Accidents and incidents

Introduction

Ensuring safety at work essentially means preventing accidents at work. An accident at work can be defined in different ways depending on the context in which it is used. Often also the word incident is used, sometimes as a broader term encompassing ‘an accident' as a specific type of incident, but sometimes the words accidents and incidents refer to two different types of events.

Prevention of accidents at work focuses on the causes of accidents. Accident causation models provide a theoretical basis for explaining how accidents at work occur. Statistical data provide information on causes and circumstances of accidents at work.

Definitions of accidents and incidents

Numerous definitions exist of accidents and incidents at work. The nature of the definitions often depends on the context and the purpose such as accident prevention, workers' compensation and statistics.

The definition of an accident at work in the context of accident prevention

In the context of accident prevention, the phenomenon of accidents and incidents is often viewed in light of accident investigation and analysis. The main purpose is to gain insight in the (underlying) causes in order to prevent accidents in the future and to improve the safety of the workers. Definitions of accidents and incidents reflect this purpose and refer in one way or another to how accidents occur.

The definition of an accident provided by Heinrich in the 1930s is often cited. Heinrich defines an accident as an unplanned and uncontrolled event in which the action or reaction of an object, substance, person or radiation results in personal injury or the probability thereof. Variations on this definition can be found throughout the safety literature. Bird and Germain for instance define an accident as an unintended or unplanned happening that may or may not result in property damage, personal injury, work process stoppage or interference, or any combination of these conditions under such circumstances that personal injury might have resulted^[1].

In more recent literature, it is often argued that the notions "unplanned", "uncontrolled" are misleading. This might give the idea that the event is related to fate or chance. It can't be controlled. However, when the causes are determined, it is usually found that many events were predictable and could have been prevented if the right actions were taken. This implies that the event is not one of fate or chance.

Most contemporary definitions don't include the notion "unplanned" and/or speak in more general terms of "incident" instead of accident. The ISO 45001 standard focuses on the definition of an incident^[2]. An incident is referred to as an occurrence arising out of or in the course of work that could or does result in injury and ill health. An accident is regarded as a particular type of incident in which an injury or ill health actually occurs. A near-miss is an incident where no injury or ill health occurs. Therefore, an incident can be either an accident or a near-miss.

Although the term incident is regarded more and more as a broad term encompassing all events causing injury or material damages and also near-miss events, this is not always the case. Incident is often also referred to, as an event that has the potential to cause harm, but didn't. Incident is then regarded as a synonym for a near-miss event^[3]. These differences in terminology and definitions have to be taken into account when browsing through safety literature or when looking into accident investigation techniques.

The definition of an accident at work in the context of Workers' Compensation Systems

In the context of Workers' Compensation Systems accidents at work are regarded from the perspective of compensating the victim. Usually the term occupational accident is used and the definition contains the elements that allow determining whether or not the victim of an injury at work can claim compensation from the Workers' Compensation Systems.

The standard definition of occupational accident contains the following elements^[4]:

1. fortuitous, sudden, or unexpected external event;
2. during working hours/on the way to and back from the workplace;
3. arising out of work performed in the course and the scope of employment;
4. bodily harm;
5. causal link between the event and the harm.

The fact that occupational accidents are fortuitous, sudden, unexpected external events allows making a distinction between accidents and diseases. Diseases are usually caused by a process extended over a longer period of time and not by a sudden event. Although this distinction seems straightforward it is not always the case. For instance, back problems can be the result from continuous exposure or be linked to a sudden event.

Occupational accidents occur during working hours and/or on the way to and from the workplace. In a broad sense occupational accidents also include commuting accidents. However, some Workers' Compensation Systems exclude this type of accidents.

The definition of an occupational accident also includes the fact that the accident has to arise out of work performed in the course and the scope of employment. This criterion often leads to discussions about accidents during activities in the workplace where the link with the scope of employment is somewhat questionable e.g. during excursions, doing private work or business at the workplace, etc. The criterion injury usually comprises not only bodily harm, but also mental health problems caused by an accident.

Finally, the concept of an occupational accident is based on the fact that there has to be a causal link between the event and the injury. Only direct consequences of the occupational accident can be compensated. Thus, when a pre-existing disease is aggravated or accelerated by an accident, compensation is payable only for what is reasonably attributable to the accident^[4].

The definition of an accident in the context of statistical data

Although statistical data on accidents at work are often based on data provided by Workers' Compensation Systems, the definition should be considered from a different angle. It is not a question of determining whether or not the victim should be compensated, but whether or not the event should be registered as an accident at work for statistical purposes (trends, comparisons, etc.). The definition used in the European Union is developed by Eurostat in the framework of ESAW, European Statistics on Accidents at Work^[5] and included in annex IV of Regulation 1338/2008/EC^[6]. This Regulation states that Member States are obliged to supply statistics to Eurostat on accidents at work.

An accident at work is defined as a discrete occurrence in the course of work which leads to physical or mental harm^[5]. This includes cases of acute poisoning and wilful acts of other persons, as well as accidents occurring during work but off the company’s premises, even those caused by third parties. It excludes deliberate self-inflicted injuries, accidents on the way to and from work (commuting accidents), accidents having only a medical origin and occupational diseases.

The phrase in the course of work means whilst engaged in an occupational activity or during the time spent at work. This includes cases of road traffic accidents in the course of work.

A fatal accident is defined in ESAW as an accident leading to the death of a victim within one year of the accident. A commuting accident is defined as an accident that occurs during the normal journey between the home, the place of work and the usual place where meals are taken. Only accidents at work with an absence of more than three calendar days are included in the ESAW data. This means that an accident at work is included in the ESAW database if the person is unfit for work for more than three days, excluding the day of the accident. Consequently, ‘more than three calendar days’ means ‘at least four calendar days’. Only full calendar days (not only working days) of absence from work have to be considered^[5].

Causes of accidents at work: accident models

Prevention of accidents at work focuses on the causes of accidents: what are the causes lying underneath the event of an accident (or incident). Insight in the causes is essential to prevent future (similar) accidents. Therefore, revealing all the causes leading up to an event of an accident is the basis of investigation and analysis. Accident causation models provide a theoretical basis for explaining how accidents at work occur.

A well-known accident causation model is certainly the domino theory of Heinrich. Heinrich captured the accident sequence in five factors portrayed as domino blocks^[7]. It is a linear accident sequence of preceding factors leading up to the accident and resulting in an injury. The removal of a domino block – preventive action – results in the fact that the accident will not happen. The domino theory has been updated since by several authors and still forms the basis of many accident investigation techniques. These models are referred to as sequential accident models.

Other models have been developed since, for instance the Swiss cheese model of James Reason^[8]. The Swiss cheese model shows several layers or barriers between management decision-making and accidents and incidents. Each of the barriers has holes and accidents or incidents occur when the holes in these layers align. Reason makes a distinction between active and latent failures. Latent failures find their origin in fallible decisions by high-level decision makers (and designers). Active failures are a mere symptom of latent failures.

The accident causation models based on the domino model or the Swiss cheese model are described as sequential models depicting a linear cause-effect relation between consecutive events leading up to an accident. Over the recent decades systemic models have been developed. These models are based on the principle that the interrelations among the causes of the accident are non-linear and include multiple feedback loops. The systemic models investigate the causes of accidents mainly by considering the interactions among the principal system components (social, technical, human, organisational and managerial). The most used systemic accident analysis methods are Accident Model and Processes (STAMP), Functional Resonance Accident Model (FRAM), and AcciMap ^[9][10][11].

Statistical data on accidents at work

Data on accidents at work are available through national reporting systems (e.g. accident insurers) or through surveys. The European Labour Force Survey (EU-LFS) ad hoc module 2007, 2013 and 2020 provides data on self-reported occupational accidents in the year preceding the survey, irrespective of whether these accidents resulted in absence from work. ESAW, the European Statistics on Accidents at Work, is based on reporting systems from the Member States and includes data on accidents at work with more than three days of absence from work (non-fatal accidents) and fatal accidents. The ESAW data and the results from the EU-LFS are available in data tables in the data browser from Eurostat https://ec.europa.eu/eurostat/databrowser/explore/all/all_themes?lang=en. The overview below is based on these data tables.  

How many accidents at work occur?

In 2019, there were 3.1 million non-fatal accidents that resulted in at least four calendar days of absence from work and 3 408 fatal accidents in the EU^[12]. The overall trend shows that accidents at work are decreasing, not only in absolute numbers but also the incidence rate (table 1). The incidence rate expresses the number of accidents in relation to the number of persons employed (100 000). The decreasing trend of accidents can be linked to changes in the world of work with an employment shift from traditionally high-risk sectors such as agriculture or mining to more service-oriented sectors.

Table 1 – Non-fatal and fatal accidents at work – 2010 – 2019 (ESAW)

Source: table compiled based on data from the Eurostat database – Non-fatal Accidents at work by NACE Rev. 2 activity (HSW_N2_01) & Fatal Accidents at work by NACE Rev. 2 activity (HSW_N2_02)^[13]

Who are the victims?

Men are more often victim of an accident at work than women. The LFS data from 2020 show that on average 2.8% of the male employed persons reported having a work accident during the last year compared to 1.8% of the female employed persons. Young, male workers are most at risk (figure 1).

Sectors and activities

The sectors with the most non-fatal accidents (in numbers) are manufacturing (18.7% of the EU total in 2019), wholesale and retail trade (12.3%), construction (11.8%), and human health and social work activities (11.0%).

Between 2010 and 2019, the number of non-fatal accidents decreased in each of the five high-risk sectors (figure 2). The largest decrease in non-fatal accidents in the EU was recorded in manufacturing (152 000 less non-fatal accidents) and construction (-104 000), with smaller decreases in agriculture, forestry and fishing (-19 000) and transport and storage (-10 000).^[15]

What are the causes?

The ESAW methodology describes the accident cause as the last event differing from the norm that resulted in an accident. In 2019, the most common causes of non-fatal accidents at work in the EU included losing control of machines, tools or transport and handling equipment (21.5 %), body movement under or with physical stress (19.6 %), and slipping, stumbling or falling (18.6 %). Losing control of machines, tools or transport and handling equipment (27.0 %) was also the most frequent cause of fatal accidents at work, followed by Slipping, stumbling or falling (15.3 %) and Breakage, bursting or collapse of material agents (11.3 %).  More detailed data by cause and sector show the correlation between activities and causes. For instance, in the Transportation and storage sector Losing control of machines, tools or transport and handling equipment account for almost 1 out of 2 fatal accidents. In the Construction sector Slipping, stumbling and falling is the most common cause of fatal accidents (figure 3).

What are the consequences?

The most obvious consequence of accidents is the fact that they result in absence from work. Data show that almost 50% of accidents at work result in less than 14 days absence from work.

The most common types of injury that result from accidents are Dislocations, sprains and strains and Wounds and superficial injuries followed by Concussions and Bone fractures (figure 4). All other types of injuries account for 10% of all accidents at work.    

Table 2 – Accidents at work by days lost – 2019 (ESAW)

Source: table compiled based on data from the Eurostat database - Accidents at work by days lost and NACE Rev. 2 activity (hsw_n2_04)^[17]