Overview - EN ISO 21645:2021 (Solid recovered fuels - Methods for sampling)
EN ISO 21645:2021 (identical to ISO 21645:2021 / EN ISO 21645:2021) specifies standardized methods for sampling solid recovered fuels (SRF) from production plants, deliveries, stockpiles and material flows. The standard covers both manual and mechanical sampling techniques and explicitly excludes SRF formed by liquids or sludges (but includes dewatered sludge). It supersedes EN 15442:2011 and is intended to ensure representative, traceable samples for subsequent testing and quality assessment.
Keywords: EN ISO 21645:2021, solid recovered fuels, SRF sampling methods, sampling plan, increment mass, lot definition
Key technical topics and requirements
- Sampling plan development - Define objectives, lot boundaries and sampling frequency before sampling.
- Definition of a lot - Guidance for lots in material flows, vehicles, ships and static stockpiles.
- Number and distribution of increments - How many increments to take and how to distribute them across the lot to achieve representativity.
- Minimum sample and increment mass - Rules and procedures for determining minimum masses required for reliable analysis.
- Sampling equipment and implements - Requirements for manual and mechanical tools, and handling procedures.
- Implementation steps - Clear sequence of actions before, during and after sampling, including handling and storage.
- Precision and heterogeneity - Consideration of SRF-specific heterogeneity (e.g., fibrous or non-granular nature) and the use of a “shape factor” in statistical calculations.
- Normative and informative annexes - Includes templates, worked examples, equipment lists and calculation guidance (sampling plan, increment mass, implementation examples, precision data).
Practical applications and who uses this standard
EN ISO 21645:2021 is used by:
- Laboratories conducting SRF analysis to ensure representative test samples.
- SRF producers and suppliers for quality control and contractual sampling.
- Purchasers and end-users (energy plants, cement kilns) to verify delivered fuel quality.
- Regulators and inspection bodies for compliance checks and audit sampling procedures.
- Logistics operators handling transport by vehicle or ship who need standardized sampling for deliveries.
Practical benefits include improved sampling consistency, reliable test results, reduced disputes in trading SRF and better management of heterogeneous fuel materials.
Related standards
- ISO 18135 - sampling of solid biofuels (related domain).
- EN 14899:2005 and CEN/TR 15310-1:2006 - foundational work referenced in the standard.
- EN 15442:2011 - superseded by this edition.
For implementation, consult the full text of EN ISO 21645:2021 for normative procedures, templates and calculation methods.