The Japanese have no clear term to describe the concept of work-life balance, but they do have one to describe the notion of dying for your company: karoshi.

Karoshi made headlines around the world this year after the suicide of a Dentsu Inc. employee was recognized in October as related to her excessive working hours at the powerful ad agency.

Matsuri Takahashi, 24, jumped from a company dormitory on Christmas Day in 2015 after logging more than 100 hours of overtime the previous month.

The term, often used to describe the Japanese corporate culture of glorifying those who make the ultimate sacrifice for their company, was added to the Oxford English Dictionary in 2002.

With the 2016 Black Company Award bestowed on Dentsu Inc. on Friday to recognize its exploitative and illicit work practices, here is some background on karoshi.

What are the causes of karoshi?

Karoshi is defined as death resulting from work-related stress or fatigue. It can be roughly separated into two types — suicide from mental illness and death from heart or vascular disease.

According to a white paper on karoshi published by the Health, Labor and Welfare Ministry in October, there were 96 cases of death from mental illness and 93 cases of work-related suicide in 2015 that were deemed eligible for worker’s compensation. The paper said 23 percent of all of the companies surveyed said they have employees log at least 80 hours of overtime a month.

Many of the deaths, largely attributed to stroke or heart disease, involved people who worked 80 or more hours of overtime per month.

Among the suicides were 26 cases linked to “changes in job description or quantity,” 17 “special cases” that led to extreme mental stress, and eight cases caused by “extreme harassment, bullying and assault.” And more than half logged over 100 hours per month, including 18 who surpassed 160 hours.

How much overtime would likely cause karoshi?

The labor ministry sets the threshold at 80 hours and considers employee deaths to be “strongly related” to work if that kind of overtime continues for two to six months or exceeds 100 hours in a single month.

According to research published in 2008 by Kenji Iwasaki of the National Institute of Occupational Health and Safety, doing 60 to 80 hours of overtime per month doubles or even triples the risk of triggering brain- and heart-related diseases.

The study also said that working over 80 hours of overtime accompanied by five or less hours of sleep per day will create an extremely high risk of karoshi.

For a case to be formally recognized as karoshi, and for workers’ compensation to be awarded, labor offices must confirm whether the deceased employee worked over 100 hours of overtime a month or exceeded an average of 80 hours of overtime in the past six months, according to a blog post by lawyer Ryo Sasaki of Junpo Law Office.

Sasaki also wrote that the deceased employee’s working environment and mental condition must be investigated.

Isn’t there a law that caps working hours?

The Labor Standards Law states that employees must work no more than eight hours a day and that violators face up to ¥300,000 in fines or up to six months in prison.

However, employees can work overtime if their company and its labor unions, or representatives of more than half of its employees, sign an agreement based on Article 36 of the law, which permits overtime within the limits set by the labor ministry, generally 45 hours a month or 360 hours a year.

But despite the cap, a special provision allows companies to go even further.

According to the labor ministry, nearly 60 percent of large firms had set up Article 36 agreements with special provisions in 2013, with 14.6 percent having an overtime cap above 80 hours.

Following Takahashi’s death, Dentsu promised to set a cap of 65 hours, and Tokyo Gov. Yuriko Koike announced in September plans to have officials of the metropolitan government leave work no later than 8 p.m.

The central government, however, is still in the process of revising the law to institute a definite overtime cap.