National foreword

This British Standard is the UK implementation of EN 17975:2025.

The UK participation in its preparation was entrusted to Technical Committee DS/1, Dependability.

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.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2025.

This European Standard was approved by CEN on 7 April 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

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

This document (EN 17975:2025) has been prepared by Technical Committee CEN/TC 319 “Maintenance”, the secretariat of which is held by UNI.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2025, and conflicting national standards shall be withdrawn at the latest by December 2025.

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 organisations of the following countries are bound to implement this European Standard: 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.

Introduction

Many occupational accidents are caused by a failure to manage energy & fluid sources during maintenance activities and can result in serious impact on people, assets, and activities.

This standard is concerned with occupational safety and how to best control the risks related to energies & fluids linked to maintenance activities.

The safety and health of workers prior to, and during, maintenance tasks on items involves a series of practices and procedures aimed at controlling all energy & fluid sources. These practices and procedures enable a worker to be sure that they can work on an item without any accidental reconnection of energies or fluids and avoid being exposed to a hazardous working environment.

Depending on the task, items and related risk analysis, the safety of workers is based on the individual or combined implementation of the following specific processes for each energy & fluid:

Reinforced Isolation by lockout/tagout of energies & fluids (RI);
Standard Isolation by lockout of energies & fluids (SI);
Neutralization of energies & fluids by the control systems (N);
Specific Provisions for activities involving energies & fluids (SP).

On its own, reinforced isolation by lockout/tagout of energies & fluids ensures the full protection of workers. However, the design of existing items or the type of operations does not always enable such an approach to be applied, which therefore imposes use of one of the three alternative processes set out below.

Various industrial sectors (for example: chemical, metallurgy, agrifood, energies & fluids production and power distribution) have adopted their own “energies & fluids lockout” terminologies. Each industry has defined a formal system for risk analysis and operating procedures for securing each of the energies & fluids it works with. Depending on the sector, the terms used for “energies & fluids lockout” include, but are not limited to:

reinforced lockout/tagout,
standard lockout/tagout,
lockout of released energies & fluids,
LOTO - Lock Out, Tag Out,
LOTOTO - Lock Out, Tag Out, Try Out (see OSHA 29 CFR 1910.147),
administrative lockout,
etc.

1 Scope

This document provides users with guidance that help manage risks related to energies & fluids during maintenance activities on items when in use. It is the responsibility of each employer, according to the terms commonly used in the company, to:

Set out the correlation between the processes described in this document and standard practices,
Define the roles and responsibilities of the people involved in the energies & fluids lockout process.

This document refers to concepts, definitions, rules, recommendations, and best practices taken from national and international documents (lockout/tagout – “administrative lockout” – Lockout/Tagout (LOTO) – Safe isolation) that cover activities to ensure the safety of workers with respect to energies & fluids.

This document deals with the prevention of energy & fluid (e.g. powders, gases, liquids, etc.) related risks; it is noted that some are covered by specific regulations or standards, such as the electrical risk. Environmental issues related to energies & fluids are not in the scope of this document. Danger associated with energies & fluids can be direct (e.g. contact, absorption, etc.) or indirect by reaction (e.g. mixing, heating, etc.). The scope includes all fluids because they can be intrinsically dangerous or become dangerous.

The recommendations given in this document have been drawn up with a view to ensure the safety and health of workers around hazardous energies & fluids, and situations when they are conducting actions related to maintenance, settings or changing formats, regardless of the type of activity.

The recommendations relate to activities carried out on items. They are applied before, during and after the operation to:

The energies & fluids supplied, contained, transported, or released by items, products,
Risks related to the presence of hazardous energies & fluids for the worker and the surrounding personal.

This document is a methodological guideline within the maintenance standards.

NOTE Particular cases such as risks of lack of presence of vital elements for the worker (e.g. breathable air) are in the scope but will not be detailed.

2 Normative references

3 Terms, definitions, and abbreviations

3.1 Terms and definitions related to items and activities

3.2 Terms and definitions related to energies & fluids lockout

3.3 Terms and definitions related to risks and hazardous phenomena

3.4 Terms and definitions related to organization

3.5 Terms and definitions related to people

3.6 Abbreviations

4 Links between securing energies & fluids and maintenance processes

4.1 Boundaries and interfaces

4.2 Place of securing energies & fluids within maintenance processes

4.3 Interactions with other safety mitigation in maintenance

4.4 Equipment design and modification

4.5 Relation to severe hazard and emergency response management

4.6 Boundaries between maintenance and operating activities

5 Risk analysis

5.1 General issue: Systematic risk analysis mindset

5.2 Risk analysis methodology when applied to maintenance tasks

5.3 Specificities of risk analyses related to energies & fluids within maintenance tasks

5.4 Sources of the main hazards to be considered (energies & fluids, products that are sources of dangerous phenomena)

5.5 Design and methodology for selecting an energies & fluids lockout process

5.6 Updating energies & fluids specific risk analysis

6 Energies & fluids safety processes

6.1 Energies & fluids lockout process

6.2 Lockout/Tagout and safety check

6.3 Compensatory measures and Specific Provisions

6.4 Securing steps

6.5 Specific features of “PARENT/CHILD” energies & fluids lockout

7 Organizational provisions

7.1 Organizational prerequisites

7.2 Organizational provisions

7.3 Quality rules related to energies & fluids lockout

7.4 Energies & fluids competences management and training

7.5 LOCKOUT Administration

7.6 Use of tags and locks

7.7 Specific features – Design and modification of equipment

7.8 Energies & fluids lockout device identification sheet

Bibliography

BS EN 17975:2025

Maintenance. Risk control processes of energies and fluids risks in maintenance activities. Guidance

Current

Published:

30 Jun 2025