ISO 21640-2021 PDF

Full title and description

ISO 21640:2021 — Solid recovered fuels — Specifications and classes. This International Standard specifies a classification system for solid recovered fuels (SRF) and provides a template listing characteristics for specifying SRF properties to support trade and environmental protection.

Abstract

The document establishes classes and a specification template for solid recovered fuels (SRF) produced from non‑hazardous waste. It enables consistent specification, classification and communication of SRF properties (composition, calorific value, contaminants, sizing, moisture, etc.) to facilitate their safe and efficient use as fuels while supporting environmental protection. The standard notes that untreated municipal solid waste as such is not SRF and refers to the ISO 17225 series for chemically treated solid biofuels.

General information

• Status: Published (International Standard).
• Publication date: May 11, 2021 (edition 1, 2021).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.160.10 (Solid fuels); developed under ISO/TC 300.
• Edition / version: Edition 1 (2021).
• Number of pages: 26 pages in the ISO publication (note: national/adopted versions and published PDFs can show different page counts — e.g., some EN/BSI publications list 36 pages).

Scope

ISO 21640:2021 specifies a system to classify solid recovered fuels (SRF) and provides a specification template containing a list of characteristics to be reported for SRF. It applies to SRF produced from non‑hazardous waste streams and is intended to standardize how SRF properties are specified for trade and utilisation while supporting environmental protection. The standard explicitly excludes untreated municipal solid waste as SRF (although such waste can be feedstock for SRF production).

Key topics and requirements

• Classification system for SRF classes based on key fuel properties (e.g., net calorific value, chlorine/halogen content, heavy metals, moisture, ash content, particle size ranges).
• Specification template listing required and optional characteristics to communicate SRF quality for trade and use.
• Requirements and definitions clarifying which materials qualify as SRF (produced from non‑hazardous waste) and exclusions (untreated MSW).
• Guidance to support environmental protection by flagging contaminants and compositional limits relevant to combustion and recovery applications.

Typical use and users

Primary users include SRF producers and processors, waste‑to‑energy plant operators, cement and industrial fuel users, fuel traders, quality laboratories, regulators and certification bodies. The standard is used to prepare sale/specification documents, to classify shipments, to harmonize quality control and to support permitting and environmental compliance.

Related standards

ISO 21640 references and is related to the ISO 17225 series (solid biofuels) for certain chemically treated solid biofuels and aligns with existing regional/national standards for recovered fuels. In some markets the EN/BS adoptions (for example BS EN ISO 21640 and UNE‑EN ISO 21640) reflect this ISO document and replace or update earlier documents such as EN 15359. Users should consider national adoptions and sector‑specific standards alongside ISO 21640.

Keywords

solid recovered fuels; SRF; fuel classification; fuel specification template; waste‑derived fuel; waste‑to‑energy; calorific value; chlorine; heavy metals; moisture; ash content.

FAQ

Q: What is this standard?

A: ISO 21640:2021 is an International Standard that defines specifications and classes for solid recovered fuels (SRF), including a template of characteristics for specifying SRF properties to enable trade and environmentally informed use.

Q: What does it cover?

A: It covers a classification system for SRF, a template of characteristics to be reported (composition, calorific value, contaminants, moisture, particle size, etc.), definitions of SRF and notes on exclusions (e.g., untreated municipal solid waste).

Q: Who typically uses it?

A: SRF producers, fuel traders, industrial fuel users (cement, power, CHP), waste processing and recycling companies, testing laboratories, regulators and certification bodies use the standard for specification, quality control and compliance.

Q: Is it current or superseded?

A: ISO 21640:2021 is the first edition published in 2021 and is current as the ISO International Standard on SRF classification (users should check for any later amendments or national adoptions).

Q: Is it part of a series?

A: It is related to the ISO solid biofuels series (ISO 17225) for certain chemically treated solid biofuels; it also interacts with regional/national recovered‑fuel standards and EN/BS adoptions.

Q: What are the key keywords?

A: SRF, solid recovered fuel, fuel specification, classification, waste‑derived fuel, calorific value, chlorine, heavy metals, ash, moisture.