Overview
ISO/TS 21911-2:2022 - Solid recovered fuels - Determination of self‑heating - Part 2: Basket heating tests provides guidance on using basket heating methods to characterize the self‑heating behaviour of solid recovered fuels (SRFs). The technical specification compiles established basket heating test methods, gives practical guidance on their applicability for SRF, and explains how test data can be used to calculate critical conditions in storage (e.g., Critical Ambient Temperature, CAT). Results are intended for quality control and hazard and risk assessments connected with ISO 21912.
Key topics and requirements
- Scope and purpose: Guidance for basket heating tests to assess spontaneous heat generation of SRF; data is specific to sample quality and age.
- Test methods compiled:
- Crossing‑point (basket) method
- Isoperibolic test methods
- Adiabatic hot storage tests
- Reference to UN / MTC Test N.4 and classification criteria (GHS, IMO) and their applicability to SRFs
- Measurement principle: Basket heating tests monitor temperature evolution of a test portion to determine the CAT - an indirect metric of self‑heating potential at higher analysis temperatures (oven temperature).
- Reaction kinetics: Guidance for deriving kinetic parameters from basket tests (e.g., crossing‑point) and using kinetics in storage calculations.
- Sample management: Requirements and guidance for sampling, transport, storage, preparation and disposal to ensure representative results.
- Reporting and annexes:
- Test report content requirements
- Annex A - examples of self‑ignition behaviour for selected materials
- Annex B - worked example for calculating kinetics from crossing‑point tests
- Annex C (normative) - using test data for calculating critical storage conditions
Practical applications and users
ISO/TS 21911-2:2022 is intended for:
- SRF producers and quality control laboratories - to classify batches and monitor self‑heating potential
- Storage and logistics managers - to assess safe storage temperatures and critical conditions
- SRF users and equipment suppliers - to design handling and storage systems that mitigate fire risk
- Consultants, authorities and insurance providers - to perform hazard and risk assessments for SRF facilities
- Research labs - to derive reaction kinetics and compare basket methods with isothermal calorimetry (see ISO 21911‑1)
Practical uses include batch acceptance testing, designing storage ventilation/segregation, informing emergency response plans, and demonstrating compliance with safety recommendations in ISO 21912.
Related standards
Keywords: ISO/TS 21911-2:2022, solid recovered fuels, SRF, basket heating tests, self‑heating, critical ambient temperature, CAT, crossing‑point method, reaction kinetics, storage safety.