Passed in 1992 and most recently amended in 2008, the NOx and PM law sets emissions parameters in 196 communities that had been significantly affected by these pollutants. It applies to commercial cargo vehicles (trucks, vans, and buses), as well as special purpose motor vehicles and diesel passenger cars.
NOx and PM emission limits
Ministry of the Environment (MOE)
Automotive NOx and PM Law, 2007 amendment
196 communities in the Tokyo, Saitama, Kanagawa, Osaka, and Hyogo Prefectures
In 1992, to cope with NOx pollution problems from existing vehicle fleets in highly populated metropolitan areas, the Ministry of the Environment (MOE) adopted the “Law Concerning Special Measures to Reduce the Total Amount of Nitrogen Oxides Emitted from Motor Vehicles in Specified Areas“, called in short “The Motor Vehicle NOx Law.” The regulation designated a total of 196 communities in the Tokyo, Saitama, Kanagawa, Osaka, and Hyogo Prefectures as areas with significant air pollution due to nitrogen oxides emitted from motor vehicles. Under the Law, several measures had to be taken to control NOx from in-use vehicles, including enforcing emission standards for specified vehicle categories.
The regulation was amended in June 2001 to tighten the existing NOx requirements and to add PM control provisions. The amended rule is called the “Law Concerning Special Measures to Reduce the Total Amount of Nitrogen Oxides and Particulate Matter Emitted from Motor Vehicles in Specified Areas,” or in short the Automotive NOx and PM Law. The amended regulation became effective starting in October 2002.
It was last amended on 19 December 2007 and became effective on 1 January 2008.
The NOx and PM Law introduced emission standards for specified categories of in-use highway vehicles including commercial goods (cargo) vehicles such as trucks and vans, buses, and special purpose motor vehicles, irrespective of the fuel type. The regulation also applied to diesel powered passenger cars (but not to gasoline cars).
In-use vehicles in the specified categories must meet 1997/98 emission standards for the respective new vehicle type (in the case of heavy duty engines NOx = 4.5 g/kWh, PM = 0.25 g/kWh). In other words, the 1997/98 new vehicle standards could have been retroactively applied to older vehicles already on the road. Vehicle owners had two methods in which to comply:
- Replace old vehicles with newer, cleaner models
- Retrofit old vehicles with approved NOx and PM control devices
Vehicles have a grace period, between 9 and 12 years from the initial registration, to comply. The grace period depends on the vehicle type, as follows:
- Light commercial vehicles (GVW ≤ 2500 kg): 8 years
- Heavy commercial vehicles (GVW > 2500 kg): 9 years
- Micro buses (11-29 seats): 10 years
- Large buses (≥ 30 seats): 12 years
- Special vehicles (based on a cargo truck or bus): 10 years
- Diesel passenger cars: 9 years
Furthermore, the regulation allows postponement of its requirements by an additional 0.5-2.5 years, depending on the age of the vehicle. This delay greatly complicated the implementation of the Tokyo diesel retrofit program by significantly expanding the number of older vehicles failing the local in-use emission standard.
The NOx and PM Law was enforced in connection with Japanese vehicle inspection program, where non-complying vehicles cannot undergo inspection. This, in turn, may trigger an injunction on the vehicle operation under the Road Transport Vehicle Law. This, in turn, may trigger an injunction on the vehicle operation under the Road Transport Vehicle Law, although non-compliant vehicles may still be used within designated areas provided they are registered elsewhere.