FprEN ISO 6338-5

• Abstract:

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

• Status: Not Published
• Publication Date: 07-Mar-2027
• ICS: 13.020.40 - Pollution, pollution control and conservation
• ICS: 75.020 - Extraction and processing of petroleum and natural gas
• Technical Committee: CEN/TC 282 - Installation and equipment for LNG
• Drafting Committee: CEN/TC 282 - Installation and equipment for LNG
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 30-Sep-2026
• Due Date: 14-Jan-2028
• Completion Date: 30-Sep-2026
• Ref Project: oSIST prEN ISO 6338-5:2026 - Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain - Part 5: Regasification (ISO/DIS 6338-5:2026)

• Consolidated By: ISO/FDIS 6338-5 - Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain — Part 5: Regasification
• Effective Date: 12-Feb-2026

FprEN ISO 6338-5 is a CEN/ISO standard for calculating greenhouse gas (GHG) emissions in the liquefied natural gas (LNG) chain, focused on regasification. It specifies the regasification-specific part of the LNG emissions method for organizations that operate, control, report on, or review regasification plants. The general rules are in ISO 6338-1, which this part uses for the overall method, calculation framework, reporting, and review.

What does FprEN ISO 6338-5 specify?

FprEN ISO 6338-5 specifies the part of the LNG-chain GHG method that applies to regasification. Its scope runs from the inlet to the outlet of the regasification plant, so it is aimed at the plant boundary rather than the full LNG value chain.

The document is organized into scope, normative references, terms and definitions, principles, GHG inventory boundaries, quantification of GHG emissions, quality management, reporting, and independent review, followed by a bibliography. In practice, that structure helps a user move from boundary setting to emissions calculation, then to reporting and review.

What are the key requirements of FprEN ISO 6338-5?

FprEN ISO 6338-5 builds on ISO 6338-1 and adds the regasification-specific sources and boundary rules. The main job for the user is to identify every relevant facility and emission source at the regasification site, collect suitable activity data, and apply the shared method from Part 1.

GHG inventory boundaries

Clause 5 requires the GHG report for regasification to cover all associated facilities within the reporting boundary. The organization with financial and/or operational control over those facilities must report all emissions and removals, at least on an annual average basis. That matters because responsibility follows control, not just physical location.

Clause 5 also treats injection into the gas grid as done by the plant operator. For users, this avoids ambiguity when emissions accounting extends to the point where regasified gas enters the network.

Main regasification emission sources

Clause 6.2 groups emissions into fuel combustion, flaring and venting, fugitive emissions, and imported energy, utilities, and consumables. The document repeatedly points users toward primary data where possible, such as fuel use, fuel composition, flare gas data, utility quantities, and supplier emission intensity data.

For fuel combustion, Clause 6.2.2 covers gas turbines, diesel drivers, boilers, fired heaters, and incinerators. Unburned hydrocarbons are to be taken into account, so operators need to look beyond the fuel burner and include incomplete combustion effects.

Clause 6.2.3 covers venting and flaring, including atmospheric venting, flares, and nitrogen vents from NRU. The practical message is to capture the notable release points at the plant and to pair flare quantities with combustion efficiency data.

Clause 6.2.4 covers fugitive emissions from permeation and gas leaks. Typical practice is equipment counting with leakage factors, adjusted when monitoring data are available.

Clause 6.2.5 covers imported electric power, heat or steam, other utilities, and imported consumables. If supplier GHG data are not reliable, the calculation must account for the full supply chain of the imported commodity, with cut-off criteria aligned to ISO 14044.

Calculation, allocation, and assurance

Clause 6.3 sends the calculation method back to ISO 6338-1, and Clause 6.4 uses the preferred units in Part 1. Clause 6.5 requires emissions from regasification to be allocated to the energy forms produced or used in the process, such as heat, cold, and electricity; if downstream products or services are sold, the allocation method must be defined.

Clause 6.6 refers carbon capture to ISO 6338-1. Clauses 7 to 9 also defer quality management, reporting, and independent review to Part 1, so a user needs both documents for a complete inventory and assurance process.

What terms does FprEN ISO 6338-5 define?

FprEN ISO 6338-5 uses terms from ISO 14064-1 and ISO 6338-1. In the document, these abbreviations and terms are especially important:

• GHG - greenhouse gas, the emissions being calculated across the regasification boundary.
• LNG - liquefied natural gas, the material stored, shipped, and regasified.
• FSRU - floating storage and regasification unit, a floating facility that stores LNG and regasifies it.
• BOG - boil-off gas, vapor formed from LNG that must be managed in the plant.
• NRU - nitrogen rejection unit, a unit whose vents may contain methane and therefore need to be counted.
• Allocation - the assignment of emissions to outputs such as heat, cold, and electricity when more than one product or service is involved.

Who uses FprEN ISO 6338-5?

FprEN ISO 6338-5 is used by LNG regasification plant operators, FSRU operators, and organizations with financial or operational control over associated facilities. It also supports GHG inventory specialists, environmental reporting teams, engineers, buyers who need supplier emissions data, and independent reviewers.

In practice, they use it to set the boundary, collect activity data, quantify emissions, allocate shared emissions, and prepare GHG reports for regasification sites.

Which standards are used with FprEN ISO 6338-5?

• ISO 6338-1 - provides the general method, principles, calculation framework, preferred units, allocation approach, carbon capture treatment, quality management, reporting, and independent review.
• ISO 14044 - supports the life-cycle accounting logic and the cut-off criteria used when imported commodity data are incomplete or unreliable.
• ISO 14064-1 - supplies the general GHG terminology used with ISO 6338-1.

What does the FprEN ISO 6338-5 document contain?

FprEN ISO 6338-5 includes a typical regasification-plant figure and tables that map the main facility elements and emission sources in scope. The tables cover the approaches for fuel combustion, flaring and venting, fugitive emissions, imported energy, other utilities, and consumables.

The body also points readers to ISO 20257-1 and ISO 20257-2 for information on FSRU, and to ISO 6338-1 for the shared calculation, units, allocation, carbon capture, reporting, and review steps. That makes the document useful for operational inventories, design review, and third-party review of regasification emissions.

SLOVENSKI STANDARD
01-april-2026
Izračuni emisij toplogrednih plinov v oskrbovalni verigi z utekočinjenim
zemeljskim plinom (LNG) - 5. del: Ponovno uplinjanje (ISO/DIS 6338-5:2026)
Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas
(LNG) chain - Part 5: Regasification (ISO/DIS 6338-5:2026)
Berechnungsverfahren der Treibhausgasemissionen (THG) in der gesamten
Flüssigerdgas-(LNG-)Kette - Teil 5: Wiederverdampfung (ISO/DIS 6338-5:2026)
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne gaz naturel liquéfié
(GNL) - Partie 5: Regazéification (ISO/DIS 6338-5:2026)
Ta slovenski standard je istoveten z: prEN ISO 6338-5
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
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 6338-5
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 5:
Voting terminates on:
2026-05-04
Regasification
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne
gaz naturel liquéfié (GNL) —
Partie 5: Regazéification
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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Reference number
ISO/DIS 6338-5:2026(en)
DRAFT
ISO/DIS 6338-5:2026(en)
International
Standard
ISO/DIS 6338-5
ISO/TC 67/SC 9
Calculations of greenhouse gas
Secretariat: AFNOR
(GHG) emissions throughout the
Voting begins on:
liquefied natural gas (LNG) chain —
Part 5:
Voting terminates on:
Regasification
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne
gaz naturel liquéfié (GNL) —
Partie 5: Regazéification
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
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BE CONSIDERED IN THE LIGHT OF THEIR
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Published in Switzerland Reference number
ISO/DIS 6338-5:2026(en)
ii
ISO/DIS 6338-5:2026(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 General .2
6.2 Identification of GHG sources and quantification approach .3
6.2.1 General .3
6.2.2 Emissions from fuel combustion . .3
6.2.3 Emissions from flaring and venting .4
6.2.4 Fugitive emissions .4
6.2.5 Emissions associated with imported energy, utilities, and consumables .5
6.3 Calculation of GHG emissions .5
6.4 Preferred units .5
6.5 Allocation .6
6.6 Carbon capture .6
7 GHG inventory quality management . 6
8 GHG reporting . 6
9 Independent review . . 6
Bibliography . 7

iii
ISO/DIS 6338-5:2026(en)
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
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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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
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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, 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
ISO/DIS 6338-5:2026(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
chain (including but not limited to the well, upstream treatment, transportation, liquefaction, shipping,
regasification and end user distribution). Various standards indicate possible approaches but are
inconsistent in their results or not easily applicable.
The ISO 6338 series covers each part of the LNG chain and enables a consistent GHG inventory.
The KPIs and related requirements to access to key international initiatives, agreements and reporting/
accounting standards on climate ambitions and zero carbon emission strategies are given in ISO 6338-1:2024,
Annex B.
Attention should be paid to activities that can occur in different parts (e.g. gas treatment and distribution
upstream of the liquefaction plant).
NOTE It is not possible to make like-for-like comparisons, or define a certification scheme, for one block only.

v
DRAFT International Standard ISO/DIS 6338-5:2026(en)
Calculations of greenhouse gas (GHG) emissions throughout
the liquefied natural gas (LNG) chain —
Part 5:
Regasificatio
...