A system to provide sufficient downtime between work shifts to prevent "karoshi" deaths from overwork is only being implemented at 3.7 percent of companies surveyed by the labor ministry.

The government set a goal of raising the figure to 10 percent or more by 2020, but few companies have incorporated the system into their employee working conditions.

The introduction of a work shift interval system is seen as a trump card to prevent deaths from a lack of rest and sleep due to grueling work hours.

But the survey results released Oct. 29 showed the percentage of companies that had adopted the system as of January failed to reach 5 percent, although it was roughly double the figure of a year earlier.

The labor ministry contacted companies with 30 or more employees and obtained valid responses from about 4,000.

About 80 percent of companies surveyed said they are neither planning nor considering to adopt the system. The survey asked reasons with multiple answers allowed. Among the most cited reasons, around 19 percent answered they did not know about the system, and some 11 percent said its introduction would interfere with daily operations due to a labor shortage or heavy workloads.

About 53 percent of the respondents were reluctant to adopt the system on grounds they do not feel the need to do so since their employees rarely work overtime. The labor ministry is urging such companies, as well as other firms, to introduce the system if they have busy periods when employees are likely to put in long work hours.

In April, the government required companies to make efforts to introduce the system by revising the law for improving working hour arrangements as part of its work style reforms.

The labor ministry’s outline plan for prevention of karoshi, which the Cabinet approved in July 2018, includes a goal of raising the percentage of companies which adopted the system to 10 percent or more by 2020.

The government also initiated a program to provide small and midsize companies that set a minimum interval between work shifts with subsidies not exceeding 1 million yen ($9,146) to cover the costs of introducing the system.

However, a labor ministry official handling the issue said achieving the target by 2020 would be difficult.

Japan lags behind other countries, such as members of the European Union, in introducing the system. EU countries are obliged to give workers a rest period of at least 11 consecutive hours between working shifts, but the labor ministry guidelines do not specify appropriate rest hours.

“In Japan, commuting hours for workers, especially those working in the Tokyo metropolitan area, are long, so they should take a rest of at least 11 hours,” says lawyer Hiroshi Kawahito, who is well-versed in karoshi issues. “Even at companies which adopted the system, some employees bring their work home because their workload still remains heavy. So, companies need to check whether employees are taking a rest even after introducing the system.”