This document specifies the material requirements and test methods for prefabricated elastomeric seals for use in flue liners. It also specifies the requirements for evaluation of conformity. These seals are components in flue liners of different materials like metal, plastic, clay, concrete etc. Performance requirements of elastomeric seals in flue liners are covered by the relevant product standards. In the product standards chimney products including seals are tested under operational conditions (e. g. temperature, pressure, mechanical load, flue gas, condensate) to relevant properties such as leakage and deformation. This document covers seals intended for use in both dry and wet conditions. Therefore all seals are tested for functioning under wet conditions. This document does not contain all the requirements necessary for chimneys with the following classification: corrosion resistance class 2 concerning natural wood, 1) corrosion resistance class 3.