Overview
EN ISO 19337:2024 (ISO 19337:2023) - Nanotechnologies - Characteristics of working suspensions of nano-objects for in vitro assays to evaluate inherent nano‑object toxicity - specifies the key suspension characteristics and applicable measurement methods that laboratories and researchers should consider when performing in vitro toxicity assays. The standard applies to nano‑objects and their aggregates/agglomerates greater than 100 nm and is intended to help determine whether observed toxic effects arise from the tested nano‑objects themselves or from uncontrolled sources.
Key topics and requirements
- Stability of working suspensions
- Monitor changes in secondary particle size (aggregation/agglomeration) and particle concentration during exposure.
- Metal ion concentration
- Measure ionic dissolution from nano‑objects (metal ion release) that can confound toxicity results.
- Culture medium components
- Track relevant medium parameters such as protein content and calcium concentration, which influence corona formation and particle behavior.
- Contamination
- Identify and control contamination (previously endotoxin focus) and other impurities originating from synthesis or handling.
- Measurement methods
- The standard identifies applicable techniques for the above characteristics (see informative annexes) but does not prescribe a single selection strategy - investigators choose methods appropriate to material type, concentration and size.
- Reporting (Clause 6)
- Required reporting items include nano‑object identification and manufacturing details, composition and metallic content, culture medium/serum description, and measurement results. Optional methods are listed for completeness.
- Normative and informative annexes
- Annex A (normative): flow of measurements; Annexes B–E (informative): guidance on stability evaluation, metal ion measurement, culture medium component measurement, and contamination.
Practical applications and users
Who will use EN ISO 19337:2024:
- Toxicologists and in vitro labs seeking reproducible, artifact‑free assays for nanomaterials.
- Nanomaterials manufacturers documenting safety data for regulatory submissions.
- Regulators and risk assessors evaluating evidence on inherent nano‑object toxicity.
- Academic researchers studying nano–bio interactions (corona formation, dissolution, sedimentation).
Benefits:
- Reduces false positives/negatives by identifying confounding sources (ions, protein corona, aggregates).
- Improves inter‑laboratory comparability and data transparency.
- Supports safer product development and regulatory compliance.
Related standards
- ISO/TS 80004‑2 (Vocabulary - Part 2: Nano‑objects) is referenced for terms and definitions used in this document.
Keywords: EN ISO 19337:2024, ISO 19337, nanotechnologies, nano‑objects, working suspensions, in vitro assays, toxicity, characterization, aggregation, metal ion release, protein corona, contamination.