This document provides two different methods for the quantitative estimation of non-metallic content remaining adhered to the steel wire obtained from the recovery of materials from end-of-life tyres. The pyrolysis method is considered as the reference method while the hydrostatic method is considered as an in situ method. This document includes sample collection and the preparation of representative samples based on a sampling plan for the purpose of their characterization. This document does not cover the operational performance or fitness for use of the materials which are deemed to be a function of agreements between the manufacturer and the customer. This document does not purport to address all the safety concerns, if any, associated with its use. This document does not establish appropriate safety and health practices and does not determine the applicability of regulatory limitations prior to its use.