13. Taking into account the previous discussion and adoption in principle of informal documents GRSP-77-03, GRSP-77-04 and GRSP-77-05 under agenda item 24 (b) (see paragraph 48), GRSP adopted these three informal documents together with informal document GRSP-77-33-Rev.1 (as reproduced in annex III to the session report) and requested the secretariat to submit them as proposals for supplement 6 to the 08 series of amendments, supplement 2 to the 09 series of amendments and supplement 2 to the 10 series of amendments to UN Regulation No. 16 to the November 2025 sessions of WP.29 and AC.1.

48. The International Whole Vehicle Type Approval (IWVTA) Chair informed GRSP that following the adoption by AC.1 of an amendment to Schedule 5 of the 1958 Agreement during its March 2025 session, IWG IWVTA had prepared amendments to delete the Unique Identifier (UI) descriptions from UN Regulations Nos. 16 (informal documents GRSP-77-03, GRSP-77-04 and GRSP-77-05), 22 (informal documents GRSP-77-06 and GRSP-77-07), 44 (informal document GRSP-77-08) and 129 (informal documents GRSP-77-09, GRSP-77-10, GRSP-77-11 and GRSP-77-12). He suggested that it would be desirable to implement these amendments in conjunction with other revisions at an appropriate time. The expert from the Kingdom of the Netherlands supported the amendments and reiterated the suggestion to wait until other amendments were needed for each of the affected regulations in order to group them with these amendments and avoid a proliferation of supplements. GRSP adopted all ten informal documents in principle and agreed to wait to convert them into working documents until other amendments to the concerned UN Regulations were needed.

12. The expert from the Kingdom of the Netherlands introduced informal document GRSP-77-33-Rev.1, which superseded ECE/TRANS/WP.29/GRSP/2025/3. He explained that the final drafting of the amendment kept dry quartz as the requirement in the test description and then offered talcum as an alternative way of fulfilling this requirement. He also clarified that the relative softness of talcum did not lower the stringency of the test, as this test was measuring dust intrusion, not durability and that it should be up to type approval authorities, to decide which substance to use in the test. The expert from CLEPA supported the proposal and announced that they were carrying out tests to assess the difference between the two substances and would bring the results to the next GRSP session.

13. Taking into account the previous discussion and adoption in principle of informal documents GRSP-77-03, GRSP-77-04 and GRSP-77-05 under agenda item 24 (b) (see paragraph 48), GRSP adopted these three informal documents together with informal document GRSP-77-33-Rev.1 (as reproduced in annex III to the session report) and requested the secretariat to submit them as proposals for supplement 6 to the 08 series of amendments, supplement 2 to the 09 series of amendments and supplement 2 to the 10 series of amendments to UN Regulation No. 16 to the November 2025 sessions of WP.29 and AC.1.