Section 4 - Procedures relating to the cleaning of cargo tanks, the discharge of residues, ballasting and deballasting
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Conventions - MARPOL - International Convention for the Prevention of Pollution from Ships - Annex II of MARPOL 73/78Regulations for the Control of Pollution by Noxious Liquid Substances in Bulk - Appendix 4 - Standard Format for the Procedures and Arrangements Manual - Section 4 - Procedures relating to the cleaning of cargo tanks, the discharge of residues, ballasting and deballasting

Section 4 - Procedures relating to the cleaning of cargo tanks, the discharge of residues, ballasting and deballasting

  4.1 This section contains operational procedures in respect of tank cleaning, ballast and slops handling which must be followed in order to ensure compliance with the requirements of Annex II.

  4.2 The following paragraphs outline the sequence of actions to be taken and contain the information essential to ensure that Noxious Liquid Substances are discharged without posing a threat of harm to the marine environment.

  4.3 Deleted

  4.4 The information necessary to establish the procedures for discharging the residue of the cargo, cleaning, ballasting and deballasting the tank, shall take into account the following:

  • .1 Category of substance

    The Category of the substance should be obtained from the relevant Certificate.

  • .2 Stripping efficiency of tank pumping system

    The contents of this section will depend on the design of the ship and whether it is a new ship or existing ship (See flow diagram and pumping/stripping requirements).

  • .3 Vessel within or outside Special Area

    This section shall contain instructions on whether the tank washings can be discharged into the sea within a special area (as defined in section 1.3) or outside a special area. The different requirements shall be made clear and will depend on the design and trade of the ship.

    No discharges into the sea of residues of Noxious Liquid Substances, or mixtures containing such substances, are allowed within the polar waters.

  • .4 Solidifying or High-Viscosity Substance

    The properties of the substance should be obtained from the shipping document.

  • .5 Persistent floaters with a viscosity equal to or greater than 50 mPaˇs at 20ēC and/or a melting point equal to or greater than 0ēC

    This section should contain instructions on how to deal with tank washings of substances identified by the presence of '16.2.7' in column 'o' of chapter 17 of the IBC Code and the latest version of the MEPC.2/Circular, when operating in the areas specified in regulation 13.9 of Annex II.

  • .6 Compatibility with slops containing other substances

    This section shall contain instructions on the permissible and non-permissible mixing of cargo slops. Reference should be made to compatibility guides.

  • .7 Discharge to reception facility

    This section shall identify those substances the residues of which are required to be prewashed and discharged to a reception facility.

  • .8 Discharging into the sea

    This section shall contain information on the factors to be considered in order to identify whether the residue/water mixtures are permitted to be discharged into the sea.

  • .9 Use of cleaning agents or additives

    This section shall contain information on the use and disposal of cleaning agents (e.g. solvents used for tank cleaning) and additives to tank washing water (e.g. detergents).

  • .10 Use of ventilation procedures for tank cleaning

    This section shall make reference to all substances suitable for the use of ventilation procedures.

  4.5 Having assessed the above information, the correct operational procedures to be followed should be identified using the instructions and flow diagram of section 5. Appropriate entries shall be made in the Cargo Record Book indicating the procedure adopted.


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