and can be ignited at concentrations between 6 Vol.-% (LEL) and 50 Vol.-% (UEL). Spontaneous ignition occurs at 440°C, making the threshold lower than it is for ammonia. On top of that, both substances
have unique dispersible behaviours that are challenging for tight
environments like ships. Ammonia is typically lighter than air. However, humid conditions can lead to the formation of ammonia vapour. This vapour is heavier than air, causing it to sink. Methanol is slightly denser than air (32 versus 28 grams per mole). The vapour often follows the movement of air. But if methanol is warmer than the surrounding air, it will rise. If it is cooler, it sinks and accumulates near the ground. These are just some of the
properties to consider when looking at future regulations for safe handling of these hazmats in maritime environments. To ensure the safety of workers, the environment and property, by addressing these special safety challenges, appropriate protective systems must be planned and implemented, such as gas and fl ame detectors as well as personal protective equipment (PPE).
POSSIBLE DETECTION SOLUTIONS ON SHIPS With its decades of experience, Dräger, a leader in gas detection, off ers point gas detection as one tried and true method for sensing gas leaks. This technology focuses
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