Marine Operations Note: 05/2026 - Carriage of Limited Amounts of Liquid Chemicals in Bulk for New and Existing Offshore Support Vessels (OSV)

(Supersedes: Marine Operations Note: 01/2021, Dated 22 March 2021)

Subject: Carriage of Limited Amounts of Liquid Chemicals in Bulk for New and Existing Offshore Support Vessels (OSV)

Ref: (a) Resolution MEPC.318(74)/Resolution MSC.460(101) – 2019 Amendments to The

International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code)

1. Resolution A.673(16) – 1989, Guidelines for the Transport and Handling of Limited Amounts of Hazardous and Noxious Liquid Substances in Bulk on Offshore Support Vessels (LHNS Guidelines) and Resolution MSC.236(82), Amendments to A.673(16)
2. Resolution A.1122(30) – 2017, Code for the Transport and Handling of Hazardous and Noxious Liquid Substances in Bulk on Offshore Support Vessels (OSV Chemical Code)

The following changes have been included:

1. The MON has been updated in general as the interim period has expired.
2. New guidance with regard to the application of the OSV Chemical Code has been added, along with specific guidance pertaining to Methanol.

Purpose

This Marine Operations Note provides information and practical guidance for shipowners, operators, and recognized organizations on the Liberian Administrations’ policy for the carriage of dangerous chemicals and noxious liquid substances in bulk on new and existing offshore support vessels (OSV). IMO has adopted Resolution A.1122(30) (OSV Chemical Code), which applies to OSVs the keels of which are laid or which, on or after 1 July 2018, are at the stage of construction and assembly has commenced as described in section 1.1.3 of the OSV Chemical Code. The amendments to the IBC Code adopted by Resolution MEPC.318(74)/Resolution MSC.460(101), which entered into force on 01 January 2021, also affect the substances new and existing OSV’s can carry.

This Administration has adopted policy concerning the carriage of substances on new OSV’s covered by the OSV Chemical Code and for existing OSV’s certified to carry substances under Resolution A.673(16) (LHNS Guidelines).

Background

Resolution MEPC.318(74)/Resolution MSC.460(101) amended the IBC Code and the carriage requirements for many dangerous chemicals and noxious liquid substances, including those contained in the LHNS Guidelines. The only cargoes not affected by the amendments are:

1. Oil-based and water-based muds containing mixtures of products listed in chapters 17 and 18 of the IBC Code and the MEPC.2/Circular and permitted to be carried under paragraph 1.2 of the LHNS Guidelines
2. Drilling Brines - Sodium Chloride Solution
3. Potassium Chloride Solution
4. Ethyl Alcohol
5. Acetic acid
6. Triethylene Glycol

All other cargoes are affected and have new, additional requirements in order to be carried.

The basic philosophy of Resolution A.1122(30) is to apply standards contained in the IBC Code and the IGC Code to the extent that is practicable and reasonable taking into account the unique design features and service characteristics of OSV’s. This resolution supersedes but doesn’t revoke Resolution A.673(16), as amended.

Operational Guidance

1. The Administration adopts and makes mandatory the OSV Chemical Code for OSV’s in accordance with Section 1.1, Application, of the code. OSV’s to which the code applies are to be surveyed and issued a Certificate of Fitness in the form shown in the code by an authorized Recognized Organization (RO).

With regard to Chapter 13 of the code, which states that, “For vessels carrying more than 1,200 m3 of cargoes with a flashpoint not exceeding 60°C or carrying cargoes emitting toxic vapours or gasses, the requirements for chemical tankers of SOLAS chapter III should apply”, the Administration provides the following clarification:

The application of this provision applies to vessels carrying:

i. more than 1,200 m3 of cargoes with a flashpoint not exceeding 60°C; or, ii. carrying any quantity of cargoes emitting toxic vapours or gasses.

iii. cargoes emitting toxic vapours or gasses refers to those products for which emergency escape respiratory protection is required in chapter 17 of the IBC Code (resolution MSC.4(48), as amended (column “n” indicates “Yes”)), or in chapter 19 of the IGC Code (resolution MSC.5(48), as amended (column “i” indicates “14.4 or 14.4.2)).

For example, this would exclude Methanol from this requirement as column “n” is indicated as “No” for this product.

1. For existing OSV’s previously carrying cargoes other than or in addition to those listed above, and which comply with Resolution A.673(16), as amended, the OSV can continue to carry those cargoes provided it is in compliance with the revised carriage requirements in Resolution MEPC.318(74)/Resolution MSC.460(101).

This includes cargoes that were not previously categorized as toxic but are in the revised carriage requirements, such as Methanol.

If you have any questions or require further information, please contact Regulations and Standards Department at RegsAndStandards@liscr.com or telephone +1 703 790 3434.

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