ISO 6427:2013 - Overview
ISO 6427:2013, "Plastics - Determination of matter extractable by organic solvents (conventional methods)," specifies laboratory procedures for determining the fraction of components in plastics that can be extracted by hot organic solvents near their boiling points. The extractable fraction can include monomers, oligomers, polymers, plasticizers, stabilizers and other additives. The standard describes conventional extraction apparatus and sample preparation, and provides specific solvent and operating-condition recommendations for many common plastics. A single cold‑extraction procedure is included as a special case (Annex B).
Keywords: ISO 6427, extractable matter, plastics testing, organic solvents, Soxhlet extraction, plasticizers, monomers, polymer additives.
Key technical topics and requirements
- Scope & exclusions
- Applies to conventional solvent extraction of plastics; does not apply to food- or drinking‑water contact plastics and is not intended for migration testing.
- Sample preparation
- Remove dust/contaminants; reduce sample size by grinding or cutting without overheating (solid CO2 may be used to control heat); retain specified particle sizes (see Table 1).
- Extraction methods
- Primary methods: Soxhlet extractor (preferred) or equivalent (e.g., Twisselmann-type). Selection of extraction liquid depends on polymer type and purpose (Table 1).
- Annex B provides a cold‑extraction variant for a special case.
- Apparatus & reagents
- Standard laboratory glassware (boiling flasks, reflux condensers), thimbles, wire baskets or glass‑filter crucibles, anti‑bumping granules, rotary evaporator or distillation setup, and vacuum oven for drying.
- Result expression & repeatability
- Results reported as percentage by mass of extractable matter (volatile and/or non‑volatile as applicable). Two determinations minimum; repeat if individual values differ by >5% relative. Method precision not fully established; an approximate ±5% can be expected.
- Test reporting
- Report must reference ISO 6427 and include plastic identification, sample prep details, extraction liquid and time, drying conditions, individual values and mean, and any deviations.
Practical applications - who uses ISO 6427
- Quality-control and R&D laboratories in plastics manufacturing to assess additive content and residual monomers/oligomers.
- Raw-material and compound suppliers for batch verification and specification compliance.
- Independent testing laboratories performing comparative extractability testing.
- Materials engineers evaluating effects of extractable matter on mechanical, electrical or chemical properties.
Note: For food-contact compliance or regulatory migration testing, use the specific methods required by relevant regulations (different from ISO 6427).
Related standards
- ISO 308 (acetone‑soluble matter for phenolic moulding materials)
- ISO 1875 (plasticized cellulose acetate - extractable matter)
- ISO 1773, ISO 383, ISO 565 (laboratory glassware and sieves referenced for apparatus and sample sizing)
ISO 6427 is a practical reference for conventional solvent extraction of plastics when assessing extractable constituents and their likely influence on product performance.
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