An important part of managing safety in the workplace is understanding how to respond to accidents and how to investigate them so businesses can stop them from reoccurring.

Those able to turn accidents into learnings will begin to combat the negative impact of the 36.8 billion working days lost each year through ill health and injury.

This article is an introduction to incident investigation, how non-complex incidents can be investigated effectively.


Rules and responsibilities

All employers must have a comprehensive accident investigation process in place.

Regulation 5 of the Management of Health and Safety at Work Regulations 1999 requires employers to plan, organize, control, and review health and safety. Investigations are essential to this process.

As well as investigating adverse events, organizations are legally required to report certain accidents to an enforcing authority (like the HSE or a local authority). This is required by the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR).

The Woolf Reforms also demand full disclosure of the circumstances of an accident to any injured parties considering legal action.

Investigating an accident and taking action to prevent it from happening again demonstrates an organization has a positive attitude to health and safety. Not only this, but the findings of an investigation provide essential information for insurers in the event of a claim.


Gathering information

Following an accident, the first thing to do is to take any emergency actions necessary like providing first aid and controlling any potential secondary events (like explosions and fires).

After this, the evidence should be identified, and the scene preserved as best as possible. Depending on the severity of the event, this may require work to be stopped and barriers put in place to prevent people from tampering with the scene.

The event should be reported to the person responsible for health and safety in the organization, who can decide on any further action required.

Direct observation of the scene, premises, workplace, environmental conditions, equipment, materials, and injuries can provide a range of useful information about what happened. Recording the scene can be done through photographs, sketches, and any notes.

You will need to identify and interview key individuals, including the injured party, witnesses and the health and safety manager responsible for the site.

Interviews should be used to gather contextual details – including dates, times, names, and job titles of those involved – plus in-depth accounts of the steps leading to the incident. By conducting multiple interviews, businesses can limit inaccuracies and biases.

In addition to interviews, assessments should be conducted in the site or environment in which the incident occurred – including inventories and details of the condition of equipment, buildings and any materials uniquely related to the accident.


Analyzing information

An investigation team must clearly identify the sequence of events and conditions that led up to and caused the accident.

The “why” method is a useful tool for organizing your findings and establishing what happened. This method involves taking the incident and constantly asking ‘why’ it happened, until the answer is no longer meaningful.

When completing an investigation, it may be that some accidents were caused by actions of a specific worker or set of workers. Errors of this nature are called human failings and can be influenced by some of the following:

  • Job factors like how much attention is needed to complete a task, and how much time has been allocated to it.
  • Human factors, including a worker’s physical ability and competence.
  • Organizational factors, like work pressure and quality of supervision
  • Equipment factors, including how easy a machine is to operate and the safety features it has.
  • Slips which happen when a person is carrying out familiar tasks automatically and unintentionally takes an action outside of the norm, like operating the wrong switch on a control panel.


It may seem like an easy solution to blame errors on the employees as a human failing. However, doing so is counter-productive and may alienate workers and, in turn, undermine its safety culture.

Instead, you should ask those involved to explain why they acted as they did without prejudice or comment. This will help better understand the reasons behind the immediate causes and potentially reveal additional underlying causes.


Identify suitable risk control measures

While analyzing the information gathered, several risk control measures might be identified as having failed. In these cases, it may be useful to refer to relevant standards, like the HSE or industry bodies, to establish if any of the measures recommended within them were not implemented and, if so, whether they should be.

At this point, these measures should be collated along with any other possible measures that could address the immediate, underlying and root causes of the event. Some measures will be more difficult to implement than others, but this should not prevent them from being listed at this stage.

Some risk control measures are more effective and reliable than others so, when assessing these measures, they should be considered in the following order:

  • Measures that eliminate the risk, like replacing a hazardous substance with a safer one
  • Measures that combat the risk at its source, like installing a guard around a saw blade
  • Measures that rely on human behavior, like providing personal protective equipment


Creating an action plan

After identifying potential risk control measures, and determining which of them should be implemented, an action plan can be created. To help determine which measures are high priority, consider factors like what is essential and what cannot be left until another day. Also, think about how high the risks are to employees if control measures are not completed immediately.

Those risk control measures that do not control high priority risks must be put in the action plan in order of priority and have a timescale and person responsible for their implementation assigned to them.

The objectives of an action plan must deal effectively with the immediate, underlying and root causes of the adverse event, and be SMART (specific, measurable, agreed. Realistic and time-bound).


Regular reviews

A business’ responsibility does not end when these measures are rolled out. Check-ups must be scheduled, including inspections of the environment and equipment, in line with the report recommendations and key health and safety advice. Those in charge of health and safety should receive regular training to keep them up to date with new health and safety policies and to refresh their memories of previous, important training.

The UK government recommends risk assessments be reviewed annually, however, when it comes to specific accident reports, businesses may wish to increase the regularity of these check-ups to address the unique risks facing their workplace.