Safety of confined spaces – A feasibility study for data-driven decision making

Dr Olanrewaju O Okunribido MSc, PhD, MCIEHF, C. ErgHF, MIMechE, CEn

Health and Safety Executive

Confined space incidents continue to be leading sources of multiple fatalities in industry in Great Britain and around the world. Generally, a confined workspace is an enclosure that is not designed for continuous occupancy, is large enough for occupation by a whole person or persons, is large enough for the occupants to perform the assigned work and has limited or restricted means of entry or exit. Existing evidence about confined space accidents in the scientific literature and accident reports and investigation data held by the Health and Safety Executive (HSE) were reviewed to gain insights into the usefulness of the HSE datasets for identifying root causes of these accidents and any other factors that may affect data-driven safety decisions about work in confined spaces. 

A better understanding of incident root causes and the effectiveness of risk control methods would better enable industry to target improvements and reduce harm. One way to improve this understanding may be a more data-driven analysis to gain insight as to where and how confined space hazards are present. Lloyd’s Register Foundation commissioned HSE to undertake a feasibility study to establish the viability of using available datasets about confined space work accidents to improve insights into confined space hazards. 

Aims and objectives

The aim of the study was to investigate the utility of the data available to HSE to gain insight into confined space incidents in the following ways: 

  • Understand the conditions that lead to incidents; 
  • Understand which sectors and locations experience the most incidents; 
  • Identify mitigating measures that could be taken to reduce risks associated with confined space entry and improve worker safety in them. 

There were five objectives 

  1. To establish the viability of the HSE data to provide the required insight into confined space incidents in GB. 
  2. To gain deep insight about the occurrence, sector spread and geography of the types of incidents identified. 
  3. To understand key health and safety challenges concerning working in confined spaces. 
  4. To map and seek to understand current developments for safety of confined space working in GB (e.g. types and range of risk control systems). 
  5. To identify and study other databases and intervention approaches from around the world including identifying whether the information was capable of providing the required insight and/or augment the available GB data. 

Key findings

The HSE datasets provide useful insights into conditions that lead to confined space incidents, identify industry sectors and locations that experience these incidents, and help identify mitigating measures that could be taken to reduce risk and to improve worker safety in confined spaces. The HSE datasets do not provide the required deep insights to enable effective decisions to be made to improve worker safety in confined spaces.  



To make the datasets more useful for safe management of confined space risks: 

  • A functional definition of a confined workspace is needed, in terms of accessibility, frequency of occupation, and size. 
  • The role of accident reporting as a means of improving safety in workplaces should be emphasised to employers. 
  • Identifying incidents that occurred in locations meeting accepted definitions of confined workspaces needs to be simpler. 
  • The data need to be sufficiently comprehensive, i.e. the recorded details need to extend beyond identification of the immediate cause of the incident to latent issues that influenced the event. 

To make the data more comprehensive will ensure that an accurate record is produced and enable critical analysis of the information using advanced techniques such as data mining. Development of database and information sharing structures and procedures is needed if international collaboration for prevention of confined space accidents is to be realised.


If you would like to know more about this project or would like to know how you can get involved, please email