Industry Standard Update 128: Small craft LPG systems

Industry Standard Update 128: British Standard BS EN ISO 10239:2025 Small craft- Liquified petroleum gas (LPG) systems
Date issued: 9 May 2025

This Industry Standard Update (ISU) provides an overview of the key areas of change arising from the revised British Standard BS EN ISO 10239:2017 Small craft – Liquified petroleum gas (LPG) systems (ISO 10239:2014).

Introduction
During April 2025, BSI published a revised version of British Standard BS EN ISO 10239:2025 Small craft – Liquified petroleum gas (LPG) systems⁽¹⁾. This supersedes the previous edition published in November 2017, which is now withdrawn. The new standard came into effect on 30 April 2025. The following is a brief overview of the areas of significant change to the revised BS EN ISO 10239⁽²⁾.

General
There have been updates to some definitions, where wording and the numbering of definitions have been amended. There is a new definition for small craft – recreational boat or watercraft. Interior space has now become habitable space and shut-off valve has been amended to appliance shut-off valve to further differentiate it from the main shut-off valve.

Hose assemblies, covered in Section 6.3, now include a table with different manufacturing standards for flexible hoses, including their maximum operating pressure and application.

Section 7.5 covers unattended appliances and has been re-worded: it now states that appliances are either room-sealed or open-flued appliances with an integrated oxygen depletion sensor.

Meanwhile, 7.6 requires unattended appliances (such as water heaters, refrigerators and cabin heaters) installed in a bathroom or shower room to be room-sealed.

Location and installation of LPG cylinders, covered in Section 9, has been revised and makes reference to cylinders being installed in an enclosure that can be either a cylinder locker or cylinder housing. New sub-sections 9.2 Cylinder Lockers and 9.3 Cylinder Housing, along with reference to new illustrations in Annex E of the standard, clearly describe and illustrate the difference between lockers and housings and where they can be used.

Ventilation requirements are in Section 10 and the wording has been updated, along with the formula used for calculating minimum sizing and the location of ventilation openings referenced to Annex B. The formula now includes allowance for open-flued appliances in the calculation.

LPG system commissioning labels are now a requirement in accordance with Section 12 (apart from air tightness testing), as previous versions of the standard have excluded commissioning/testing of the system and connected appliances with LPG.

The latest version of the standard does not include commissioning of the installed installation but it now requires a label to be attached near to the cylinder enclosure that states: “This installation has been installed in compliance with 10239 and air tested.

Prior to its first use, the LPG system should be commissioned by a competent person using relevant national codes and procedures appropriate to the country concerned. On completion of successful commissioning this label should be removed.”

Summary
This Industry Standard Update is an overview of the information contained in the amended standard. Gas Safe registered engineers/businesses should be aware that they have a responsibility to ensure that they are fully apprised of all the requirements of the whole published standard and their practical application.

Bibliography
⁽¹⁾ British Standard BS EN ISO 10239:2025 Small craft – Liquified petroleum gas (LPG) systems
⁽²⁾ British Standard BS EN ISO 10239:2017 Small craft – Liquified petroleum gas (LPG) systems
(ISO 10239:2014)