Certificate Iv in OHS – How to Investigate and Prevent Incidents


In the Certificate IV in OHS/WHS you will spend quite a large amount of time learning about incident investigation and prevention in the workplace.  This article reviews this process in detail.

Many incident* reports blame technical failure and/or human error. Such statements create a smoke screen, which obscures the complexity of incident causation and creates an impression that the cause of an incident and injury are beyond the scope of management control.

‘Technical failure’ sounds as if inanimate hardware can be blamed and ‘human error’ sounds as if an individual worker at the scene is to blame (Waring, 1996).

In order to investigate incidents competently, we need to understand how they typically occur. An incident usually results from the complex interaction of a number of causes. Identifying these causes requires consideration, not only of the obvious information gleaned from reports and witness statements, photographs and wreckage, but also the impact of aspects of the organisation of work, and human factors such as perception, motivation and behaviour.

So, while we may be investigating a ‘serious incident’ (which usually means serious injuries as the consequence*) we need to remember that a single set of causes can have a wide range of possible outcomes and consequences. The cause of someone’s near-miss* today may be someone else’s serious injury tomorrow.

There are three stages to OHS incident investigation:

1. Collect information to establish the facts.

2. Analyse the facts to establish root causes*.

3. Identify actions to prevent recurrence.

This competency element focuses on the first two stages as an introduction to identifying hazards.


The outcome of an investigation can only be as good as the quality of the facts established, which in turn depend on the quality of the data collected − which requires that appropriate techniques be used to collect the data.

In this section you will identify:

  • the sources of information and how best to obtain and record that information;
  • the need for corroboration of facts; and
  • the importance of the approach and behaviour of the investigator.

Standard techniques for collecting data include:

• personal observation, note taking and sketching;

• photography, audio taping and video taping;

• taking samples and physical evidence for laboratory examination, measurement of distances, sizes, temperatures and other parameters; and

• reviewing reports and personal interviews.

Ferry (Ferry, 1988) refers to the four ‘P’ witnesses:

• People whose information may aid the investigation, not necessarily eye-witnesses or participants. They include maintenance persons, supervisors, engineers, designers, technical advisors and doctors.

• Parts of machinery, communication systems, support equipment, fuels and lubricants, and debris at the site.

• Position of debris and items at the location, weather, operating conditions, lighting etc.

• Paper (including electronic) records, publications, directives, drawings and procedures.

‘Appropriate techniques’ also include the attitude and demeanour of the investigator when collecting the information.

At this level it is unlikely that you will be in charge of an investigation of a ‘serious’ incident, especially where outside agencies, such as the OHS regulator or the emergency services, are involved. So working as part of a team is an important skill.

If you are in charge, remember the safety of the people at the scene is the first priority. Then, when you approach the scene, take time to absorb both the overall picture and the details of the scene. People should know who is in charge, but you will need cooperation for the investigation to be successful. You are not a police person − you cannot demand cooperation!

certificate iv ohs training safety certificate iv in ohs - how to investigate and prevent incidentsPeople and interviews

Interviews should be conducted in private on a one-to-one basis. A cooperative atmosphere is vital, otherwise a witness may refuse information or tell you what they think you want to hear.

Strategies for creating a cooperative atmosphere include:

  • conducting the interview in a comfortable environment, including seating and introductory small talk;
  • making introductory comments that clarify the purpose of the interview and the use of the outcomes, and the confidentiality or otherwise of the information;
  • the investigator adopting the approach of seeking the ‘help’ of the witness;
  • encouraging the witness to tell what they have seen in their words without interruption; and
  • note-taking that is unobtrusive.

Avoid an adversarial approach. Interviews should not be interrogations, but rather should focus on ‘open questions’ that invite the person to tell their story rather than directing the answer.

NOT: ‘Safety training was pretty limited wasn’t it?’

BUT: ‘Tell me about the safety training’.

Where a number of people are interviewed, there should be an interview schedule to ensure that each person is asked the same questions in the same way. We know that the same set of circumstances may be viewed or reported differently by different people for various reasons.

These reasons may include:

• previous knowledge;

• objectivity; and

• a desire to avoid blame or protect others.

When obtaining information from people it is important to seek corroboration from a number of sources.

Photography and other visual records

Random picture taking is time consuming and may be misleading. Be systematic in the sequence and coverage of your photos. Allow for different conditions. A photograph taken during the morning will show a very different situation to one later in the day when the sun is in a different position, or if it is raining. Check the conditions at the time of the occurrence and attempt to match them as far as is practical.

Make a log of the circumstances of the photographs you take. The log should include:

• the time the picture was taken;

• who took it;

• conditions when it was taken (lighting, weather, etc);

• where it was taken from (a sketch map is useful); and

• what it shows.


Now that you know how to collect the information, it is important that you check the type of information to be collected.

This is where you will need your understanding of hazards as sources of potentially damaging energy and your understanding that the conditions that lead up to the loss of control usually occur over time. If you think you need a refresher on this, go to the online Readings and Resources and read the resource Hazard, Energy and Damage.

You also need some understanding of the elements that contribute to a systematic approach to managing OHS.

Such an approach includes the processes of:

• planning;

• allocating resources;

• communication and consultation;

• hazard management;

• record-keeping and reporting;

training and competency; and

• review and evaluation for ongoing improvement; all of which are combined in a methodical and ordered manner to minimise the risk of injury or ill-health in the workplace.

Factors that may have an impact on implementing a systematic approach to managing OHS may include:

• barriers to communication, such as language/literacy;

• workplace culture issues, such as management commitment, supervisors’ approach to compliance and general acceptance of the priority of safety;

• diversity of workers; and

• structural factors, such as multiple locations, shift work and supervisory arrangements.

The systematic approach to managing OHS is addressed in detail in competency unit BSBOHS401 Contribute to the implementation of a systematic approach to managing OHS.

Guidelines for collecting information in an investigation:

1. Start with the immediate facts of the occurrence including name, age, gender, time of day/week/shift, location and activity of all people present at the time.

2. Look beyond the immediate time frame of the occurrence to develop a time line that extends as far back as is considered relevant. This may include decisions regarding design or purchase of plant and equipment, maintenance history, and training.

3. Consider organisational and personnel factors such as management of change, communication processes, fatigue and task demands.

4. Seek corroboration of the ‘facts’.

5. Write a narrative of the occurrence (including the development of the pre-event conditions).

6. Do not accept ‘technical failure’ or ‘human error’ as causes.

7. Recognise your limitations and seek specialist advice when required.

Having collected the information you now need to analyse it to identify the hazard and determine cause.

LMIT delivers the Certificate IV in OHS and the Diploma in Occupational Health & Safety Completely Online.  The Advanced Diploma in OHS is also available via RPL only.

Published by: LMIT

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