Photo/IllutrationA shop lined with disposable diapers for adults in 2013 in Osaka (Asahi Shimbun file photo)

Plans are afoot in Japan to enable elderly people and their caregivers to dispose of dirty diapers at restrooms more easily using dedicated drainpipes.

With the increasing graying of society, the land ministry, which is in charge of water supplies and sewage systems, is considering ways to reduce the burden of discarding used diapers, including a plan to flush disposable ones down the toilet.

While some of the ministry's plans are expected to become a reality by fiscal 2020 at the earliest, flushing diapers could be problematic, as marine pollution caused by plastics is regarded as a global challenge.

The unconventional plan to flush diapers and collect them through sewage pipes was suggested by a research group comprising women working at a public agency, real estate company, household equipment maker and other businesses.

Arguing in a December 2016 report that diapers are essential not only for babies, but also the elderly, the group states, “Using diapers and allowing aged individuals to relieve themselves on their own are very significant for elderly people as well as the families and society that support such individuals.”

The land ministry quickly started working to realize the group's proposal, as Japan's decreasing population is considered making sewage processing less restrictive, allowing Tokyo to treat diapers in drainage pipes.

The ministry last year set up a panel consisting of college professors and officials from local municipalities and industry associations to develop concrete measures and released a “road map” in March 2018.

In the document, the ministry refers to a plan to crush used diapers and flush them down dedicated drainage pipes.

“If the plan is realized, the burdens on those working at nursing-care facilities will be reduced,” said Masayuki Muraoka, an assistant chief of the ministry’s Sewerage Planning Division. “I'd like it (the diaper-flushing system) to play a role as social infrastructure in a graying society.”

Still, some members of the ministry panel criticized the plan for “possibly blocking sewage pipes and causing water leaks.”

The potential risk of flushed diapers damaging the environment thus also needs to be assessed. As current diapers made of pulp and plastic cannot be decomposed under natural conditions, new diapers would have to be developed that can be released into oceans and rivers.

The ministry thus proposes two alternative plans in the road map to make it easier to treat dirty diapers without flushing them down toilets.

Under the first, excrement and diapers would be separated by dedicated equipment installed in bathrooms and only the excrement would be flushed, while used diapers would be discarded with regular garbage.

Under the second plan, dirty diapers would be crushed and the excrement separated, with only the crushed feces being flushed.

Accelerating efforts to realize such ideas, the ministry will start a verification test by the end of this fiscal year to see whether it is possible to separate and flush excrement, as the first alternative plan appears to be most feasible.

At the ministry’s request, leading electronics maker Panasonic Corp. is developing a prototype of equipment to separate feces so that it can be tested at a care home.

If no problems are reported in the trial, the system will be fully introduced in fiscal 2020. According to the ministry, it will be the first of its kind in the world.


An official of a social welfare corporation in Nagoya expressed appreciation for the ministry’s decision.

“If feces can be separated from diapers, the weight of the diapers can be reduced, lowering the burdens on care workers,” the official said.

At the corporation’s care facility for elderly people requiring special treatment, 20 residents produce up to three 90-liter garbage bags of dirty diapers daily. The heavy diapers with excrement add to the physical burden on staff, according to the official.

“The issues of odor and hygiene will also need to be settled,” the official noted.

More diapers are being used not only at care homes, but also across the nation.

According to the Japan Hygiene Products Industry Association, which comprises diaper makers, the production of diapers for adults increased to 7.8 billion units in 2017, 1.4 times that of seven years ago.

The production is expected to rise further owing to the aging of Japanese society.

The land ministry plans to conduct a questionnaire survey covering 500 care facilities and 4,500 citizens who care for their families so that the number of facilities and people who would like easier ways to discard diapers to be introduced, as well as the number of diapers to be used in the future, can be estimated by prefecture.