Ep 4: The links between fatal and non-fatal accidents based on >23k incidents

Is there a connection between fatal and non-fatal accidents, or is it a fallacy to focus on the minor potential events with the hope of managing the major events?

Today's study explores these relationships based on 23k reported serious accidents in the Netherlands.

Ref: Bellamy, L. J. (2015). Exploring the relationship between major hazard, fatal and non-fatal accidents through outcomes and causes. Safety Science, 71, 93-103.

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Intro/Output "Dark Synth Wave" by ElephantGreen(PixaBay.com)

Episode Transcript

(00:07):
Think about the routine incidents in any high risk
environment. A tiny gas leak, a minor
equipment malfunction, A brief loss of control.
We often treat these as isolatedevents, easily managed.
But what if there's an unseen but rather simple thread
connecting those minor occurrences directly to the
devastating catastrophes? A connection we've simply failed

(00:27):
to grasp. Good day everyone.
I'm Ben Hutchinson. This is Safe Haz, a podcast
dedicated to the thrifty analysis of safety, risk and
performance research. Visit safetyinsights.org for
more research. Today's study is by Linda
Bellamy titled Exploring the Relationship between Major Fatal
and non Fatal accidents through Outcomes and Causes, published

(00:50):
2015 in Safety Science explored the critical link between major
hazards in both fatal and non fatal accidents.
To do this, the research analysed over 23,000 serious
occupational accidents from the Netherlands between 1998 and
2009. This extensive data was analysed
using a specialised tool called Storybuilder which use hazard

(01:12):
specific bow tie diagrams to mapout accident causes and effects.
The study score goal was to directly investigate any
connections between minor and major accident scenarios.
So with a bit of background, major action investigations
often reveal that organisations have types of blind spots and
overlook in hindsight, warning signs leading to accidents

(01:35):
incubating in the background, and complex systems have been
argued to have a type of inherent potential danger.
However, unlike those massive high profile events that make
national news, everyday occupational accidents, even
those with multiple fatalities, rarely get the same public
attention. The academic discussion on

(01:55):
accent relationships has also been quite divided.
Earlier research suggested that smaller accidents are symptoms
and bigger problems, implying that fixing small ones may help
to avoid some of the larger ones.
Conversely, more recent views, especially after major
industrial disasters like the Texas City refinery explosion,
argue that occupational injury stats are not reliable

(02:18):
indicators for process age performance, suggesting a
complete disconnect. Andrew Hale in 2002 even stated
that assuming preventing minor accidents automatically prevents
major ones is based on careless and unsupported reasoning.
Balamy's study directly tackles these differing viewpoints head
on. So what did they find?

(02:39):
Well, the analysis of those 23,000 serious dust accidents
revealed A crucial insight. Smaller, more frequent accidents
can provide valuable informationabout the causes of bigger,
rarer catastrophic accidents, but only if you're looking
within the same hazard category.So 36 hazard categories were
explored in this research included a range of things but

(03:02):
hazard categories like explosions, falling objects,
electrical contact, and more. This finding directly
contradicts the idea that personal and process safety are
totally unrelated. Instead, Bellamy's research
concludes that there is a link between occupational and process
safety and between fatal and nonfatal occupational accidents and

(03:23):
that link is the hazard. Here's my other key results.
So a commonality in causal or contributing factors across the
900 plus fatal accidents in thissample there was no barrier
failure caused unique to fatal accidents that hadn't also
occurred in non fatal accidents.This strongly suggests that less
serious accidents of the same hazard type can indicate

(03:45):
potential for more serious events.
Lethality inverse frequency. The study used accident ratio
hills, which will make more sense if you actually read the
paper, and this shows how hazards differ in their outcome
severity. Interestingly, the most lethal
hazards like drowning are not necessarily the biggest killers
overall. For instance, falls from height

(04:06):
or contact with falling objects cause far more serious and fatal
accidents overall, even if otherhazards might be statistically
more lethal per incident. Correlation with hazard types.
Well, overall general lethality didn't correlate with the accent
numbers. A significant positive
correlation was found between non fatal and fatal victims
within the same specific hazard types.

(04:28):
This is largely due to the common element of exposure to
the hazard on barrier failures. Fatal and non fatal accidents
often share the same underlying barrier failures, but these
failures don't always occur in the same proportions for
different severity outcomes. Importantly, there is no one
fatal barrier failure cause which has not also occurred in

(04:50):
the non fatal accidents. This suggests a role in breaking
down incidents at a barrier level.
So what can we make of these findings?
Because the underlying contributing and causal factors
and barrier failures for same hazard accidents can be similar,
investigating minor frequent incidents for their high
severity potential and fixing those specific safety barrier

(05:11):
problems could help prevent bigger, more severe incidents of
the same time. It's not enough just to look at
the frequency hazards and their barriers need independent deeper
scrutiny. Also they provide examples of
accidents and the types of barrier failures. 1 is the
American trial scaffold collapsed in 2003.

(05:32):
Now very quickly this multi fatality accidents underlying
tributing or underlying causal factors like deficient design
and anchoring were also found inthe less severe non fatal
scaffold accidents in the database.
This case study and others illustrate that the causal and
attributing factors of major incidents are often mirrored in
seemingly minor ones when the hazard type is the same.

(05:54):
When I think about this, I thinkthere's a clear finding that
there can be a connection between fatal and non fatal and
that connection is the hazard itself.
Of course, other work and more recent work like that from to
Hello L and team provides nuancearound the magnitude of energy
and more, suggesting there mightbe some differences.
But Simply put, focusing on the hazard scenarios should be one

(06:16):
key focus. A slip hazard may not be seen as
fatal, but if it's at height in that scenario, then becomes
fatal. So what were some limitations?
It's vital to remember that thisstudy, like any study based on
accident data, has limitations. The information comes from, in
an instance, hindsight investigations, which are always

(06:37):
subject to investigative biases and philtres.
For example, regulators often focus only on the most severe or
legal breaches. Also, and this one I think is
really prevalent, is that what'slisted as a causal factor
depends on the investigator and their own mental models and the
accident models that they use, and then your reporting
taxonomies that they follow and a whole range of other pressures

(07:00):
and influences. Again, what you look for is what
you find. That's it on Save As.
I'm Ben Huntington and I hope you found this useful.