Bangkok: Bangkok has partnered with the Pollution Control Department to introduce new black smoke standards for diesel vehicles in an effort to combat PM2.5 dust pollution, starting November 1st. Mr. Pornprom Vikitset, Advisor to the Governor of Bangkok and Bangkok's Sustainability Officer, highlighted the significant health issues posed by PM2.5 dust, primarily stemming from vehicle exhaust emissions. The incomplete combustion of diesel, due to factors such as low-quality fuel and engine inefficiencies, has been identified as a major contributor to black smoke emissions.
According to Thai News Agency, the Pollution Control Department has proposed a reduction in the allowable black smoke emissions from diesel vehicles, tightening the standard from a maximum of 30% to 20%. This change, set to take effect on November 1, 2025, was announced in the Royal Gazette on September 29, 2025. The new regulation specifically targets older vehicles that do not meet the Euro 5 standards, aiming to cut down the production of PM2.5 particles from engine combustion.
Vehicles found in violation of this new standard will be marked with "Temporarily Prohibited for Use" stickers and will need to be repaired within 15 days, a decrease from the previous 30-day period. After the 15-day window, officials will reassess the vehicles to determine compliance. If the vehicle meets the new standards, the temporary ban will be lifted; otherwise, a complete ban will be enforced, necessitating further repairs.
To comply with the new regulations, owners of older diesel vehicles (Euro 1-5) are encouraged to take several actions to reduce black smoke emissions. These include regular maintenance activities such as cleaning or replacing air filters, changing fuel and oil filters, adjusting fuel pumps, timing injection correctly, and ensuring fuel injectors are functioning properly. These measures not only aim to address the root causes of black smoke emissions but also contribute to reducing PM2.5 pollution in the city.