GRPE-PMP-29-07
PMP Meeting – Draft minutes
08 Jan 2014,
UN Palais des Nations, Geneva
1.0 Welcome & Introductions:
Giorgio Martini opened the meeting and welcomed the participants present as well as
those joining the web conference.
2.0 Review of the existing data on emissions of sub-23 particles (GRPE-29-03)
Giorgio Martini introduced the presentation from JRC reminding the group that this was
a literature survey study to determine the current state of play and knowledge on sub23nm particles. The PMP group had delegated this activity to the JRC at the 27th
meeting.
Also noted that a detailed review and comprehensive discussion had been held at the 28th
PMP meeting.
Barouch Giechaskiel JRC presented the review including additional information on
regeneration emissions (potential renucleation of volatile particles), moped emissions
(artefacts at 3nm which disappeared when evap tube replaced by catalytic stripper, and an
analysis of the uncertainty.
It was recommended to avoid artefacts in measurements of particles < 23nm –by taking
parallel measurement with existing PMP measurements and in the case that significant
numerical differences exist between the measurements, the dilution should be increased
by a factor of 10 for the measurements less than 23 nm as this is usually an artefact.
It was also noted that calibration and calibration materials to be used for measurement
systems covering < 23nm are extremely difficult, especially below 10 nm.
Ms Karlsson noted that if increasing dilution to avoid artefacts, then measuring close to
background levels.
Ms Hosier presented the Technical Secretary summary of the key messages from the 28th
PMP meeting GPRE-29-02
Mr Martini summarised that the main driver for looking at sub-23nm had been the
possibility of an independent nucleation mode – the JRC study had found no evidence for
this on vehicles tested so far.
Mr Giechaskiel noted the only scenario for sub-23nm independent nucleation mode was
with additives and where no soot was present. In the case – but once a filter is used, will
also remove 99% of these particles just as for particles > 23nm.
Mr Cerwinski confirmed that there is simply no other answer – the study of sub 23nm
particles is interesting for researchers and toxicological effects but not appropriate for
legislation with current technologies.
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Mr Steininger noted that whilst there was no urgent need, it was important for the
European Commission that the PMP group should continue to develop a robust method for
measuring sub-23nm in case it became necessary to measure / regulate such particles in
future.
JRC confirmed this was not a short lead time action and the group accepted the request
from the European Commission to continue this work and to develop clear guidelines for
avoidance of artefacts during sub-23nm measurements and to better allow comparison
between different studies
As a consequence of this decision on sub-23nm that it is not an urgent need to revise the
measurement method, it was noted that the PMP group should resume consideration of
particle number measurement during light duty particle filter active regenerations
Agreed to present this issue for GRPE with a slightly modified version of PMP-29-02 rev 1
3.0 Tyre/Road and Brake wear literature study
Giorgio Martini reminded the PMP group that there was a specific request from EU Com to
address non-exhaust emissions also due to GRPE documents from Russia. PMP agreed
to start with a literature review, following which PMP could then decide whether to go
forward, stop or assign to another group.
Document PMP-29-04 (WBCSD tires) was presented. The European Commission noted
that they are more interested in the PN metric rather than PM / PM10. Questions on
resuspension of tyre/road wear particles were also raised.
WBCSD noted that nano-particles were considered in their study – none were detected
either for summer or winter tyres. The measurement system had been challenged with
nano-particles to ensure that if present, they would have been detected.
The chairman asked whether the particles were mainly tyre, or road or a combination of
tyre/road composition. Clarified that the main part of the particles is composed of a
tyre/road combination.
Document PMP-29-05 - the updated JRC non-exhaust particle literature survey was
presented by Mr Grigoratos.
New findings were that increasing vehicle speeds have a tendency to shift the size
distribution to smaller sizes. Different studies have different results – very difficult to
compare owing to different methodologies and measurement conditions as well as lack of
a clear definition of ‘normal driving’
There was some brief discussion of potential tyre wear abatement measures but no clear
conclusions.
The chairman presented a summary of the open questions (PMP-29-06) which the group
agreed to present to GRPE.
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4.0 Any Other Business
Next meetings
Arrangements for the next meetings:
- Agreed that a doodle poll would be launched to establish the next meeting
date (Feb / Mar 2014).
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