Investigating workplace accidents

By - , Build 150

There are standard practices to follow if an accident occurs on site. It’s important to know what these are and when WorkSafe NZ needs to be advised.

WHILE WE CAN DO our best to prevent them, accidents and near misses happen every day in New Zealand workplaces.

In the event of an accident

If an accident occurs on site, it is best practice to do an investigation and provide an analysis of what happened and why.

If a serious harm event occurs on your site, WorkSafe NZ must be notified as soon as possible (phone 0800 030 040). It is a legal requirement not to disturb an accident scene until clearance is authorised by a health and safety inspector.

In special circumstances, such as when there is a risk posed to people or property, you can access the site. This is covered under section 26 of the Health and Safety in Employment Act, but if you need access, check first with WorkSafe NZ.

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Investigate the immediate and root causes

When there is an accident, the investigation may reveal two types of causes:

● Immediate cause – the unsafe actions that led to the event.

● Root cause – the fundamental issue that caused the unsafe action.

An example helps to explain these. Dan is standing on the top rung of a three-step ladder installing electrical wiring. Dan loses his balance and falls.

The immediate cause is the risk of falling off the ladder by over-reaching.

The root cause may go back to the start of the day when Dan’s boss told the crew the job had to be completed today, no excuses. Even though step ladders were banned on site, the manager ignored this and turned a blind eye.

The root cause is that site management put safety to one side when there was a tight deadline.

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Finding the root cause

Identifying the root cause is the most important part for your report. There are several well worn steps to take when investigating the root cause.

Gather information

Start by taking notes and document physical evidence, witness statements and other information that might help piece together what happened.

It’s easy to forget the details in the days after the accident. Details such as where someone was standing and specific times of events when the incident occurred can be valuable later. Take lots of photos of the incident area for future reference, records and possible legal purposes.

Ask questions

The best way to get to the root cause of any accident is to keep asking ‘why?’ Good questions are:

● Why wasn’t this hazard identified, reported and corrected beforethe injury occurred?

● Why was a shortcut taken?

● Why was it not identified during inspections or toolbox talks orprestart meetings?

● If this was recorded as a near miss previously, why was it noteliminated, isolated or minimised?

Analyse information

Once you have collected all the information, pinpoint the immediate cause and the root cause of the accident.

Find a solution

Write down alternative solutions and ideas that will eliminate, isolate or minimise the root cause. Find solutions by asking those who work close to the hazards.

Implement the change into your health and safety systems, and record what you have done.

Follow up

Monitor your safety initiative and its effectiveness. Ask if you are seeing real change. For example, is the incident and accident register showing positive trends?

Give WorkSafe NZ written notice

You must provide WorkSafe NZ with written notice of the circumstances of the accident or serious harm within 7 days.

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Action helps eliminate future problems

Creating a safe worksite for employees, peers and yourself is an important part of a good workplace. Be aware of what you and the people around you are doing.

Completing the correct procedures after an accident occurs protects everyone involved and lessens the chance of the accident being repeated.

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For more

Site Safe offers a 2-day Supervisor Gold Card course that looks at how to run an investigation and how to identify and eliminate the risks associated with project hazards and unsafe behaviour. Visit

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