Pursuant to Supplement 21 to UN R54 replacing PSI with kPa to indicate tyre inflation pressures, UN R109 requires updating. This proposal would allow both markings under UN R109 because the life cycle of the carcasses spans several years.

In order to have a Regulation on the retreaded tyres with definitions and provisions structured in the same way of those previously introduced in amendments of “new tyres” Regulations, this amendment:

1. Indicates that for the purpose of this Regulation “tyres” means “pneumatic tyres”, so all the text has been reviewed
2. Introduces a definition of :
   • “retreader” copy based on that “manufacturer” in the tyres regulations
   • Brand name", “Trademark”, “Trade description” and “Commercial name” as defined in the tyre regulations
   • Material manufacturer / material supplier
3. Takes into account the rounding rules (already approved in the other tyre regulations) for the calculation of width and diameter of the tyres
4. Aligns the title and the provisions of the para. 12 related to the names and addresses of Technical Services, Approved Laboratories and administrative Department with their equivalent in the tyres regulations

Addendum from GRRF to include provisions for PSI or kilopascal (kPa) markings and to clarify inflation pressure under the test procedures in the proposal for Supplement 9.