Dr. Dümmler pointed out that the table of p19 is not the latest version, and that the table of the report should be brought in the working document.

The group reviewed the document from the beginning. One line was added for high temperature in the table of page 4.

In paragraph 6.1.1.3. of Annex 17, a debate took place on the initial haze and the necessity to have the same criteria whatever the material.

Concerning the initial haze, Dr. Dümmler was of the opinion that some technologies like the electro-chromatic interlayer or coated glass may start with a haze > 1, i.e. some initial haze measurement would be beneficial.

The Secretariat was of the opinion that the manufacturers would not find interest in that, and that there was no safety concern currently with no initial haze assessment. Yet this could be of some interest in the case of new technologies.

Mr. Terragni presented a scheme asking the reason for a 1% haze. Only Dr. Dümmler was keen to start with an initial haze.

The Technical Services present said that they always measure the initial haze and the final haze and check for a delta haze < = 2% (at least MPA NRW and UTAC do so).

Switchable sidelight and so on may have an initial haze > 1%, and for that purpose some test, equal for all materials, should be proposed.

A debate took place on the value to be given to the initial haze. It was recalled that this is not in the Terms of Reference of the informal group, i.e. plastic windscreen. There was a general agreement that there is a need to address both the initial haze and the final haze values.

The group so far agreed to have different parameters according to the material because of their reactions, except for the optical characteristics because they are considered relevant for all materials (copy/paste from glass).

Conclusion about initial haze: item not to be discussed at this informal group, but Chair to flag the concern at GRSG at his report, for future work.

There was an additional debate about whether the partition should include the windows behind the driver, and whether this should be a 2% haze requirements (buses in the US).

Some experts raised that paragraph 6.1.3.4. of Annex 18 should be improved in order not to repeat the exemptions now included in Annex 21 per document GRSG/2014/15. Same was recognized for annex 14.

The experts discussed the inconsistency in the regulation about the wording and interpretation of the “number of test pieces”. Dr. Dümmler pointed out that this problem can be found in Annexes 14, 16, 17, 18, 19.

Current wording of the regulation permits three different interpretations:

• Samples of 300 × 300 mm,
• samples cut at 300 × 300 mm from real part or
• complete Real part.

The experts agreed for a further change in paragraph 5.2. of annexes 17, 18 and 19 (Secretariat to do the work). The Chair committed to inform GRSG on the necessity to amend annexes 14 and 16 as well for consistency. But the group agreed not to propose changes at the forthcoming GRSG session.