The government has recently significantly improved the criteria for recognizing overwork as an industrial accident, including work hours and workload factors, in response to criticism that companies that force overwork or the government that overlooks it do not bear social responsibility, despite the fact that one worker dies from overwork on average per day in a long working environment. Previously, when a worker died due to overwork from duties and performance pressure, the burden of proof of overwork fell on the family members of the deceased. As a result, the proof of responsibility that was passed on to the family members or the victims of the accident has been criticized for only resulting in 20-30% approval of compensation for overwork-related deaths. Additionally, in response to criticism that the current standard for working hours is too long, a provision has been added that if the workweek exceeds 52 hours before the onset of illness, there is a strong correlation between work and illness. Furthermore, if work involves workload factors such as unpredictable work schedules, shift work, or insufficient holidays, even if the workweek is less than 52 hours, the relationship between work and illness is considered to increase.
Overwork death refers to an occupational disease directly related to long working hours. Although death from overwork is not a medical or legal term, it refers to cerebrovascular disease or heart disease (hereinafter referred to as 'cerebrovascular and cardiovascular disease') that leads to death due to blockage or bursting of cerebrovascular or cardiovascular vessels due to physical function deterioration caused by physical overwork and mental stress.
According to data from the Korea Workers' Compensation and Welfare Service in April 2018, the number of claims for work-related brain and cardiovascular diseases in 2017 was 1,809, of which 589 (32.6%) were approved as work-related illnesses, while the remaining 1,220 (67.4%) were denied. In general, while brain and cardiovascular diseases originate from an individual's health status, if there is significant evidence of a causal relationship between the disease and work-related factors leading to death, it may be recognized as a work-related illness.
According to the Supreme Court's ruling, even if there are underlying diseases such as hypertension and arteriosclerosis, brain and cardiovascular diseases may be recognized as work-related illnesses if there are work-related burden factors. According to the Korea Workers' Compensation and Welfare Service's guidelines, "when assessing work-related burdens, the timing of the incident close to the onset of the disease, work overload, cumulative fatigue over long periods of time, and work conditions should be considered. In particular, the working hours should be the main indicator, but all work-related situations, including work schedules, exposure to harmful work environments, physical intensity, and mental stress, should be evaluated concretely and objectively, and a comprehensive judgment should be made." In this article, we will examine relevant laws, guidelines, and precedents related to the proof of karoshi in detail.
■ Occupational Disease Reasons and Proof of Liability for Death from Overwork
In order for a worker to be recognized as having died from overwork, it must be proven that the death was due to a disease caused by work-related reasons. There are three types of proof of liability:
First, "situations where there has been a distinct physiological change due to sudden and unpredictable levels of tension, excitement, fear, surprise, etc. related to work and sudden changes in the work environment." This refers to cases where there has been a sudden and distinct aggravation of cerebrovascular or cardiovascular function due to a sudden and unpredictable event related to work that occurred within 24 hours prior to the onset of symptoms, along with a sudden change in work environment.
Second, "cases where short-term work-related burden has increased due to changes in the amount, time, intensity, responsibility, and work environment, causing physical and mental exhaustion that can clearly affect the normal function of cerebrovascular or cardiovascular systems prior to onset."
Third, "cases where chronic excessive work-related burden causes physical and mental stress that can clearly affect the normal function of cerebrovascular or cardiovascular systems due to changes in the amount, time, intensity, responsibility, and work environment." Even if a worker's work hours for the 12 weeks leading up to death from overwork did not exceed an average of 52 hours per week, if they performed work that falls under the "work burden aggravating factors," the possibility of approval for workers' compensation increases due to the increased relevance between work and illness.
The following are examples of work that falls under the "work burden aggravating factors": 1) work with unpredictable work schedules, 2) shift work, 3) work with insufficient holidays, 4) work exposed to hazardous work environments, 5) work with high physical intensity, 6) frequent foreign business trips with significant time differences, 7) work with high mental stress.
■ Guidelines for Work-related Diseases Related to Overwork Death
❍ Sudden Incidents and Rapid Changes in Work Environment
Sudden incidents and rapid changes in the work environment should cause a clear mental or physical burden that can significantly affect the normal function of the brain or cardiovascular system, such as tension, excitement, fear, shock, or a sudden physical burden. Therefore, the occurrence status of sudden incidents should be clear in terms of time and place, and there should be a correlation between such situations and the onset of symptoms. In other words, it should be a case where the sudden situation itself causes a physical or mental burden and symptoms appear within 24 hours after the occurrence of the sudden incident, and there should be a causal relationship between the event and the onset. Although most cases show an immediate onset pattern, there are cases where it takes time depending on the nature of the disease. Therefore, even if symptoms appear more than 24 hours after the occurrence of a sudden and unpredictable situation, if there is a recognized relationship between the event and the onset, work-relatedness can be recognized. Examples include direct involvement in a significant personnel accident related to work or witnessing such an accident, engaging in rescue activities or accident processing associated with the occurrence of an accident, causing physical or mental burden through excessive argument or assault with superiors, colleagues, or customers related to work, and performing work continuously for a long time without sleep.
❍ Short-term Work-related Burden
"Brain-vascular diseases" are likely to occur if the workload, work intensity, etc. increase rapidly within a short period (one week) before the onset. Therefore, this point should be considered when making a judgment.
Firstly, whether the workload or working hours have increased by more than 30% on average for one week during the 12 weeks (excluding the week before the onset) is evaluated as follows. ① Quantify the workload for the week before the onset and compare it with the average workload for the 2 to 12 weeks before the onset. ② If the average working hours for the 2 to 12 weeks before the onset are less than 40 hours, compare the change with 40 hours as a standard. ③ When performing night work, calculate working hours by adding 30% of working hours excluding rest time between 10 pm and 6 am.
Secondly, whether it falls under the category of "difficulty adapting to changes in work intensity, responsibility, and work environment" is evaluated by considering the following. ① Compare changes in responsibility according to work, increase in mental tension, changes and content of work environment, including the increase in working hours or workload of the employee within one week before the onset. ② Compare whether the changes in work burden of the employee were at a level that the employee could adapt to in comparison to the work or daily work for the previous 12 weeks (excluding the week before the onset).
Thirdly, the evaluation of short-term work-related burden is based on the evaluation of working hours, workload, work intensity, responsibility, rest time such as holidays or vacations, changes in work environment, and adaptation period. However, it should be comprehensively judged whether the possibility of onset is high, taking into account the age, gender, etc. of the employee in question.
❍ Chronic and Excessive Workload
"Work hours" refers to the time spent under the direction and supervision of the employer, including the preparation and organization time for work, and is a different concept from "working hours" stated in the employment contract. "Break time" refers to the time completely free from the employer's direction and supervision, and even if the guaranteed break time under the Labor Standards Act or the employment contract cannot be used for free rest or meals if the work is not stopped, it cannot be excluded from work hours. In assessing physical and mental burden factors, the work hours are first checked, and then other factors that increase work burden (shift work, holiday work, work environment, work intensity, time difference, mental tension, etc.) are considered.
The evaluation of work hours is calculated by adding up the hours worked each day for 12 weeks prior to the onset, confirming the average work hours for one week during the four weeks prior to the onset, and then evaluating the average work hours for one week during the 12 weeks prior to the onset in order. The daily work hours refer to the time from "the start of work to the end of work" minus "the time completely free from the employer's direction and supervision" in the employment contract. When working at night, the work hours are calculated by adding 30% to the hours worked between 10 p.m. and 6 a.m. after deducting break time. However, surveillance and inspection work or similar work does not apply to night work hours. Waiting time that occurs due to the nature of the work, such as surveillance or driving work, is included in work hours because the worker is under the direction and supervision of the employer for the purpose of the work.
■ Recognition of Overwork-related Death Requires Consideration of Reasonable Causal Relationship.
According to guidelines by the Korea Workers' Compensation and Welfare Service, the causal relationship between work and illness need not be proven solely by medical or scientific means. Instead, if a reasonable causal relationship is recognized from a legal and normative perspective, even in the absence of direct evidence regarding the cause of the illness, the health status of the employee at the time of employment, the cause of the disease, and other factors that may contribute to the onset of the illness can be considered based on experience and social norms.
According to court precedents, an "occupational accident" refers to a disease that arises from work performed by an employee, and thus there must be a reasonable causal relationship between work and illness. While the burden of proof falls on the party claiming a causal relationship between work and illness, if stress or overwork related to work significantly contributes to the onset or worsening of the illness, even if it is not the primary cause, a causal relationship between work and illness may be recognized. In this case, the causal relationship need not be clearly established by medical or scientific means, but should be considered based on relevant circumstances. This includes cases where a pre-existing condition that was previously manageable suddenly worsened due to excessive work demands.
In determining the causal relationship between work and illness, the health and physical condition of the employee in question, rather than that of an average person, should be taken into account.
In terms of the burden of proof for overwork-related deaths, courts have often recognized overwork and mental stress related to work as contributing factors to occupational disease. However, the Korea Workers' Compensation and Welfare Service's Disease Diagnosis Committee has not recognized insufficient work hours (less than 60 hours per week) as a cause of occupational disease due to overwork, based on its previous guidelines. Fortunately, the revised guidelines issued in 2018 supplement the previous guidelines for diagnosing occupational diseases due to overwork, by including mental stress or shift work, even if weekly working hours do not exceed 60 hours. It is hoped that this will increase the approval rate of overwork-related occupational diseases in the future.
