The situation detailed in the government’s first-ever white paper on karoshi, or death from overwork — mandated by the 2014 law aimed at promoting efforts to prevent such deaths — points to the need to place effective caps on the working hours of the nation’s company workers. As part of his administration’s much-touted “work-style reforms,” Prime Minister Shinzo Abe reportedly seeks to introduce a legal ceiling on the overtime hours that a worker can clock a month, but there are resistance to tight uniform caps from business circles, particularly among industries that suffer from manpower shortages.

The law, introduced two years ago as a response to the social problem that has been serious since the late 1980s, makes it the state’s responsibility to take steps to prevent death from overwork but does not provide for regulations or penalties to achieve that. It calls on the government to study the situation of heavy workloads that impair the health of company workers and lead them to take their own life.

According to the annual report released last week, 23 percent of 1,743 companies surveyed said they have employees who have worked more than 80 hours of overtime a month — a criteria beyond which a worker’s death can be linked to overwork — including 12 percent that replied that some of their employees clocked more than 100 hours of overtime in a single month. The ratio shoots up to 44 percent among companies in the information and communications business, 40 percent in the research and technology service sectors and 38 percent in trucking and postal businesses.

In fiscal 2015, the deaths of 96 workers due to brain and heart illnesses were recognized as the result of overwork under the labor accident compensation scheme, while suicide and suicide attempts by 93 workers was blamed on mental problems induced by overwork. Other data cited in the report — that 2,159 people killed themselves due at least in part to difficulties they faced on their job over the same period — indicates that the cases that win damages over the labor accident insurance represent only a tip of the iceberg.

Roughly a third of full-time employees polled in the report said they feel high degrees of accumulated fatigue, while 45 percent of them replied that they were not getting enough sleep — citing “long overtime hours” as one of the primary reasons. The ratio of employees who clocked more than 60 hours at work in one week — past the 40-hour limit under the Labor Standards Law — has gradually declined since the peak in the early 2000s to stand at 8.2 percent last year. But the figure rises nearly twice as high among male workers in their 30s and 40s.

The question now is what to make of these data and what actions to take.

The same day the report was released by the government, it surfaced that the suicide last year of a 24-year-old female employee of the major advertisement agency Dentsu Inc. has been recognized as a result of her heavy workload. The woman, who was hired by the company in April 2015, suffered from depression in November after the workload increased sharply. She jumped to her death late the next month. A local labor inspection office confirmed that she had clocked 105 hours of overtime in the month before she developed the mental condition.

A 2000 Supreme Court ruling on a lawsuit filed by the family of another Dentsu employee who committed suicide in 1991 — which was linked to the job’s excessive workload — said a company has the duty to make sure that its employees’ physical and mental health will not be damaged by overwork. That ruling set a judicial standard that recognizes employers’ responsibility for overwork-induced suicides of their workers. However, the number of overworked and over-stressed company employees suffering from depression or taking their own lives has since been on the rise — particularly among young workers, including the high-profile case of a worker at izakaya pub chain operator Watami Co. who killed herself in 2008 after working more than 140 hours of overtime a month. These and the latest case show that the practices of overworking company employees do not go away even as company management is held responsible for damaging their health.

An average worker in Japan is estimated to have worked a total of 1,729 hours in 2014 — roughly 300 hours more than in Germany and France, but lower than in such countries as the United States and South Korea. Since the 1990s, that number has roughly stayed around 2,000 hours among workers not including part-time employees.

The Labor Standards Law sets the limits on work hours to eight hours a day and 40 hours a week in principle. But a labor union-management agreement at each company can effectively get around the Health, Labor and Welfare Ministry standard that limits an employee’s overtime work to 45 hours a month and 360 hours a year.

Abe has vowed to fight the practice of long working hours at Japanese companies as a problem that hinders greater participation of women in the labor force — which he sees as crucial to making up for the decline in the nation’s working-age population. He has included tightening regulations on overtime work in his “work-style reform” agenda. One idea being floated is to place a legal cap on the amount of overtime.

Such a cap would be toothless if it’s set too high. But imposing a tight cap on the amount of overtime hours is likely to face opposition from the business community. Business leaders who took part in the government’s discussions on the issue said they oppose introduction of a uniform cap, saying considerations need to be made for industries that suffer from manpower shortages. But exceptions to the cap on grounds of too few workers will make any such measure ineffective. What also needs to be considered will be ways to prevent businesses from circumventing limits on overtime by getting the employees to work overtime without clocking their hours.

The Abe administration needs to make sure that the regulation to be introduced will be effective enough to protect the health of company workers.