What Japanese Law Requires of Employers on Secondhand Smoke (2026): Duty vs. Best-Effort Duty

Why "is it mandatory?" has no one-word answer

The guidelines themselves draw the distinction. They describe the Health Promotion Act as imposing "a duty to take measures to prevent unwanted secondhand smoke" on those with management authority over facilities used by many people, and the Industrial Safety and Health Act as imposing "a best-effort duty on employers regarding measures to prevent secondhand smoke among workers indoors" for the purpose of protecting worker safety and health. The stated purpose of the guidelines is to present both sets of requirements together (source: https://www.mhlw.go.jp/content/000524718.pdf). Reading only one law leads to two opposite mistakes: assuming nothing is required, or assuming a total ban is required. Neither is accurate.

One definition matters more than people expect. The guidelines define "indoors" as the interior of a structure with a roof where roughly half or more of the side walls are covered; anything that does not meet this is "outdoors". If you are planning an outdoor smoking shelter, run the design against that definition before building, because a shelter that is too enclosed may count as indoors.

What the Health Promotion Act requires

Article 29(1) prohibits smoking in designated non-smoking areas of specified facilities. For Type-1 facilities (schools, hospitals, child welfare facilities, and government office buildings, per the Article 28 definitions) that means everywhere except a compliant designated outdoor smoking place. For Type-2 facilities — which the guidelines say expressly include ordinary offices, factories and restaurants — it means everywhere indoors except a compliant smoking room (source: e-Gov https://laws.e-gov.go.jp/law/414AC0000000103).

Article 30 then sets out the responsibilities of those with management authority: they must not install equipment intended for smoking in a usable state in a non-smoking area (paragraph 1, a prohibition), and they must endeavour to ask anyone smoking there to stop or leave (paragraph 2) and to take necessary measures to prevent secondhand smoke (paragraph 4). Article 27(1) adds that everyone, when smoking outside a designated non-smoking area, must have regard to the surrounding circumstances so as not to cause unwanted secondhand smoke; Article 27(2) requires managers choosing where smoking is allowed to have regard to placing it where unwanted exposure does not occur (source: same).

The practical checklist

• Confirm your facility category. If you are a tenant, the employer and the person with management authority differ, and the guidelines say you must coordinate with the building owner
• Draw up a promotion plan after assessing conditions at the site, and designate a department or officer responsible for the topic
• Make the status of secondhand smoke measures an item for deliberation by the health committee, and have the occupational physician note it during workplace inspections
• Display the required signage at the entrance of any smoking room and at the main entrance of the facility; remove the signage if the room is removed
• Do not have workers under 20 enter a smoking room for any work — the guidelines state this expressly includes cleaning duties
• Give particular consideration to pregnant workers, those with respiratory or circulatory conditions, those working while treating illnesses such as cancer, and those sensitive to chemicals
• State the measures taken to prevent secondhand smoke at the place of work when advertising jobs or filing job openings

Where a smoking room is built, Annex 1 of the guidelines sets three technical standards: airflow into the room at the doorway of at least 0.2 metres per second, partitioning by walls and ceiling so smoke does not escape, and exhaust to the outdoors. MHLW also runs a subsidy for secondhand smoke prevention measures — its page states a subsidy rate of two-thirds (one-half where the main industry classification is not food and drink service), a cap of one million yen, and a FY2026 application deadline of 31 January 2027, with early closure possible if the budget is reached (source: https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000049868.html). Requirements change by fiscal year, so check the page at the time you apply.

When the building goes smoke-free indoors

A predictable side effect of removing an indoor smoking room is that people step outside instead, which can create friction at the building entrance or in front of neighbouring shops. Checking where the nearest municipal or public designated smoking spots are on the MottoSuitai smoking area map and circulating that information internally is a low-cost way to avoid it. Many municipalities restrict street smoking by ordinance and can impose a fine, so see our guide to street smoking rules by municipality as well. The full picture of facility categories and smoking room types is in our Health Promotion Act explainer.

Where to ask

The guidelines direct subsidy questions to the health affairs division of the Labour Standards Department at the Prefectural Labour Bureau covering your site, and technical questions — including free loan of smoke concentration measuring equipment — to the contact listed on the MHLW website. Facility obligations under the Health Promotion Act are handled by the public health centre with jurisdiction over the site; workplace environment questions go to your Labour Standards Inspection Office. This article is a third-party summary of primary sources as of August 2026, is not legal advice, and does not assess any particular company. Consult a labour and social security attorney or a lawyer for individual matters.