I. Death from Overwork and related Verifications

A. Introduction

An occupational fatality directly related to long working hours is death from overwork. Although it is not a medical or legal term, “death from overwork” is used to describe a fatality from cerebral vessel disease or a heart attack (hereinafter referred to as "cerebral vessel or heart disease") caused by physical exhaustion and mental stress. Lee, Heeja,「Death from Overwork and Occupational Compensation」, Joongang Economy, 2014, p. 162.
According to data from the Employee Welfare Corporation released on April 11, 2018, 1,809 applications were filed for cerebral vessel or heart disease to be determined as death from an occupational illness in 2017, with 589 (32.6%) of these applications approved and 1,220 (67.4%) rejected. In general, cerebral vessel or heart disease is attributed to an individual's personal health, but can be recognized as a work-related fatality if there is a significant causal relationship, in the fatality, between the condition and the work. Lim, Jongryul, 「Labor Law」, 14th Ed., Parkyoungsa, 2016, p. 482.

According to judicial rulings, cerebral vessel disease can be recognized as an occupational illness if there are some affecting factors related to work performance that cause the disease, even if there already existed some common conditions such as hypertension or hardening of the arteries. The Employee Welfare Corporation Guidelines regulate that judging whether there is a "burden on the work" should consider workload at the time of the incident, accumulation of fatigue over a long period of time and working conditions. They define work hours as a key component, and comprehensively examine all situations related to work such as schedule, exposure to a harmful working environment, physical strength, and mental stress. The Employee Welfare Corporation, 「Guidelines on Determining a Cerebral Vessel Disease or a Heart Attack as a Work-related Accident」, 2018-2, Jan. 2018.

In the following section, I will examine concrete examples of laws, guidelines, and judicial rulings related to the burden of proof for fatality from overwork.

B. Related Legal Regulations: Criteria for Determining Fatalities from Cerebral Vessel or Heart Disease as Occupational Accidents Enforcement Decree to the Industrial Accident Compensation Insurance Act, Article 34(3), Attachment 3; Ministry of Employment and Labor Notice 2017-117 (Dec. 2017).



That a worker’s illness (leading to death) was caused by his work-related duties must be verified before determining it as an occupational illness. This burden of proof is divided into three categories:
1. “Sudden and unexpected tension, excitement, horror, surprise or changes in the work environment causing remarkable physiological changes to the employee” means that, within 24 hours before the fatality, the condition of the cerebral vessel or heart disease deteriorated unnaturally, rapidly and noticeably, due to the occurrence of sudden and unexpected incidents or rapid changes in the work environment.
2. “The work burden increases for a short period of time just before occurrence of the fatality due to the volume of work, time involved, intensity, responsibilities, or changes to the work environment, and causes physical and mental fatigue that can noticeably affect the normal operation of blood vessels in the brain or heart” means that, within one week before the fatality, the volume of work or working hours increased by at least 30% over the average week of the previous twelve months (excluding the week before the fatality), or the intensity, work responsibilities or work environment changed so greatly that a normal person would not be able to adjust. Whether this applies to the employee is estimated by considering the volume of work, time involved, intensity, and responsibilities; rest time like holidays and leave; changes in the type of work and working environment; and other factors such as the employee’s age, gender, etc.
3. “A chronic work burden due to volume of work, time involved, intensity, responsibilities, or changes to the work environment causes physical and mental fatigue that can noticeably affect the normal operation of blood vessels in the brain or heart” means that objective confirmation has been made that physical and mental stress continued more often than during general work duties for at least three months before the fatality. In this case, whether “chronic work burden” applies to the employee’s work is estimated by considering the volume of work, time involved, intensity, and responsibilities; rest time like holidays and leave; whether it is shift work or night work or the like; the degree of mental stress; time available for sleep; working environment; and other factors such as the employee’s age, gender, etc. When evaluating the relationship between the working hours/working conditions and the fatality, the following items shall be considered collectively:
(1) If working hours exceeded the average of 60 a week for 12 weeks before the fatality, or 64 a week for 4 weeks before the fatality, the relationship between work and the fatality is considered to be strong.
(2) If the weekly average working hours exceed 52 during the 12 weeks before the fatality, the longer the working hours, the greater the relationship between work and fatality. In particular, when any of the following subparagraphs (factors of weighting workload) apply to the work, it is evaluated that the relationship between work and fatality is strong:
① Work hours not fixed, but change daily;
② Shift work;
③ Work with insufficient off-days;
④ Exposure to harmful working environment (cold, temperature changes, noise);
⑤ Physically-demanding work;
⑥ Frequent business trips with large time lags;
⑦ Work involving significant mental stress.
(3) Even if the working hours do not exceed 52 per week for 12 weeks before the fatality, the relationship between work and fatality increases for tasks where the worker is exposed to a combination of the workload weighting factors in (2) above.

C. Employee Welfare Corporation Guidelines: Substantial Criteria for Recognition of Fatality from Overwork Being Due to an Occupational Illness Employee Welfare Corporation, 「Guidelines on Determining a Cerebral Vessel Disease or a Heart Attack as a Work-related Accident」, 2018-2, Jan. 2018.


1. Sudden incidents or sudden changes in work environment
Sudden incidents and rapid changes in work environment should be of a degree that would reasonably cause tension, excitement, fear, or surprise that could have a significant impact on the normal functioning of the cerebral or heart vessel systems. Therefore, the occurrence of an unexpected accident should be clear in time and place, and should be related to the situation and the occurrence. In other words, when the unexpected situation itself causes a significant physical or mental burden, the fatality usually occurs within 24 hours from occurrence of the incident. Often, however, it takes time for the condition to deteriorate enough to result in a fatality, so even if it is more than 24 hours from the unexpected and unforeseeable occurrence to the fatality, if a causal relationship between the accident and the occurrence can be determined, the fatality can be determined as from an occupational illness. Examples are given below:
① If the worker is directly involved in a major personnel accident or other serious accident related to the business, or is engaged in rescue or accident handling accompanied by an accident;
② In the event of excessive physical or mental stress such as a violent physical confrontation or assault from a supervisor, a colleague or a customer in relation to the work;
③ If the worker has been working continuously for a long time without sleeping.

2. Short-term business stress
In the event of cerebral vessel or heart disease, there is a high possibility that the workload and intensity of work increased rapidly within a short time (one week) before the occurrence of the illness led to a fatality.
(1) Whether or not the workload or work time has increased by at least 30% over the previous 12 weeks (excluding one week before the fatality) is evaluated as follows.
① Quantify the workload within one week before the onset and compare it with the weekly average workload between 2 and 12 weeks before the fatality.
② If the weekly average work time is less than 40 hours between 2 and 12 weeks before the fatality, compare with the change rate based on 40 hours.
③ For night work, 30% will be added to work hours between 10:00 pm and 6:00 am, excluding rest hours.
(2) Whether or not the work intensity, responsibilities, and work environment change to such a degree that it is difficult to adapt to it is evaluated by considering the following points:
① Changes in work responsibility or degree, increase in mental stress, changes to working environment including increased work hours or workload within one week before the fatality;
② Changes in the work burden--whether the worker was able to adapt to the work of the recent week compared to the work of 12 weeks (excluding one week before the fatality).
(3) The burden of work for one week before the fatality is based on, as outlined above, the evaluation of work hours or workload, work intensity and responsibilities, rest hours in terms of holidays or off-days, change of work type or work environment, and adaptation period. Also, the related worker’s age, gender and personal characteristics are considered.

3. Chronic heavy work
"Work Hours" is a different term from "Working Hours" in an employment contract, and refers to the time that a worker is under the supervision of the employer, including time for preparation and clearance. "Meal time" means a time completely outside the supervision of the employer. Even if meal time is guaranteed by the Labor Standards Act or the employment contract, if it is impossible to stop working to eat or rest, it cannot be excluded from work hours.
Work hours are checked first for the associated physical and/or mental burden. Then, other factors such as the existence of shift work, holidays, work schedule, work environment, work intensity, time zone differences, and mental stress are considered.
Work hours are calculated by the number of daily working hours from 12 weeks prior to the fatality to 4 weeks prior to the fatality. Then, the average working hours per week for the entire 12 weeks before the fatality is calculated and evaluated. “Daily working hours” refer to the time work starts to the time work ends minus the time completely outside the supervision of the employer. For work between 10:00 pm and 6:00 am the next day, 30% is added to total working hours. However, for surveillance work such as security guard or similar work, this 30% is not added. Any waiting time that occurs due to the nature of the work, such as intermittent work or driving, is included in the working hours if done under the supervision of the employer.
- If work hours exceed 64 per week for 4 weeks before the fatality, the relationship between work and fatality is evaluated as strong.
- If work hours exceed 60 a week during the 12 weeks before the fatality, the relationship between work and fatality is evaluated as strong.
- If the work hours exceed an average of 52 per week for 12 weeks before the fatality and factors exist that significantly increased the burden of work, the relationship between work and fatality is evaluated as strong.
- Even if the working hours do not exceed 52 per week during the 12 weeks before the fatality, in cases where the worker was exposed to factors that significantly increased the burden of work, a strong relationship is deemed to exist between work and fatality.

D. Guidelines and Court Rulings on Causal Relationships

1. Employee Welfare Corporation Guidelines
The causal relationship between work and illness is not necessarily evident in the medical or natural sciences, but can be verified as the causal relationship from the perspective of legislation and guidelines. In other words, even if there is no direct evidence of the cause of the illness, a causal relationship can be established by considering factors such as worker health at the time of employment and the cause of the illness. Employee Welfare Corporation, 「Guidelines on Determining Cerebral Vessel Disease and Heart Attack as a Work-related Accident」, 2018, p. 5.


2. Views of the court on death from overwork
The term "occupational illness" refers to an illness caused by the work of an employee, so a causal relationship between work and disease must be established—proven by the worker claiming it. However, even if the main cause of the illness is not directly related to performance of the work, if the overwork or stress is a factor in the main cause of the illness – i.e. has caused or exacerbated it – a causal relationship can be determined. While not necessarily evident in the medical or natural sciences, consideration must be given that such a relationship can exist in view of all the circumstances. In cases where an existing illness can be deemed not problematic for normal work, if it can be proven that there was rapid deterioration beyond the natural progress due to the workload, this can also indicate a causal relationship. In all cases, whether there is a causal relationship or not shall be judged based on the health and physical condition of the worker, not simply of the average person. Supreme Court ruling on Apr. 12, 2007, 2006du4912; Supreme Court ruling on Nov. 10, 2005, 2005du8009.


E. Conclusion

In determining whether proof exists for claims that a fatality was the result of overwork, the court generally looks at the work load and mental stress involved in a comprehensive manner. On the other hand, the Employee Welfare Corporation’s Committee on Occupational Illness Judgment has not recognized overwork as the cause of a fatality when 60 hours per week or less is the normal work load. Fortunately, the new Welfare Corporation Guidelines, revised in 2018, will strengthen consideration of various causes of such fatalities. That is, even if there are fewer than 60 working hours per week, additional factors that increase the workload, such as mental stress, shift work, and night work, will be factored into the determination of whether a fatality was caused by overwork or not. There is hope that, in the near future, such stronger consideration will result in greater recognition of this tragic aspect of long working hours.