March 2026: Major Advances in Pigment Particle Sizing Standards for the Paint and Colour Industries

March 2026 marks a significant step forward for the Paint and Colour Industries with the publication of two important international standards focusing on dispersion procedures and sedimentation-based particle sizing of pigments and extenders. The new documents—EN ISO 20427:2026 and ISO 20427:2026—deliver harmonized, up-to-date methodologies for sample preparation and measurement processes, fundamentally enhancing quality assurance and product consistency. Whether you work in manufacturing, quality control, compliance, or research, understanding these standards will help you keep pace with technological advances and compliance requirements.

Overview

The Paint and Colour Industries rely on precise pigment and extender characterization to ensure colour consistency, opacity, efficiency, and end-product performance. Accurate sizing and distribution data are vital in everything from decorative paints to advanced coatings for automotive or industrial use. Standards in this sector govern not just the quality of the raw materials, but also methods, results reporting, and inter-laboratory reproducibility.

In this article, you'll learn:

• The scope and structure of newly published standards for pigment dispersion and sedimentation-based sizing
• Key technical updates and procedural best practices
• Compliance needs and business impacts
• Links to access the full standards on iTeh Standards

Detailed Standards Coverage

EN ISO 20427:2026 – Pigment and Extender Dispersion Procedure for Sedimentation-Based Sizing (CEN Edition)

Pigments and extenders – Dispersion procedure for sedimentation-based particle sizing of suspended pigment or extender with liquid sedimentation methods (ISO 20427:2026)

This European-adopted ISO standard provides a comprehensive framework for dispersing pigments or extenders in a liquid medium, specifically tailored for subsequent particle sizing using sedimentation-based techniques. The document details sample preparation strategies that produce reliable, reproducible particle size distribution data independent of the pigment type, utilizing equipment such as ultrasonic probes, shaker devices, or wet jet mills.

Key requirements and specifications:

• Standardized dispersion protocols using ultrasonic (probe or bath), shaker, and wet jet mill techniques
• Procedures tailored to multiple pigment types (e.g., TiO₂, CaCO₃, carbon black, Fe₂O₃)
• Sample preparation steps ensuring minimal agglomeration
• Measurement methods based on sedimentation under gravity or centrifugal forces
• Enhanced guidance on apparatus selection, safety precautions, and energy input protocols
• Updates on normative references and improved clarity in technical terms (aligned with ISO 18451 series and related sedimentation methods)

Who should comply:

• Paint and coatings manufacturers
• Quality assurance and laboratory testing personnel
• Suppliers of raw pigments and extenders
• Research and development laboratories

Practical implications: Manufacturers can achieve higher reproducibility in particle size analysis, critical for regulatory compliance, customer specifications, and formula optimization. Laboratories benefit from clearer procedures for avoiding agglomeration, maintaining sample stability, and improving the accuracy of sedimentation-based measurements.

Notable changes from previous editions:

• Refined definitions for particle hierarchy (primary, aggregate, agglomerate, nanoparticle)
• Updated procedures for calibrating and using ultrasonic and wet jet milling apparatus
• Expanded safety guidance for high-pressure and ultrasonic equipment
• Clearer, harmonized methodology for multi-lab, multi-country implementation

Key highlights:

• Harmonizes European and international testing procedures
• Addresses modern pigment formulations, including nano-sized materials
• Supports advanced quality management and process optimization

Access the full standard:View EN ISO 20427:2026 on iTeh Standards

ISO 20427:2026 – Global Standard for Sedimentation-Based Particle Sizing of Pigments

Pigments and extenders — Dispersion procedure for sedimentation-based particle sizing of suspended pigment or extender with liquid sedimentation methods

Published by ISO, this standard offers a globally recognized procedure for preparing and dispersing single pigments or extenders for particle size distribution analysis using sedimentation techniques. ISO 20427:2026 closely aligns with its CEN counterpart, ensuring harmonization for organizations working across regional boundaries or exporting products.

What this standard covers:

• Methodologies for preparing pigment or extender samples in a liquid phase using standardized dispersion techniques
• Operational guidance on the use of ultrasonic devices, shaker platforms, and high-pressure wet jet mills
• Selection, calibration, and operation of sedimentation-based particle sizing instruments—optical centrifuges, X-ray-based instruments, and field-flow fractionation methods
• Terminology clarification (aligned with ISO 18451 and ISO 80004 series)

Key requirements:

• Strict control of energy input and dispersion parameters (e.g., sonication time, temperature, vessel selection)
• Recommendations for preventing agglomeration and achieving stable, homogenous dispersions
• Sample reporting guidelines for inter-laboratory comparison and regulatory documentation
• Clarified, safety-conscious equipment handling procedures

Target audience:

• International manufacturers and exporters of paints, pigments, and colorants
• Testing and measurement laboratories
• Product developers and regulatory compliance teams

Implementation implications: ISO 20427:2026 promotes uniformity in analytical data, supporting international trade, minimizing disputes, and streamlining certification. The standard's detailed preparation and dispersion instructions help improve result reliability and product quality worldwide.

Notable changes from prior versions:

• Consolidated and clarified technical requirements for laboratory practice
• Updates in references to newer sedimentation and measurement standards (ISO 13317, ISO 13318 series)
• New guidance on field-flow fractionation for nano- and micro-sized pigment analysis
• Improved step-by-step protocols for common and advanced pigment systems

Key highlights:

• Supports accurate pigment sizing across a wide range (nano to micro)
• Internationally harmonized for global supply chains
• Facilitates regulatory and customer-driven documentation

Access the full standard:View ISO 20427:2026 on iTeh Standards

Industry Impact & Compliance

The introduction of these harmonized standards sets a new global benchmark for pigment and extender testing—a shift with tangible impacts across the Paint and Colour Industries:

Business Implications:

• Enhanced comparability of results between suppliers, manufacturers, and clients
• Reduced risk of failed compliance audits or regulatory delays
• Stronger QA/QC frameworks for both routine and R&D laboratories
• Streamlined international certifications and product acceptance

Compliance Considerations and Timelines:

• Organizations should begin aligning laboratory procedures with the updated requirements immediately, with anticipated regulatory adoption timelines varying by sector and region
• Facilities may need to recalibrate or upgrade laboratory instrumentation in line with new apparatus and reporting requirements
• Training for laboratory staff and QA teams is recommended to ensure proper understanding and consistent application

Benefits of Adoption:

• Greater reliability and repeatability in particle size measurements
• Improved product performance through stricter process control
• Transparent reporting and traceability for audits, customer communication, and international trade

Risks of Non-Compliance:

• Potential market access barriers or supply chain delays
• Rejection of analytical results by regulatory bodies or clients
• Increased product recalls or customer complaints

Technical Insights

Common Technical Requirements Across the Standards:

• Use of standardized ultrasonic, shaker, or wet jet milling dispersers
• Sampling and preparation methods designed to minimize agglomeration and ensure a representative, homogenized sample
• Instrument calibration protocols and apparatus selection guidance for reproducible sedimentation-based measurements
• Detailed safety and handling instructions for high-pressure and ultrasonic devices

Best Practices for Implementation:

1. Develop Standard Operating Procedures (SOPs): Adapt the specific dispersion and measurement steps from the standards into customized SOPs for your lab or production facility.
2. Validate Equipment: Ensure that sonicators, wet jet mills, and sedimentation analyzers meet the minimum requirements (e.g., frequency, power ratings, pressure ranges).
3. Staff Training: Provide refresher training on new technical definitions (primary particle, agglomerate, aggregate, nanoparticle) and their impact on measurement reliability.
4. Reference Consistency: Use the same terminology and measurement units as defined in ISO 18451 and related standards.
5. Safety Compliance: Strictly follow safety warnings and handling protocols, especially for high-pressure jet milling and ultrasonication equipment.

Testing & Certification Considerations:

• Regularly verify accuracy using CRM (certified reference materials) and round-robin laboratory participation
• Maintain documentation trails for conformity assessment and external audits
• Reference relevant supporting standards for sampling (ISO 15528), reporting (ISO 9276-1), and new field-flow fractionation methods (ISO 21362)

Conclusion / Next Steps

The release of EN ISO 20427:2026 and ISO 20427:2026 provides the Paint and Colour Industries with a harmonized, scientifically robust foundation for characterizing pigments and extenders by sedimentation-based particle size measurement. Immediate adoption offers competitive advantages in compliance, quality assurance, and international trade.

Key Takeaways:

• Standards provide clarity, reproducibility, and traceability in pigment sizing
• Up-to-date procedural guidance improves safety, accuracy, and efficiency
• Global harmonization benefits manufacturers, QC labs, and supply chains alike

Recommendations for Organizations:

• Review and update internal methods to align with these new standards
• Engage laboratory and quality teams in training and SOP revision
• Access the full standard texts on iTeh Standards for detailed implementation

Stay informed on evolving requirements and best practices by regularly exploring international standards updates.

Explore these standards and more at iTeh Standards: your trusted source for technical specifications and compliance insights.