47. Building on the presentation contained in GRPE-66-21-Rev.1, the PMP Chair summarized a proposal containing the terms of reference for the activities of the group (GRPE-66-30) and presented an overview of the related work programme. He explained that the scope of the terms of reference was intentionally kept as wide as possible (for example, non-exhaust particle emissions were also included) while the proposed work programme was limited to the items that were deemed to have the highest priority. The mandate for the work of the group on Particle Measurement Programme should be completed by June 2017. He added that addressing emerging issues such as the development and validation of new test procedures (such as particle number measurement systems compatible with Portable Emission Measurement Systems (PEMS)) and the consideration of issues like tyre/brake wear would require an extension of it.

48. The expert from India asked about the possibility to consider engines running on gaseous and blended fuels. The PMP Chair clarified that emissions from all engines types are already within the PMP group scope. Replying to a second question, on the possibility to analyse the particle nature and their danger for health, the PMP Chair explained that tackling these tasks would require not only specific equipment and expertise, but would also involve significant scientific challenges. Responding to comments and questions by the Russian Federation and CLEPA on tyre and brake wear, he confirmed that, even if these subjects were within the PMP scope, the current activities could concentrate mainly on early steps like a literature review.

49. GRPE acknowledged the work progress and approved the updated PMP terms of reference, as reproduced in Annex V, confirming the broad definition of the scope and agreeing with the priorities proposed by the PMP Chair, understanding that work cannot be conducted, at the same time, on all the issues.