Remaining Open Issue for REC (informal document GRPE-66-08)

The chairman had circulated a memo giving background information on the NO2 requirement and on the need for a decision on the permissible level of NO2 for Class II systems. He summarised the air quality and legislative issues. The NO2 limit of 20% proposed by Germany had been supported by Sweden and the Netherlands.

Galey said that the level 00 requirements of a 50% min. PM reduction with a 30% max. NO2 increase would permit the use of partial filters which many considered to be ineffective. A 20% NO2 limit at stage 01, as had been proposed, would then make it difficult to approve the very effective full-flow CRT-type filters. He viewed these two extremes as inequitable. He said that there is limited data available on the proportion of NO2 on the WHTC, partly because there is limited test-bed availability due to the introduction of Euro VI and suggested that there should initially be a less stringent NO2 limit at the 01 stage which could then be amended in the light of experience.

Eberhardt felt that the 50% reduction in level 00 is no longer state-of-the-art. Germany could agree to a 30% NO2 increase for the 00 series providing it was reduced to 20% for level 01, which would be the important stage for Europe.

The lack of data to support the proposed 20% level was discussed, with concerns from some participants that this level would exclude the most effective systems. The possibility of too lenient a level forcing additional actions in EU Member States was noted and the possibility of moving from 30% to 20% over a period of time was considered. It was also suggested that there are promising systems for meeting the 20% max NO2 increase.

After further discussion, the chairman said that he would propose to GRPE a 30% cap on the NO2 increase for level 00 and a 20% cap for level 01. Berger supported this proposal. He suggested that stakeholders could use the time before presentation of the formal 01 proposal to provide results on the WHTC.

Galey then suggested increasing the level 00 requirements from 50 to 70% to exclude partial filters whilst still permitting CRT-type systems. Following a break for informal discussion, it was concluded that it would not be feasible to change such an already-agreed parameter at this late stage, when the formal submission had already been made to GRPE.

Galey then suggested that there should be 3 levels of the Regulation, with the 01 level staying at a 30% cap with the 90% PM reduction and a 3rd stage with 20% NOx cap and 90% PM reduction. The chairman considered that this could be discussed but would not be a solution he favoured. He asked for the views of other contracting parties on the issue of NO2. India said that they would look at how to adopt the REC in India, because they do not have 10 ppm sulfur fuel which would be needed for continuously-regenerating filters and they need to consider the training of retrofitters. Korea said that NO2 is also an important issue in Korea, particularly in metropolitan areas. They do not currently have NO2 regulations, but will be reviewing the UNECE-REC Regulation for the Korean situation.