ISO 21640:2021

This document specifies a classification system for solid recovered fuels (SRF), and a template containing a list of characteristics for the specification of their properties, enabling trade and use of SRF supporting the protection of the environment.
SRF are produced from non-hazardous waste.
NOTE 1   Untreated municipal solid waste as such cannot be considered SRF. Untreated municipal solid waste can however be feedstock to plants producing SRF.
NOTE 2   Chemically treated solid biofuels that do not contain halogenated organic compounds or heavy metals at levels higher than those in typical virgin material, can be defined as solid biofuels and thus be part of the standard series ISO 17225[1].