Safety Services


Investigate an Accident or Incident

It's important to investigate and record all accidents and incidents at UCL. This page provides guidance on how to investigate an incident.

On this page

Why investigate accidents and incidents? 

We must investigate all accidents and incidents so we can: 

  • Ensure action is taken to prevent a recurrence.
  • Meet statutory requirements*.
  • Help monitor and improve health and safety performance.
  • Provide information for responding to claims made against UCL.
  • Enable UCL to respond quickly and accurately to external enquiries.

*Under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR 2013) UCL has a statutory obligation to report certain types of incidents and accidents to the Health and Safety Executive (HSE). All reports to HSE are made by UCL Safety Services.

riskNET incident management

The results of the investigation must be recorded using the riskNET incident management tool. The tool has 3 distinct stages for incident management.

  1. The incident report – online report can be made by anybody, you do not need to be a member of UCL staff or a student.
  2. The Initial Assessment – all incidents must be reviewed.
  3. Further investigation – 2 types of investigation – Local investigation and Full investigation.

Each incident reported in riskNET is given a unique reference number that is used throughout each stage of the investigation. Incident reference numbers of related incidents should be referred to in the Initial Assessment. 

Who should investigate accidents and incidents?

Every department has an appointed Incident Co-ordinator. This is an administrative role that receives an email every time an incident is reported within their department. The Incident Co-ordinator will assign the incident to the person who will review the incident based on the following criteria.

  • For incidents that cause, or have the potential to cause, injury or ill-health to an individual, the manager of the involved/injured person (IP) must be involved in the investigation.
  • For all incidents including those where there no injury or ill-health is suffered and no particular individuals are involved, the manager or responsible person in charge of ensuring the activity is carried out safely should lead the Initial Assessment and be involved in any further investigation. This could be the PI or the person responsible for the area such as the lab or studio manager.
  • All investigations should be carried out by competent investigators who have completed the Incident Investigation course.
  • All CL3 and LGMO (living genetically modified organisms i.e. at UCL this would be genetically modified animals in a BSU) lab managers must be competent investigators in addition to other requirements for their role.

Departmental Safety Officers (DSO) may assist with the investigation but should not be assigned an Initial Assessment unless they fit the requirements through their other roles. 

The Head of the Department and the departmental Safety Committee should ensure that incidents are investigated and the results are recorded on riskNET.

Initial assessment

Once an incident has been assigned for investigation, the investigator has 5 working days to complete the Initial Assessment. They must answer the following questions.

  • What happened – completing all parts of the incident report with full details of any injury or damage.
  • How did it happen – accidents and incidents have many causes. What may appear to be bad luck (being in the wrong place at the wrong time) can, on analysis, be seen as a chain of failures and errors that lead almost inevitably to an adverse event. These causes can be classed as:
    • Immediate – the agent of injury or ill health (the blade, the substance, the dust etc).
    • Underlying – unsafe acts and unsafe conditions (the guard was removed, the ventilation was switched off etc).
    • Root – the failure from which all other failings grow, often remote in time and space from the adverse event (e.g. failure to identify training needs and assess competence, low priority given to risk assessment etc).
  • What can be done to stop it or similar incidents from happening again – the investigator needs to identify suitable measures to resolve the flaws that were identified and implement these measures to prevent a recurrence. This may include:
    • Reviewing risk assessments and safe systems of work.
    • Adjusting the work layout or environment.
    • Providing training and/or supervision.
    • Repairing, maintaining or replacing tools and equipment.
    • Providing Personal Protective Equipment (PPE).

Should the investigator find that although they can identify immediate causes and control measures, further investigation is necessary, riskNET will assist by leading the investigator through an assessment of the potential risk.

Potential risk

Potential risk is when an investigator compares what actually happened to what could have happened. For example, if someone trips down the stairs, there are three possible levels to the consequence.

  1. With good luck – the person gets a bruise and may feel scared but can go on with their day often forgetting to report the incident.
  2. On average – the person sprains their ankle or other joint or may end up with a broken bone. This will get reported.
  3. With bad luck – the person receives a head injury or injury to their back and neck with the worst-case scenario leading to death.

When the investigator carries out the Initial Assessment and assigns the potential consequences, they are assigning what the average consequence would be and should ensure that the investigation level is comparable with that potential consequence.

It is important to remember that not every incident needs to be investigated as if it could result in death, but in some cases investigating incidents that have minimum consequences due to luck may result in preventing more serious consequences in the future.

riskNET will prompt the investigator to open a further investigation should an incident be rated as a high potential risk by the factors entered into riskNET, but this does not happen automatically and it is the responsibility of the investigator to make the final decision as to whether further investigation is needed.

Location is a factor that is not taken into account by riskNET and the investigator should always consider if the location of an incident affects the risk potential. For certain locations, UCL has stated that it does and when an incident is either within these locations or affects these locations a local investigation must be opened.

The current list of incidents with known high potential risk are:

  • Incidents that occur during research work in CL3 laboratories – UCL policy is that for any incident that affects, or could potentially affect, the safe running of a CL3 lab, a local investigation must be opened and the BioChem team informed.
  • Incidents that occur during research work in LGMO laboratories.
  • Incidents that involve the failure of engineering control measures related to CL2, CL3 and LGMO work.
  • Incidents that involve the loss of contaminate for CL3 or BSU laboratories.

For all other activities, if the riskNET prompt to open a further investigation is not followed, the investigator must add a comment to the record on why a further investigation was not needed when they complete the Initial Assessment. 

If the investigator believes that further investigation is required and riskNET not does provide the prompt, the investigator can open a local investigation. Best practice would be to include a comment about why a further investigation is needed.

Local and full investigations

There are 2 types of further investigation that a department may open. riskNET provides a framework for the investigator to ensure that all aspects of the investigation are covered and recorded.

Once an investigator has chosen to open an investigation they can assign additional people to help with the investigation. These could be the Departmental Safety Officer, the line manager of people involved or the supervisor of the areas where the incident took place. It may also involve people from other departments.

For incidents with known high potential risk, the specialist from Safety Services should be part of the team. For example, for incidents that require further investigation, the Biological Safety Officer (BSO) should be added to the team.

Local investigation

This is the most common form used by UCL and this can be opened by any investigator.

Full investigation

This requires agreement with the Head of Department and Safety Services to open. It may be required in the cases where a RIDDOR report has been made or where the incident and therefore the investigation may have consequences across UCL. If riskNET prompts or the investigator believes a full investigation is necessary, you should contact the lead advisor for the department as soon as possible.

riskNET incident management workflow

  1. Incident report made.
  2. System-generated email issued to the Incident Co-ordinator.
  3. Incident Co-ordinator allocates the incident to a competent investigator.
  4. System-generated email issued to the investigator.
  5. Investigator completes the Initial Assessment.
  6. Investigator opens Local or Full investigation if necessary.
  7. Investigator reports to the departmental Safety Committee.

Carrying out an investigation

An investigation will involve an analysis of all the information available to identify what went wrong and determine what steps must be taken to prevent the adverse event from happening again. 

  • Physical – the scene of the incident.
  • Verbal – the accounts of witnesses.
  • Written – risk assessments, procedures, instructions etc.

Remember it is not about blaming anyone. The investigator is gathering information and looking at the causes of the incident so we can try and stop it from happening again.

Gathering information

To begin an investigation, the first step is to gather all the relevant information. It is important to capture information as soon as possible, this stops it from being corrupted (e.g. items moved etc). If necessary, work must stop and unauthorised access should be prevented.


The scene of the incident should be made safe and preserved. First Aiders (or the Emergency Services) should be allowed to treat any injuries but no other changes should be made to the scene until physical information has been gathered.

Examples of physical information to gather:

  • Exact location.
  • Weather conditions (if applicable).
  • Lighting and temperature.
  • Condition of flooring or work surfaces.
  • Condition of any equipment or tools involved.
  • Any chemicals, substances or other materials involved.
  • Condition of any Personal Protective Equipment (PPE) and if it was worn.

An image of the scene can be extremely beneficial in an investigation and capture a lot of physical information.  


Speak to those involved to gather information to fill any gaps and find out more. These could be informal interviews at the scene. You should note the names of those involved including any witnesses before they leave the area as you may not be able to interview them at the scene or may require a more detailed interview later on.

When you conduct an interview make it clear what is happening and the purpose of the investigation. Tell them who you are and which incident you are investigating and why.

  • Remind them of the details of the incident and why you need to speak to them (e.g. as a witness or the supervisor of someone who was injured).
  • Give an indication of how long the interview might take, and offer to revisit/come back another time if needed.
  • Make it clear that this is not about establishing blame but that you are looking at the causes of the incident to find out what could be done to stop it from happening again 
  • Indicate what will happen with your findings (e.g. you will be reporting back to the Head of Department).

If you are not comfortable interviewing close colleagues or senior managers, you may want to ask a colleague to help or contact Safety Services for their assistance.

Interview Techniques

There are lots of different ways of asking questions when carrying out an investigation.

1. Open questions

This prompts the person you are interviewing to give you a longer/more detailed response:

  • Tell me what happened?
  • When did that happen?
  • Where did that happen?
  • How did that happen?
  • Who was there?

2. Closed questions

You can use closed questioning along with open questions to clarify or probe for further details. For example, use closed questions that prompt an either/or type response (e.g. yes/no, black/white) to confirm or clarify a fact.

3. Funneling questions

Funneling questions will help you find out more detail by asking a series of questions around a particular theme, building on the information given in the responses given (e.g. to find out more about the equipment that was involved in the incident).


  • Leading questions – these subtly prompt the responder to answer in a particular way.
  • Assumptions – you may be familiar with the work and the people involved but don't assume they followed the standard procedures or carried out the task as you would have expected.

Examples of written information:

  • Date and time.
  • Risk assessments.
  • Safe systems of work/procedures/method statements.
  • Safety data sheets.
  • Manufacturer instructions for equipment and tools.
  • Maintenance records for equipment and tools.
  • Local inspection records (e.g. equipment pre-use checks, workplace inspections).
  • Training and induction records.
  • Shift times/rotas.
  • PPE log.

Analysing the causes of incidents

Accidents and incidents have many causes. What may appear to be bad luck (being in the wrong place at the wrong time) can, on analysis, be seen as a chain of failures and errors that lead almost inevitably to an adverse event.

These causes can be classed as:

  • Immediate  the agent of injury or ill health (the blade, the substance, the dust etc).
  • Underlying  unsafe acts and unsafe conditions (the guard removed, the ventilation switched off etc).
  • Root  the failure from which all other failings grow, often remote in time and space from the adverse event (e.g. failure to identify training needs and assess competence, low priority given to risk assessment etc).

To identify the underlying and root causes, take the immediate cause of the incident and ask the question 'why?' five times. The answer to the why will come from the information gathered as part of the investigation. For example: 

Why did the worker injure himself?Because he fell from a ladder.Immediate
Why did he fall from a ladder?Because he was not holding onto the ladder and overbalanced backward.Underlying
Why was he not holding onto the ladder?Because he was using both hands to remove a large section of guttering.Underlying
Why was he using both hands to remove guttering?Because the system of work for gutter replacement was flawed so it was not possible for the worker to maintain three points of contact with the ladder.Underlying
Why was there a flawed system of work in place?Because the job had not been properly planned in advance.Root

Identifying and implementing suitable risk control measures

Like the types of cause, control measures come in 3 types:

  1. Immediate – actions that were taken at the time of the incident or within the 5 working days before the Initial Assessment is completed. These usually involve making the site, equipment and people safe, through quarantining the access, providing first aid, cleaning up etc.
  2. Short term – actions that can be arranged quickly such as refresher training, reviewing and updating the risk assessment or actions that only provide short term safety such as temporary support for unsafe walls or floors, altering walkways to avoid the danger etc. Short term actions should be replaced with long term control measures within 12 weeks. If the long term control measures take longer to implement a review should be in place at least every 12 weeks.
  3. Long term/permanent – actions that will lower the risk of the hazard either by providing ongoing control measures such as implementing a new training and supervision scheme or eliminating or substituting the risk such as a change in policy or procedure.

The root cause of the incident will indicate which control measures would be most effective. The Investigation can be closed once the control measures have been accepted and an action plan put in place. The action plan will then be used to ensure the completion of all actions for the immediate, short and long term control measures.


For those who are responsible for, or assist with, carrying out an accident or incident investigation, an eLearning module entitled 'Incident Investigation' is available.

This course will provide you with a systematic approach to understanding why an accident or incident happened and the steps to take to ensure that it will not happen again.

Incident Investigation Training

Last updated: Wednesday, May 25, 2022