ISO 1043-4:2021/PRF Amd 1

Overview

ISO 1043-4:2021/PRF Amendment 1: New Code Numbers for Flame Retardants is an important update to the international standard covering symbols and abbreviated terms for flame retardants used in plastics. Published by ISO in late 2025, this amendment provides revised and expanded coding for various classes of flame retardant chemicals. It serves as a critical reference for manufacturers, engineers, and quality specialists involved in plastics production and safety compliance.

This amendment facilitates clear communication and uniform identification of flame retardant additives worldwide, ensuring improved consistency in technical documentation, testing reports, and regulatory declarations. Maintaining harmonized codes supports global trade and helps ensure material safety in applications where fire resistance is essential.

Key Updates

• Revised Codes for Nitrogen Compounds:

  • 30: Melamine
  • 31: Urea
  • 32: Monomeric melamine-based compounds (melamine salts)
  • 33: Polymeric melamine-based compounds
  • 34: N-alkoxy hindered amine-based compounds
  • 35: Other nitrogen-based compounds
  • 36 to 39: Not allocated

• Updated Codes for Organic Phosphorus Compounds:

  • 40: Aryl phosphates
  • 41: Chlorinated organic phosphorus compounds
  • 42: Brominated organic phosphorus compounds
  • 43: Methyl esters of phosphoric or phosphonic acid
  • 44: Other halogen-free organic phosphorus compounds
  • 45 to 49: Not allocated

These new code assignments replace the previous numbering system, clarifying the classification and enabling more detailed identification of flame retardant types. The amendment is aligned with the broader ISO 1043 series, which standardizes plastic chemical symbols.

Practical Applications

ISO 1043-4 Amendment 1 is highly relevant for:

• Plastic manufacturers incorporating flame retardants in polymer compounds to meet fire safety standards.
• Regulatory compliance teams, who must accurately document material compositions using recognized codes.
• Quality control laboratories performing material testing and certification for fire retardant properties.
• Product designers and engineers ensuring correct flame retardant selection per application requirements.
• Suppliers and distributors standardizing product information sheets and labels for global markets.

By using the updated codes, stakeholders can enhance transparency in supply chains, improve communication across international borders, and support compliance with fire safety legislation and industry standards.

Related Standards

ISO 1043-4:2021/PRF Amd 1 complements several other standards in the plastics and materials domain:

• ISO 1043 series - Standardizes symbols and abbreviated terms for plastics in general.
• ISO 2409 - Methods for testing paint and coatings for adhesion, relevant for flame retardant coatings.
• ISO 4589 - Plastics - Determination of burning behavior by oxygen index.
• IEC 60695 series - Fire hazard testing standards, often applied alongside flame retardant classification.

Additionally, the amendment aligns with broader harmonization efforts under the ISO/IEC Directives and the collaborative framework between ISO and the European Committee for Standardization (CEN).

For more details and to access the full standard, visit ISO’s official website. Standard users should consult their national standards bodies for authorized copies and implementation guidance.