kSIST FprEN ISO 6338-4:2026

• Abstract:

  This document provides the part of the method to calculate the GHG emissions throughout the; LNG chain specific to shipping.; The general requirements are covered in ISO 6338-1.

• Status: Not Published
• Public Enquiry End Date: 01-May-2026
• ICS: 13.020.40 - Pollution, pollution control and conservation
• ICS: 75.020 - Extraction and processing of petroleum and natural gas
• Technical Committee: DPL - Gas supply
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 02-Nov-2026
• Due Date: 21-Dec-2026
• Ref Project: FprEN ISO 6338-4 - Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain - Part 4: Shipping (ISO/FDIS 6338-4:2026)

kSIST FprEN ISO 6338-4:2026 is a SIST draft standard for calculating greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain, focused on shipping. It sets the shipping-specific part of the LNG GHG method and points users to ISO 6338-1 for the general rules.

What does kSIST FprEN ISO 6338-4:2026 specify?

kSIST FprEN ISO 6338-4:2026 specifies how to calculate GHG emissions for LNG shipping within the wider LNG chain. The scope is limited to shipping, while the general method, reporting framework and common rules come from ISO 6338-1.

The document is organized into nine clauses:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 4 Principles
• Clause 5 GHG inventory boundaries
• Clause 6 Quantification of GHG emissions
• Clause 7 GHG inventory quality management
• Clause 8 GHG reporting
• Clause 9 Independent review

Clause 5 and Clause 6 do most of the technical work. Clause 5 defines what activities belong in the shipping inventory, and Clause 6 gives the source-by-source approach for quantifying emissions.

What are the key requirements of kSIST FprEN ISO 6338-4:2026?

kSIST FprEN ISO 6338-4:2026 requires the GHG report for LNG shipping to cover all associated activities within the shipping boundary. The report is prepared for each ship, over a defined period, and can then be allocated to cargo, including the ballast leg. In practice, this means operators need ship-level data before they can build cargo-level GHG figures.

Inventory boundaries and scope

Clause 5 says the inventory shall cover all associated shipping activities. Table 1 identifies the main included activities such as combustion emissions, methane slip, fuel-cell emissions, venting, gas freeing or gassing up, planned ship-to-ship transfer, and tank pressure management or cargo conditioning. It also separates activities handled by other parts of ISO 6338, such as FLNG and regasification vessels.

Emission source categories

Clause 6.1 groups emissions by source: combustion, fuel cells, venting, fugitive emissions, and imported energy, utilities and consumables. This structure matters because the operator has to collect different kinds of data for each source instead of applying one single factor to the whole ship.

Combustion and fuel cells

Clause 6.1.2 and Table 2 cover combustion sources such as gas combustion units, internal combustion engines, inert gas generators, gas turbines, boilers and incinerators. The document expects primary data where possible, combined with emission factors or measured emissions. It also says fuel production is not part of the shipping calculation, so the method is tank-to-wake rather than well-to-wake.

Clause 6.1.3 and Table 3 apply a similar approach to fuel cells. For both combustion and fuel cells, unburned hydrocarbons, including methane slip, are to be taken into account.

Venting and fugitive emissions

Clause 6.1.4 and Table 4 cover venting from purging, storage tank venting and pressure protection, with primary data for significant events and secondary data only for smaller contributions under the stated condition. Clause 6.1.5 and Table 5 cover fugitive emissions from leaks in pipes, fittings, valves, seals and gaskets. In practice, this means leakage can be estimated from equipment counts and standard factors, then refined with monitoring or LDAR campaigns.

Allocation, reporting and review

Clause 6.4 allocates all emissions to the LNG shipped and gives a method for spreading dry-dock or maintenance emissions across later cargoes. Clauses 7, 8 and 9 point back to ISO 6338-1 for quality management, reporting and independent review. That keeps shipping aligned with the rest of the LNG-chain method.

What terms does kSIST FprEN ISO 6338-4:2026 define?

kSIST FprEN ISO 6338-4:2026 uses the terms and definitions from ISO 14064-1 and ISO 6338-1. The following terms are central to reading the document:

• GHG - greenhouse gas, the emissions the method quantifies for the shipping part of the LNG chain.
• LNG - liquefied natural gas, the product being shipped and assessed.
• ballast leg - the voyage made without cargo, which may still be included in allocation.
• venting - the release of gas to atmosphere during purging, tank venting or pressure protection.
• fugitive emissions - unintended leaks from equipment such as pipes, valves, seals and gaskets.
• LDAR - leak detection and repair, a monitoring approach used to measure or adjust leakage factors.
• FLNG - floating liquefied natural gas, handled in another part of the ISO 6338 series.
• FSRU - floating storage and regasification unit, also handled outside this part.

Who uses kSIST FprEN ISO 6338-4:2026?

kSIST FprEN ISO 6338-4:2026 is used by LNG ship operators, GHG inventory teams, environmental managers, and organizations that need ship-level LNG emissions data. It also supports auditors, independent reviewers and receiving bodies that ask for quantified, reviewable shipping emissions.

In practice, users apply it to build GHG inventories, prepare reports, allocate emissions to cargoes, and document ship operations such as combustion, venting, leaks and maintenance-related emissions.

Which standards are used with kSIST FprEN ISO 6338-4:2026?

• ISO 6338-1 - provides the general principles, calculation rules, preferred units, allocation approach, quality management, reporting and independent review used throughout this part.
• ISO 14044 - supplies the life cycle assessment requirements and the cut-off criteria used when imported energy, utilities or consumables must be considered.
• ISO 14064-1 - provides the GHG terms and definitions used by this part.

What does the kSIST FprEN ISO 6338-4:2026 document contain?

kSIST FprEN ISO 6338-4:2026 contains a scope statement, references, terms, principles, inventory boundaries, calculation rules, quality management, reporting and review. Its technical core is in Clause 5 and Clause 6, supported by Tables 1 to 5.

Table 1 classifies ship activities as in scope or out of scope. Tables 2 to 5 set out the quantification approaches for combustion, fuel cells, venting and fugitive emissions.

Clause 6.4 gives the allocation approach, including how to spread emissions from maintenance, gassing up, cooling down and dry-docking over later cargoes. The final clauses link shipping emissions into the wider ISO 6338 process for quality management, reporting and independent review.

SLOVENSKI STANDARD
oSIST prEN ISO 6338-4:2026
01-april-2026
Izračuni emisij toplogrednih plinov v oskrbovalni verigi z utekočinjenim
zemeljskim plinom (LNG) - 4. del: Transport (ISO/DIS 6338-4:2026)
Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas
(LNG) chain - Part 4: Shipping (ISO/DIS 6338-4:2026)
Berechnungsverfahren der Treibhausgasemissionen (THG) in der gesamten
Flüssigerdgas-(LNG-)Kette - Teil 4: Transport (ISO/DIS 6338-4:2026)
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne gaz naturel liquéfié
(GNL) - Partie 4: Transport maritime (ISO/DIS 6338-4:2026)
Ta slovenski standard je istoveten z: prEN ISO 6338-4
ICS:
13.020.40 Onesnaževanje, nadzor nad Pollution, pollution control
onesnaževanjem in and conservation
ohranjanje
75.020 Pridobivanje in predelava Extraction and processing of
nafte in zemeljskega plina petroleum and natural gas
oSIST prEN ISO 6338-4:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 6338-4:2026
oSIST prEN ISO 6338-4:2026
DRAFT
International
Standard
ISO/DIS 6338-4
ISO/TC 67/SC 9
Calculations of greenhouse gas
Secretariat: AFNOR
(GHG) emissions throughout the
Voting begins on:
liquefied natural gas (LNG) chain —
2026-02-09
Part 4:
Voting terminates on:
2026-05-04
Shipping
ICS: 13.020.40; 75.020
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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RECIPIENTS OF THIS DRAFT ARE INVITED
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NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 6338-4:2026(en)
oSIST prEN ISO 6338-4:2026
DRAFT
ISO/DIS 6338-4:2026(en)
International
Standard
ISO/DIS 6338-4
ISO/TC 67/SC 9
Calculations of greenhouse gas
Secretariat: AFNOR
(GHG) emissions throughout the
Voting begins on:
liquefied natural gas (LNG) chain —
Part 4:
Voting terminates on:
Shipping
ICS: 13.020.40; 75.020
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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POTENTIAL TO BECOME STANDARDS TO
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or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
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RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 6338-4:2026(en)
ii
oSIST prEN ISO 6338-4:2026
ISO/DIS 6338-4:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles . 1
5 GHG inventory boundaries . 1
6 Quantification of GHG emissions . 2
6.1 Identification of GHG sources and quantification approach .2
6.1.1 General .2
6.1.2 Emissions from combustion .2
6.1.3 Emissions from fuel cells .3
6.1.4 Emissions from venting.3
6.1.5 Fugitive emissions .4
6.1.6 Emissions associated with imported energy, utilities, and consumables .4
6.2 Calculation of GHG emissions .4
6.3 Preferred units .4
6.4 Allocation .4
6.5 Carbon capture .4
7 GHG inventory quality management . 4
8 GHG reporting . 4
9 Independent review . . 5
Bibliography . 6

iii
oSIST prEN ISO 6338-4:2026
ISO/DIS 6338-4:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon
energy, Subcommittee SC 9, Production, transport and storage facilities for cryogenic liquefied gases.
A list of all parts in the ISO 6338 series can be found on the ISO website.
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.

iv
oSIST prEN ISO 6338-4:2026
ISO/DIS 6338-4:2026(en)
Introduction
Natural gas will play a key role in the energy transition (e.g. by replacing coal to produce electricity) and the
use of liquefied natural gas (LNG) to transport natural gas is expected to increase. The process of liquefying
natural gas is energy-intensive. Gas producers are increasingly accountable for their greenhouse gas (GHG)
emissions and the ambition to reduce them. Furthermore, there is an emerging marketing demand for GHG
data to enable commercial mechanisms such as offsetting to be utilized.
There is no standardized and auditable methodology to calculate the carbon footprint of the whole LNG
...