IACS: Guidelines for Monitoring and Safety Functions of EGCS

The International Association of Classification Societies (IACS) issued guidelines for monitoring and safety functions of Exhaust Gas Cleaning Systems (EGCS) to ensure compliance with marine pollution regulations. These systems, also known as SOx scrubbers, are an alternative to using low-sulfur fuel and enable ships to meet the sulfur limits of 0.5% globally and 0.1% in Emission Control Areas (ECA). The guidelines focus on safeguarding ships in the event of an EGCS malfunction.

Exhaust Bypass:
An exhaust bypass system must be installed to allow engines to continue operating during EGCS malfunctions. If the EGCS is designed to operate dry without impacting engine function, the bypass can be omitted. Safety interlocks are required to prevent both bypass and uptake dampers from closing simultaneously. High back pressure should trigger automatic bypass operation.

Control and Monitoring:
The EGCS must include automatic control, monitoring, alarm systems, and safety features to ensure safe operations. Systems should remain functional even if a single component fails. A Failure Modes and Effects Analysis (FMEA) is required to verify the design’s safety, especially for integrated control systems. On unmanned ships, EGCS alarms and monitoring can be incorporated into centralized systems.

Safety Shutdown System:
A safety shutdown system must work independently of other control and alarm systems. Key requirements include:

Visual and audible alarms at control stations to indicate the cause of the shutdown.
Manual emergency shutdown controls at both local and remote stations.
Manual reset required for system restart after a shutdown.
Automatic shutdown triggered by specific critical conditions.

Monitored Parameters:
Essential parameters to monitor include exhaust gas temperature, pressure, water levels, chemical treatment fluid conditions, and EGCS operational states. Deviations from preset limits should activate alarms or shutdown systems as necessary.

These requirements will apply to ships contracted for construction starting January 1, 2026, as mandated by the International Association of Classification Societies (IACS).