56. The representative from the European Commission, Chair of the IWG on PMP, introduced GRPE-89-37 giving a status report of the activities of the IWG on PMP. The representative of OICA asked whether the IWG on PMP had any discussion on emission limits for brake emissions of heavy duty vehicles. The Chair of the IWG on PMP confirmed this had not yet been discussed.

57. The representative of Germany thanked the IWG on PMP for the update and supported the good work performed by the IWG.

58. The secretariat requested further clarifications on the development for forthcoming amendment to UN GTR No. 24 and also about the method selection for non-friction braking coefficients. The Chair of the IWG on PMP wished to submit the final text for inclusion of a methodology to determine vehicle-specific non-friction braking coefficients via a written procedure following this session of GRPE. He also clarified the latest text indicated OEMs could select between Table 5.1. or Annex C value for non-friction braking coefficients.

59. The representative of the European Commission, Chair of the IWG on PMP, introduced GRPE-89-27 proposing revised terms of references. The representative of the Netherlands asked whether health effects of brake / non-exhaust particulates was considered in the activities of the IWG on PMP. The Chair of the IWG on PMP explained the IWG did not have the appropriate expertise and focused on emissions for the time being. He welcomed inputs and/or relevant literature on the topic on adverse health effect of non-exhaust emissions.

60. The representative of the Netherlands asked about the best place to discuss such topics. The Chair confirmed GRPE is an appropriate place and asked GRPE about any other parties willing to support activities on this topic. The representative of the Netherlands confirmed their willingness to introduce the topic in more details at the next session of GRPE.

61. The representative of France confirmed their interest in the activity of heavy-duty brake particulate emissions, and asked further information about potential sponsors for the activities and if the authorization process already started to WP.29/AC.3. The Chair of the IWG on PMP suggested the EU might be in a position to sponsor the activity and that the request for authorization will be drafted once the revised ToRs are adopted by GRPE.

62. The representative of the US informed GRPE on the content of the Notice of Proposed Rulemaking recently released in the US, where a limit of 0.5mg/mi has been proposed as a limit for tailpipe emissions, including some testing at -7°C. He also confirmed the US was performing tests on European vehicles under EU and US test procedures and that he would consider briefing GRPE on the most prominent results at forthcoming session of GRPE.

63. GRPE adopted GRPE-89-27 as revised ToRs for the IWG on PMP.

64. The representative of France, co-Chair of the Task Force on Tyre Abrasion (TFTA), introduced GRPE-89-35. The representative of OICA requested additional information about the check of consistency of reference tyres. The co-Chair of the of the TFTA explained that definitions for reference and candidate tyres were needed, and that an ASTM definition had been agreed.

65. The representative of OICA asked whether such definition was only about tyre size. The co-Chair of the of the TFTA mentioned tyre size, thread depth, shape was all part of the information needed for a comprehensive ASTM description.

66. The Chair requested the secretariat to include a dedicated agenda item for the TFTA for the next session of GRPE.