This International Standard specifies requirements for materials for vulcanized solid rubber sealing rings for gaseous fuel (manufactured and natural gas) supply pipes and fittings at operating temperatures up to 50 °C. Some general requirements for the finished joint rings are also given. If there are other requirements for the performance of the finished joint rings, particularly functional tests for the actual sealing system and related pipeline materials, they shall be specified additionally in national standards. This International Standard is applicable to joint rings for all pipeline materials including iron, steel, copper, plastics. In the case of composite sealing rings, depending on their design and after agreement between the manufacturer and the user, the materials used for any rubber parts not coming into contact with gaseous fuel shall not have to comply with the requirement of 5.7 of this International Standard. Joint rings made from cellular rubber materials or with enclosed voids as part of their design are not included in this International Standard.