3 key reasons to investigate incidents involving hazardous chemicals

Apr 1, 2019 Posted by Walter Ingles

Incidents involving hazardous chemicals happen every day at workplaces across Australia. A cylinder of flammable gas gets dropped, a worker spills acid over their apron and boots, a forklift impacts a safety cabinet: even when no-one is injured and there aren’t any notification requirements, the incident may be worth investigating. This blog looks at the three primary reasons why your workplace should be reviewing and investigating any workplace injuries, incidents, or near-misses that involve hazardous chemicals.

REMEMBER: Hazardous chemicals create complex workplace hazards. A near-miss or close call could be an indicator that a chemical hazard exists and has never been properly identified or controlled.

1. Prevent the incident from escalating into something more serious

A lab worker spills acid onto their pants while conducting an experiment. They bypass the safety shower and change their clothes in the staff toilets. They suffer minor burns to their hands while removing their pants.

The chief purpose of any incident investigation is to establish the root cause and prevent the incident from ever happening again. In the case of near-misses, your investigations will be focused on preventing the incident from escalating into something more serious. In the example above, you would begin your investigation looking into why the acid was spilled.

To get to the reason, many investigations use an interrogative technique called ‘The 5 Whys’. This technique acknowledges that incidents rarely have a single cause and enables a line of continued questioning until you get to the heart of the matter. Using the earlier workplace example you might determine the worker was in a hurry because they had fallen behind their work schedule and left the lid off the chemical container. Let’s take a look at ‘The 5 Whys’ in this generic example below:

Using ‘The 5 Whys’

Question Why Reason

Why did acid spill onto your pants?

1st why

The chemicals fell off the workbench and the splashed onto the pants when the container hit the floor.

Why did the acid fall off the workbench?

2nd why

Slipped on water and collided with the bench causing the container to fall to the ground.

Why was the container of acid able to spill liquid when it fell?

3rd why

The lid wasn’t on the container.

Why wasn’t the lid on the container?

4th why

Had to go to the toilet and didn’t put the lid while using the restrooms.

Why didn’t you put the lid back on?

5th why

Had fallen behind work schedule and in a hurry to get the procedure finished. Didn’t think it was important.


Most hazardous chemicals have strict handling and storage requirements and many require the consistent use of PPE. Investigating a HAZCHEM incident using a series of strategic ‘whys’ often uncovers a regular practice of workers not following safety procedures or using their PPE incorrectly.  Workers are often embarrassed when they’ve done something wrong and it can take a long line of questioning to finally uncover the root of the problem.

TIP: Use the ‘5 Whys’ to open up new lines of questioning. From the example above you might also question why there was water on the floor, why the safety shower was by-passed and why the worker was behind schedule.

 2. Uncover chemical hazards and system failures

A worker was transferring sodium hydroxide from a bulk tank into subsidiary vessels. The worker was burned on the foot when chemicals leaked from a broken PVC elbow.

Effective incident investigations go beyond a broken PVC elbow and look for the system failures that allowed the worker to be exposed to leaking chemicals. In this circumstance it could be a combination of factors including:

  • Material failure. The PVC elbow was not suited to the size of the tank and the nature of the chemicals. It was never likely to last beyond a few months.

  • Personnel failure. The PVC elbow had been struck with a forklift but never reported by the driver.

  • Task failure. There were no programmed inspections or safety audits in place.

  • Environment failure. The lighting was dim and the worker didn’t notice the leaking PVC elbow.

  • Management failure. Workers had never been trained to inspect and check the integrity of the tank before transferring chemicals.

TIP: Effective incident investigations use causation models like the Management Oversight and Risk Tree (MORT) which group key causes into five distinct areas (material, personnel, task, environment, management.)

3. Expose compliance issues

A worker slips and falls on a wet floor. Corrosive cleaning chemicals soak into their clothes and they suffer chemical burns to their legs and back. The highly concentrated corrosive cleaner was being used to remove stains from the floor. The chemical container was unlabelled and the workers didn’t fully understand the hazards of the chemicals.

Incident investigations can also expose issues of non-compliance. When you first introduce a chemical to the workplace, you issue PPE and train your workers. But over time new workers are hired, people become complacent, and new challenges arise. In the example above, a group of workers had accidentally used a concentrated mix of a highly corrosive cleaning chemical to remove stains from the floor.

Sometimes it takes an incident investigation to realise that chemicals are being incorrectly labeled and (in this case) grabbed in error. Closer examination may uncover a whole series of compliance issues in your chemical stores: cleaning chemicals in unlabelled portable containers, containers put away without securing the lids, mixed classes of hazardous chemicals in the same safety cabinet.

Next steps

HAZCHEM incident investigations are an important tool for preventing injuries and dangerous incidents involving hazardous chemicals. For more information about how to conduct an effective investigation please download our free eBook Key Steps in a HAZCHEM Incident Investigation. It’s the next step in chemical safety and compliance.

Key Steps in a HAZCHEM Incident Investigation


Walter Ingles

Walter Ingles Compliance Specialist

Walter is STOREMASTA’s Dangerous Goods Storage Specialist. He helps organisations reduce risk and improve efficiencies in the storage and management of dangerous goods and hazardous chemicals.

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