Office Smoking Rooms in Japan (2026): The Legal Standard, the Subsidy, and the Option of Not Building One

Two obligations, not one

The guidelines distinguish between two legal instruments. The Health Promotion Act imposes a duty on the party with authority over a facility used by many people to take measures preventing unwanted passive smoking. The Industrial Safety and Health Act, aimed at protecting workers, imposes an effort obligation on employers to take measures preventing passive smoking indoors for their workers. In practice this means the facility-level requirements and the employer-level expectations sit alongside each other, and where the employer and the party with authority over the facility differ — a tenant in a multi-occupancy building, for instance — the guidelines ask the employer to coordinate with that party so the Act is complied with.

What a compliant room requires

• Entrance air current of at least 0.2 metres per second flowing inward, maintained with the exhaust equipment running and measured across the opening when the door is open
• Partitioning by walls, ceilings or similar so that smoke does not flow from the room into the rest of the floor
• Exhaust of tobacco smoke to the outdoors or an external space
• Mandatory signage at the room entrance and at the main entrance of the building, stating that the area is for smoking and that under-20s may not enter — and removal of that signage if the room is later removed
• A transitional arrangement exists for pre-existing buildings where outdoor exhaust is not feasible for reasons not attributable to the party with authority: a smoke-removal booth with inward airflow of at least 0.2 m/s, total volatile organic compound removal of 95% or more, and suspended particulate matter in the exhausted air of 0.015 mg/m3 or less
• Maintenance: roughly annually for outdoor exhaust equipment, and roughly quarterly for smoke-removal devices, whose performance drops sharply as filters clog

The guidelines also suggest placing the room at a reasonable distance from work areas and busy thoroughfares, and avoiding areas near the intake of a centrally managed air conditioning system, since smoke could otherwise be distributed through the building. A noren-style curtain narrowing the opening, or a sliding door, are given as practical ways of holding the required airflow with less ventilation volume.

The subsidy for smaller employers

The passive smoking prevention subsidy covers part of the cost of installing a compliant smoking room. Eligibility is limited to employers covered by workers' accident compensation insurance who are small or medium-sized enterprises operating a Type-2 facility under Article 28 of the Health Promotion Act. The subsidy rate is two-thirds of construction, equipment and fixture costs — one-half where the main industry classification is other than restaurants — capped at one million yen, with a per-square-metre limit of 600,000 yen. For fiscal 2026 (Reiwa 8), applications are open with a deadline of 31 January 2027, and the ministry notes it plans to close applications earlier if the budget is exhausted (source: MHLW https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000049868.html). Enquiries go to the health section of the labour standards department of the prefectural labour bureau covering the workplace. Requirements change by fiscal year, so check the official page at the time you apply.

Deciding not to build one

Going fully non-smoking indoors avoids both the capital cost and the ongoing maintenance, and frees the floor area for work. The risk is that the issue simply moves outside — to the building entrance or the surrounding streets — which can generate complaints from neighbours and run into municipal street-smoking rules. The practical answer is to pair the decision with a stated alternative. Where an on-site outdoor area is not possible, identify nearby public smoking areas and name them specifically; you can check what exists around your office on the MottoSuitai map. Municipal street-smoking rules vary widely, so check the local government's official information as well — our guide to municipal street-smoking rules is a starting point.

If you do set up an outdoor area, the guidelines suggest keeping an open-air one as far as practicable from building entrances, windows, air intakes and busy areas such as corridors or break spaces used by non-smokers, and siting it downwind of the nearest entrance where prevailing wind direction is stable.

The organisational side

Alongside the physical decision, the guidelines ask employers to run this organisationally: draw up a plan, name a responsible department, put the state of passive smoking measures on the agenda of the health committee, install and maintain the required signage, provide education and a route for consultation, and state the workplace's passive smoking measures when advertising jobs. They also call for particular consideration for pregnant workers, those with respiratory or circulatory conditions, those working while being treated for illnesses such as cancer, and those sensitive to chemicals — and, for workers aged 20 and over, adjustments to shifts, floor allocation and movement routes so that people who do not want exposure need not pass through smoking areas. This article summarises publicly available MHLW material as of August 2026, does not encourage smoking, and is not a legal or engineering assessment of any particular site.