National foreword

This Published Document is the UK implementation of CEN ISO/TS 18683:2026. It is identical to ISO/TS 18683:2021. It supersedes PD ISO/TS 18683:2021, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee GSE/38, Installation and equipment for LNG.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication is not to be regarded as a British Standard.

Compliance with a Published Document cannot confer immunity from legal obligations.

This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 November 2021.

This Technical Specification (CEN/TS) was approved by CEN on 25 November 2024 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

European foreword

The text of ISO/TS 18683:2021 has been prepared by Technical Committee ISO/TC 67 "Oil and gas industries including lower carbon energy” of the International Organization for Standardization (ISO) and has been taken over as CEN ISO/TS 18683:2026 by Technical Committee CEN/TC 282 “Refrigerated Liquefied Gases (RLG) SEVESO infrastructure design and operation” the secretariat of which is held by AFNOR.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

Any feedback and questions on this document should be directed to the users’ national standards body. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United Kingdom.

Endorsement notice

The text of ISO/TS 18683:2021 has been approved by CEN as CEN ISO/TS 18683:2026 without any modification.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 9, Liquefied natural gas installations and equipment.

This second edition cancels and replaces the first edition (ISO/TS 18683:2015), which has been technically revised.

The main changes are as follows:

title and scope restricted to Guidelines for safety and risk assessment of LNG fuel bunkering operations;
list of bunkering supply scenarios updated with experience gained since 2015 in Clause 4;
addition of concept of design stage risk assessment and operational risk assessment in 7.1;
addition of Quantitative Consequence Assessment in 7.2;
addition of roles and responsibilities of stakeholders in 7.3;
design requirements removed from Clause 8 to avoid duplication with ISO 20519;
individual Risk Criteria added in Annex A;
three methods added to determine safety zone in Annex B;
to avoid duplication with ISO 20519, the following clauses and annexes have been removed:
- Clause 9 Requirements to components and systems;
- Clause 11 Requirements for documentation;
- Annex C Functional requirements;
- Annex D Sample Ship supplier checklist;
- Annex E Sample LNG delivery note;
- Annex F Arrangement and types of presenting connection;
- Annex G Dry disconnect coupling.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

The properties, characteristics, and behaviour of LNG differ significantly from conventional marine fuels, such as heavy fuel oils and distillate fuels as marine diesel oil (MDO) or marine gas oil (MGO).

For these reasons, it is essential that all LNG bunkering operations are undertaken with diligence and due attention is paid to prevent leakage of LNG liquid or vapour and to control all sources of ignition. Therefore, it is important that throughout the LNG bunkering chain, each element is carefully designed and has dedicated safety and operational procedures executed by trained personnel.

It is important that the basic requirements laid down in this document are understood and applied to each operation in order to ensure the safe, secure, and efficient transfer of LNG as a fuel to the ship.

The objective of this document is to provide guidance for the risk assessment of LNG fuel bunkering operations and thereby ensuring that an LNG fuelled vessel and bunkering supply facilities are operating with a high level of safety, integrity, and reliability regardless of the type of bunkering supply scenario.

The LNG bunkering interface comprises the area of LNG transfer and includes manifold, valves, safety and security systems and other equipment, and the personnel involved in the LNG bunkering operations.

This document is based on the assumption that the receiving ships and LNG bunkering supply facilities are designed according to the relevant and applicable codes, regulations, and guidelines such as the International Maritime Organization (IMO), ISO, EN, and NFPA standards and the Society for Gas as a Marine Fuel (SGMF) and other recognized documents during LNG bunkering. Relevant publications by these and other organizations are listed in the Bibliography.

This document should be combined with the requirements set on ISO 20519.

In cases where the distance to third parties is too close and the risk exceeds acceptance criteria, the bunkering location should not to be considered.

1 Scope

This document gives guidance on the risk-based approach to follow for the design and operation of the LNG bunker transfer system, including the interface between the LNG bunkering supply facilities and receiving LNG fuelled vessels.

This document provides requirements and recommendations for the development of a bunkering site and facility and the LNG bunker transfer system, providing the minimum functional requirements qualified by a structured risk assessment approach taking into consideration LNG properties and behaviour, simultaneous operations and all parties involved in the operation.

This document is applicable to bunkering of both seagoing and inland trading vessels. It covers LNG bunkering from shore or ship, mobile to ship and ship to ship LNG supply scenarios, as described in Clause 4.

2 Normative references

3 Terms, definitions and abbreviated terms

3.1 Terms and definitions

3.2 Abbreviated terms

4 Bunkering supply scenarios

5 Properties and behaviour of LNG

5.1 General

5.2 Description and hazards of LNG

5.3 Potential hazardous situations associated with LNG bunker transfer

5.4 Composition of LNG as a bunker fuel

6 Safety

6.1 Objectives

6.2 General safety principles

6.3 Approach

7 Risk assessment

7.1 General

7.2 Types of risk assessment

7.3 Roles and responsibilities of stakeholders

7.4 Approach, scope and basis

7.5 Mitigation measures

7.6 Reporting

7.7 Safety Zone and controlled areas

7.8 Safety zone determination

7.9 Determination of monitoring and security areas

7.10 Simultaneous Operations (SIMOPs)

8 Functional requirements for LNG bunker transfer system

8.1 General

8.2 Functional requirements

9 Training

Bibliography

PD CEN ISO/TS 18683:2026

Guidelines for safety and risk assessment of LNG fuel bunkering operations

Current

Published:

31 Mar 2026