Guidance on permit-to-work systems
A guide for the petroleum, chemical and allied industries
This is a free-to-download, web-friendly version of HSG250
(First edition, published 2005). This version has been adapted for online use from HSE’s current printed version.
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ISBN 978 0 7176 2943 5
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This book describes good practice in the use of permit-to-work systems, and will help operators using these systems to ensure risks have been reduced to a level as low as reasonably practicable.
It will be particularly useful to the onshore and offshore petroleum industry, onshore chemical and allied industries and other industries. The potential for serious incidents in these industries is clear, and permit-to-work systems are a vital part of effective management of the hazards.
The book reinforces previous advice, and reflects recent technical advances (eg electronic permit systems) and good practice identified in these industries.
HSE Books
Page 1 of 40
© Crown copyright 2005
First published 2005
ISBN 978 0 7176 2943 5
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the prior written permission of the copyright owner.
Applications for reproduction should be made in writing to:
The Office of Public Sector Information, Information Policy Team, Kew, Richmond, Surrey TW9 4DU or e-mail:
[email protected]This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice.
Contents
Foreword 4
Introduction 5
How to use this document 6
What is a permit-to-work system? 7
When are permit-to-work systems required? 9
Essentials of permit-to-work systems 11
Display 11
Suspension 12
Permit interaction 13
Handover 13
Hand-back 13
Permit authorisation and supervision 14
Harmonising roles within permit-to-work systems 16
Responsibilities 17
Employers or duty holders 17
Site or installation managers (acting as originator, permit authoriser or area authority) 18
Contractors’ and subcontractors’ management (acting as performing authority or permit user) 18
Responsible authority (acting as permit authoriser, issuing authority or area authority) 19
Supervisory personnel (acting as performing authority or permit user) 20
Individuals (acting as permit user, site checker or isolating authority) 20
Training and competence 20
What does a permit-to-work look like? 22
Electronic permits 24
Work planning and risk assessment 25
Monitoring, audit and review of permit-to-work systems 27
Appendices 28
1 Relevant legal requirements 28
2 Further information on different permit types 30
3 Checklist for the assessment of permit-to-work systems 32
4 Permit-to-work monitoring checklist 36
References and further reading 38
Foreword
This guidance replaces the 1997 revision of Guidance on permit-to-work systems in the petroleum industry (ISBN 0 7176 1281 3) which took account of industry experience gained since 1991, and takes into account other relevant guidance, in particular The safe isolation of plant and equipment.1
This revision builds on previous editions by incorporating recent technical advances (eg electronic permit systems) and good practice identified in the onshore and offshore petroleum industry and onshore chemical and allied industries. It highlights key areas for possible future harmonisation of permit-to-work systems.
This document describes good practice in the use of permit-to-work systems, and as such may be useful to operators using permit-to-work systems as part of a demonstration that risks have been reduced to as low a level as reasonably practicable (ALARP). The guidance is applicable to the onshore and offshore petroleum industry, onshore chemical and allied industries and other industries where permit-to-work systems are used.
The document is primarily written around well-established paper-based permit-to- work systems, but where possible it accounts for the newer medium of electronic- based permit-to-work systems.
Introduction
1 The petroleum, chemical and allied industries store and process large quantities of hazardous substances including flammable and toxic materials, so the potential for serious incidents is clear. To prevent such incidents it is vital that there should be effective management of hazards, including the use of safe systems of work.
2 A permit-to-work system is an integral part of a safe system of work and can help to properly manage the wide range of activities which can take place close together in a small space, such as in a storage area or process plant.
3 When incidents do occur, human factors, such as failure to implement procedures properly, are often a cause. These failures may in turn be attributable to root causes such as a lack of training, instruction, communication or understanding of either the purpose or practical application of permit-to-work systems.
4 Permit-to-work systems form an essential part of the task risk assessment process. When a task is identified an appraisal should be carried out to identify the nature of the task and its associated hazards. Next, the risks associated with the task should be identified together with the necessary controls and precautions to mitigate the risks. The extent of the controls required will depend on the level of risk associated with the task and may include the need for a permit-to-work.
5 A permit-to-work is not simply permission to carry out a dangerous job. It is an essential part of a system which determines how that job can be carried out safely, and helps communicate this to those doing the job. It should not be regarded
as an easy way to eliminate hazard or reduce risk. The issue of a permit does not, by itself, make a job safe - that can only be achieved by those preparing for the work, those supervising the work and those carrying it out. In addition to the permit-to-work system, other precautions may need to be taken - eg process or electrical isolation, or access barriers - and these will need to be identified
in task risk assessments before any work is undertaken. The permit-to-work system should ensure that authorised and competent people have thought about foreseeable risks and that such risks are avoided by using suitable precautions. Those carrying out the job should think about and understand what they are doing to carry out their work safely, and take the necessary precautions for which they have been trained and made responsible.
How to use this document
6 This guidance is intended to provide a basic understanding of what is meant by a permit-to-work system. The advice is of a general nature, and is not intended to be exhaustive. It is essential that it is read in conjunction with the specific instructions and guidance produced by individual companies. In addition, the Task Risk Assessment2 and other guidance published by the Step Change in Safety initiative, and guidance published by the Health and Safety Executive (HSE) (see Further reading) should be consulted as appropriate.
7 This guidance is designed to assist in three basic ways:
■ to enable assessment of current permit-to-work systems against the principles put forward in this document, and to help to identify improvements to those systems in-line with current good practice;
■ to offer guidance on harmonisation of permit-to-work formats and terminology to assist people who regularly travel from site to site, from company to company, from refinery to offshore installation, and may have to work under several systems;
■ to allow development of a new permit-to-work system based on current good practice, and to give ongoing guidance through implementation and continued application.
8 This guide includes recommendations based on good practice from the petroleum, chemical and allied industries and learning from the investigation of incidents and accidents involving failures in permit-to-work systems. Some
case studies are highlighted in the text. In particular, readers are reminded of the importance of failures in the permit-to-work system in the sequence of events leading up to the Piper Alpha disaster in 1988, as summarised in the subsequent report by the Hon Lord Cullen.3
What is a permit-to-work system?
9 A permit-to-work system is a formal recorded process used to control work which is identified as potentially hazardous. It is also a means of communication between site/installation management, plant supervisors and operators and those who carry out the hazardous work. Essential features of permit-to-work systems are:
■ clear identification of who may authorise particular jobs (and any limits to their authority) and who is responsible for specifying the necessary precautions;
■ training and instruction in the issue, use and closure of permits;
■ monitoring and auditing to ensure that the system works as intended;
■ clear identification of the types of work considered hazardous;
■ clear and standardised identification of tasks, risk assessments, permitted task duration and supplemental or simultaneous activity and control measures.
10 The terms ‘permit-to-work’, ‘permit’ or ‘work permit’ refer to the paper or electronic certificate or form which is used as part of an overall system of work, and which has been devised by a company to meet its specific needs.
11 A permit-to-work system aims to ensure that proper consideration is given to the risks of a particular job or simultaneous activities at site. Whether it is manually or