How to handle an Exhaust Gas Cleaning System (EGCS) malfunction?

Hello Quesenians,

Do you know what actions need to be taken if the Exhaust Gas Cleaning System (EGCS) fails to meet the scrubber guidelines?


I understand that your question refers to the regulatory handling of a malfunction on the EGCS (SOx scrubber)

It is recommended to consult the MEPC.1 / Circ.883.(

In general, the below principles apply:

  1. Any EGCS malfunction must be recorded in the class approved EGCS record book.
    The EGCS operator should attempt to identify the root cause and repair the malfunction based on the instructions included in the Class-approved EGCS Technical Manual.

  2. Any EGS malfunction that lasts more than 1 hour or repetitive malfunctions, should be reported to Class and Flag. The report must include a rectification plan. The vessel will have to change over to compliant fuel. If there is not enough compliant fuel onboard, the operator will have to notify Class / Flag and the vessel will continue consuming high Sulphur fuel until the first convenient bunkering port. The submission of an action plan is necessary to get the approval.

  3. Short term exceedances and spikes of the SO2/CO2 ratio in transient operational conditions e.g. sudden M/E load changes, are acceptable and no further action is necessary. These conditions should be described in the EGCS Technical Manual.

  4. If a malfunction occurs in a single sensor of the monitoring systems (SO2/CO2 ration, PH, PAH, turbidity) then the vessel may keep using the EGCS without changing over to compliant fuel provided that:

  • data of the functioning monitoring sensors at the time of the malfunction are recorded in order to confirm that all other relevant data showing values in line with the values prior to the malfunction. If the other parameters are within the normal levels, this is an indication that there is only an instrumentation malfunction rather than non-compliance with regard to the levels allowed in the exhaust gas and the discharge water.
  • Sulphur content of the fuel oil used from the time when the malfunction started.
  • the defective sensor is replaced as soon as practicable.

You may also refer to the below flow diagram by DNV.