Regulations
Environmental regulations and agencies in Thailand
A collection of the official links Thai factories use most for air pollution: the agencies responsible, online systems, the main laws and the Ministry of Industry's factory air emission notifications. Links and legal status last checked on 12 November 2026. Most of the linked pages and documents are in Thai; titles below are English descriptions.
Agencies and online systems
| Agency / system | What it is for | Link |
|---|---|---|
| Department of Industrial Works (DIW) | Factory operating licences (Ror Ngor 4) and regulations under the Factory Act | diw.go.th |
| DIW — environmental regulations | Notifications on air, water and waste standards and environmental personnel | Environmental regulations page |
| Documents for a factory licence application | List of documents to submit, including treatment-system drawings and calculations | Download (DIW) |
| POMS (Pollution Online Monitoring System) | Real-time stack emission data from factories with CEMS | poms.diw.go.th |
| Pollution Control Department (PCD) | Air quality standards, pollution control zones and the complaints system | pcd.go.th |
| PCD — laws and standards | Ministry of Natural Resources and Environment notifications and pollution control zone notices | PCD laws page |
| Air4Thai (PCD) | Hourly air quality and PM2.5 readings across Thailand | air4thai.pcd.go.th |
| Stack emission measurement manual, volume 1 (PCD) | Locating sampling ports and determining stack gas velocity and flow rate | |
| Office of Natural Resources and Environmental Policy and Planning (ONEP) | Environmental impact assessment (EIA) | onep.go.th |
| Smart EIA Plus (ONEP) | Search approved EIA reports | eia.onep.go.th |
| Royal Thai Government Gazette | Official texts of laws and notifications in force | ratchakitcha.soc.go.th |
| Central Law Portal | Draft laws open for public comment | law.go.th |
| Council of Engineers | Verify a controlled-engineering professional licence | Licence check |
| Federation of Thai Industries (FTI) | Private-sector body with an environmental management industry group | fti.or.th |
Main laws
| Law | How it relates to air pollution work | Link |
|---|---|---|
| Factory Act B.E. 2535 (1992), as amended | The parent law for factory licences and stack emission standards | DIW |
| Enhancement and Conservation of National Environmental Quality Act B.E. 2535 (1992) | Emission standards for point sources, pollution control zones and EIA | PCD |
| Ministerial Regulation on safety standards for hazardous chemicals B.E. 2556 (2013) | Issued under the Occupational Safety, Health and Environment Act B.E. 2554 (2011); covers chemicals in workplace air | PDF (copy of the Gazette text) |
Frequently used factory air emission notifications (Ministry of Industry)
| Notification | Dated | Link |
|---|---|---|
| Limits for contaminants in air discharged from factories, B.E. 2549 (2006) (general standards) | 31 Oct 2006 | |
| Limits for smoke in air discharged from factory boiler stacks, B.E. 2549 (2006) | 31 Oct 2006 | |
| Limits for contaminants from boiler and heater stacks of factories in Bangkok, B.E. 2569 (2026) | 12 Feb 2026 | |
| Requirement to install special equipment to report stack air emissions, B.E. 2565 (2022) (CEMS) | 1 Apr 2022 | |
| Amendment (No. 2) to the above notification, B.E. 2567 (2024) | 8 Aug 2024 | |
| Requirement for factories in Bangkok to install special equipment to report stack air emissions, B.E. 2569 (2026) | 12 Feb 2026 | |
| Limits for contaminants in air discharged from power plants, B.E. 2567 (2024) | 11 Feb 2025 | |
| Reporting of pollutant types and quantities (Ror Wor), B.E. 2558 (2015) | 21 Aug 2015 | |
| Ministerial Regulation on odour standards in air from factories, B.E. 2568 (2025) | 27 Mar 2025 | PDF (Gazette) |
| Control of volatile organic compound emissions from storage tanks, B.E. 2565 (2022) | 2022 | |
| Registration of water or air pollution treatment system operators, B.E. 2569 (2026) (DIW notification) | 28 Jan 2026 |
Industry-specific standards, such as for cement, glass, oil refineries, gas separation plants, steel bars and flares, are on the DIW environmental regulations page.
Laws and measures to watch
- Draft Clean Air Management Act — not yet in force; under consideration by a joint parliamentary committee (Thairath, 10 Nov 2026, in Thai).
- Bangkok is a pollution control zone from November to March each year, under a 2025 notification of the National Environment Board (Thansettakij, 17 Sep 2025, in Thai).