72. The expert from Sweden introduced GRPE-65-06, containing information on the introduction of the possibility for national type approval of retrofit emission control system for heavy duty vehicles. The use of these type approved retrofit systems is limited to vehicles designed and approved up to the euro III emission standard (namely city buses) and enables the reduction of pollutant emissions (95 per cent for particles, and 70 per cent for NOX). The effective control the retrofit system shall include indication to the driver if the reduction ratio for NOX is below 50 per cent and if the reagent level in the tank falls below 10 per cent. Replying to a question from the expert from Switzerland, he clarified that the possibility to use vehicles in environmental zones is the main incentive to retrofit them.

73. The expert from Japan introduced GRPE-65-14, containing a summary of the future Japanese policy on motor vehicle emission reduction. He provided details on future emission reduction measures for motorcycles, heavy duty diesel motor vehicles and special motor vehicles (such as non-road mobile machinery) powered by diesel fuel. Speaking about emission reduction from heavy duty diesel vehicles, he specified that the focus will be on the improvement of durability and reliability of NOX after treatment devices and on the use of off-cycle emission measurement. He also elaborated on tailpipe emission reduction measures, current technologies and challenges. Following requests from the expert from the United States and India, he clarified the approach adopted on the measurement of opacity and provided information on Portable Emissions Measurement Systems (PEMS) on heavy duty vehicles.

74. The expert from the Russian Federation introduced GRPE-65-20, containing an analysis, based on studies carried out in the USA and the Russian Federation, on the role of tyre dust with respect to air pollution and health impacts. He invited GRPE participants to share information on the subject and called for the consideration of regulatory action on it.

75. GRPE welcomed the presentation by the experts from Japan, the Russian Federation and Sweden and noted the efforts undertaken in the fields addressed. Agreeing with the suggestion of the expert from Switzerland, GRPE recommended forwarding the document GRPE-65-20 to the Working Party on Braking and Running Gear (GRRF).