IMO Sub-Committee on Pollution Prevention and Response

The 7th session of the IMO’s Sub-Committee on Pollution Prevention and Response (PPR) was held in London from 17 to 21 February 2020. PPR 7 finalized guidelines for Exhaust Gas Cleaning Systems (EGSC – scrubbers), developed a basis for work to determine the impact of EGCS discharge water on the environment, drafted regulations for prohibiting the use and carriage of HFO as fuel in the Arctic, and revised the guidance on ballast water system commissioning.

Relevant for ship owners and managers of cargo ships and passenger ships, and manufacturers of ballast water systems and scrubbers.

Meeting highlights

  • Revised guidance on ballast water system commissioning, and on sampling and analysis for trial use 
  • Controls on cybutryne in the AFS Convention
  • Finalization of 2020 EGCS guidelines, and basis for work to determine the effect of EGCS discharge water on the environment 
  • Draft regulations for prohibiting the use and carriage of HFO as fuel in the Arctic

Ballast water

The guidance for ballast water sampling and analysis at commissioning of ballast water management systems (BWM.2/Circ.70) was revised. The compliance testing is intended to confirm correct installation of the equipment, and indicative analysis will be necessary only for organism size classes ≥50 and ≥10‒<50 µm at discharge, leaving out the indicator microbes in the D-2 discharge standard. Sampling of uptake water will not be required but is recommended for evaluating the treatment process according to the revised guidance.

Two new indicative methods were agreed for inclusion in the guidance on ballast water sampling and analysis for trial use (BWM.2/Circ.42/Rev.1: CV6 staining for use on the organism size classes ≥50 and ≥10‒<50 µm; and second-generation ATP for use for total bacteria count). A reference to the detail method of MPN Dilution Culture + Motility was also included in the guidance and to the guidelines for type approval (BWM.2/Circ.61).

PPR agreed on a main concept for a draft standard for verification of a ballast water compliance monitoring system, but further work is required for finalizing a protocol. 

Include controls on cybutryne in the AFS (Anti-Fouling System) Convention

PPR agreed on amendments to Annex 1 to the AFS Convention on a ban to apply or re-apply anti-fouling systems containing cybutryne from 1 July 2022. All ships should remove or seal such anti-fouling systems, except fixed and floating platforms, FSUs and FPSOs constructed prior to 1 July 2022 and not dry-docked on or after that date; ships not engaged in international voyages; and/or ships of less than 400 gross tonnage engaged in international voyages, if accepted by the coastal State.

Two options for timing were proposed for decision by MEPC 75 in April 2020; either before 1 July 2027 or not later than 60 months following the last application of such an anti-fouling system prior to 1 July 2022.


PPR agreed on key elements forming the basis for further work on biofouling with focus on effectiveness and how to best implement the guideline. A Correspondence Group on the review of the Biofouling Guidelines was established under the leadership of Norway, to provide concrete recommendations to PPR 8.

Reduction of the impact on the Arctic of black carbon emissions from international shipping

PPR acknowledged a study concluding that fuel oil aromatic content is a key parameter for black carbon emissions. However, the sub-committee invited member organizations to conduct more research, and it was agreed to establish a Correspondence Group to PPR 8. 

Development of guidelines for onboard sampling of fuel oil intended to be used or carried for use on board a ship

PPR finalized the guidelines setting out uniform procedures for sampling the fuel oil carried for use on board a ship. The guidelines provide a method for PSC inspectors and clarifies for ship crews what to expect with regards to enforcement for the fuel oil carriage ban. 

Exhaust Gas Cleaning Systems

PPR agreed on revised guidelines for the approval and certification of Exhaust Gas Cleaning Systems (EGCS or scrubbers). The new guidelines will be applicable to systems installed on ships six months after adoption by MEPC 75 in April, i.e. most likely October/November 2020.

The major changes to the current guidelines are: a new definition for Polyaromatic Hydrocarbons (PAH) representing the oil discharges of the washwater; a higher frequency for the recording of washwater pH, PAH and turbidity; and a requirement that also EGCS approved under Scheme A require mandatory daily spot checks of the SO2/CO2 emission ratio.  

Additionally, PPR agreed that the guidelines should not specify that sulphur-compliant fuel oil should be used during survey under Scheme B, as a survey under Scheme B only covers the on-board monitoring equipment and the sulphur content of the fuel being used during the survey is irrelevant for testing the functionalities of the monitoring equipment.

Discharge of liquid effluents from EGCS

PPR drafted a scope of work for the evaluation and harmonization of rules and guidance on the discharge of liquid effluents from EGCS into waters. This scope of work will act as a basis for future studies to determine the effect of EGCS discharge water on the environment, in order to facilitate a uniform approach by local states for evaluating its effect and possible countermeasures.

Measures to reduce risks of use and carriage of heavy fuel oil as fuel by ships in Arctic waters

A draft text for a new MARPOL Annex I, reg. 43A, prohibiting the use and carriage of HFO as fuel in the Arctic from 1 July 2024 was agreed on, subject for approval by MEPC. For vessels complying with reg. 12A, fuel oil tank protection (e.g. double hull), the proposed entry into force date is 1 July 2029. There is also an option for states with an Arctic coastline to waive the requirement for ships flying its flag operating in its water until 1 July 2029.

Review of the IBTS Guidelines

To better reflect the current arrangements and operational procedures, the IBTS Guidelines and guidance for the recording of operations in the oil record book were revised. However, due to legal issues concerning whether bilge water may be evaporated or not, it was decided to forward the report to MEPC 76 for further consideration together with possible new submissions.

Record-keeping and measures to confirm the lifetime performance of sewage treatment plants

Concerns over inadequate sewage treatment plants have resulted in a need to revise Annex IV of MARPOL to ensure the lifetime performance of sewage treatment plants and a more robust regime for showing compliance, including record-keeping. A Correspondence Group was established to develop draft amendments to MARPOL Annex IV reporting to PPR 8. The target completion year is 2021.

Unified Interpretations of the NOx Technical Code

PPR 7 agreed on two unified interpretations by IACS (MPC 33 and MPC 74) which will be published as IMO Circulars. These UIs are related to on-board certification test for NOx and the necessary data to be submitted in the engine tests reports.

Safety and pollution hazards of chemicals and preparation of consequential amendments to the IBC Code

Two new products were assessed for inclusion in the MEPC.2 Circular. For a vessel fulfilling the carriage requirements, inclusion of the products will be made in the next Certificate of Fitness. 

Out of 42 cargo tank cleaning additives assessed at the meeting, only 23 were accepted for inclusion in Annex 10 of the next MEPC.2 Circular. Most of those additives rejected were not intended for the cleaning of NLS cargo residues.   

Corrected carriage requirement entries for Methyl Acrylate and Methyl Methacrylate, mistakenly omitted in the 2019 amendments of the IBC Code, will be included in list 1 of the MEPC.2 Circular and in a PPR.1 Circular.

Action plan to address marine plastic litter from ships

The work on marine plastic litter from ships continued with an agreement on two draft Circulars, subject to approval by MEPC 76 in October: one addressing provision of adequate reception facilities; and another on sharing results from research on marine plastic litter and encouraging studies to better understand microplastics from ships.

A Correspondence Group was tasked to consider how to amend MARPOL Annex V and propose options for such amendments and report to PPR 8 in 2021.

Standards for shipboard gasification of waste systems and use of multiple engine operational profiles for a marine diesel engine

Due to time constraints, these issues were not discussed by PPR and deferred to PPR 8 in 2021.


As PPR is a sub-committee, all decisions concerning rules, regulations and dates are subject to further consideration and approval by the Marine Environment Protection Committee (MEPC). DNV GL recommends our customers to monitor the outcome of MEPC 75 in April 2020.


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