EN ISO 4589-3:2017

Overview

EN ISO 4589-3:2017 is an internationally recognized standard for testing the burning behaviour of plastics using the oxygen index method at elevated temperatures. Developed by CEN and based on ISO 4589-3:2017, this standard specifies procedures to determine the minimum oxygen concentration that will support combustion of small, vertically oriented plastic specimens under controlled conditions, over a temperature range typically from 40 °C to 150 °C. The results, expressed as temperature index values, provide crucial information about the flammability of plastic materials under conditions simulating potential overheating during service.

This standard is applicable to a variety of plastic forms, including solid, laminated, and cellular materials with apparent densities of 100 kg/m³ or higher. It also offers methods for flexible sheet or film materials when tested with proper support. However, it excludes certain shapes and materials requiring alternative support systems.

Key Topics

• Elevated-Temperature Oxygen Index Testing: Detailed methods for determining the minimum oxygen volume fraction needed to sustain combustion at set temperatures, reflecting real-world overheating risks for plastics.
• Temperature Index (TI): The critical value measured during the test, representing the material's burning behaviour at different service temperatures.
• Flammability Temperature (FT): Procedure for determining the specific temperature at which the plastic will just support flaming combustion in air (20.9% oxygen), valuable for comparative material assessment.
• Applicable Materials: Best suited for self-supporting plastics in vertical bar or sheet form (thickness up to 10.5 mm), including some cellular materials and supported flexible sheets or films.
• Limitations: Not intended for highly shrinkable thin films or material forms requiring external frame support as per ISO 4589-2.

Applications

EN ISO 4589-3:2017 is widely utilized across industries where understanding fire properties of plastics is essential for safety, compliance, and material selection. Typical applications include:

• Product Development: Comparing the fire performance of new plastic formulations or products under elevated temperature conditions.
• Quality Assurance: Ensuring consistent material performance and adherence to safety regulations, especially for plastics used in electrical, automotive, construction, or consumer goods.
• Safety Standards Compliance: Meeting regulatory requirements for flammability in various sectors, particularly where plastics may be exposed to high temperatures during normal use or fault conditions.
• Risk Assessment: Aiding engineers and designers in evaluating fire hazards and selecting suitable materials for applications with critical safety demands.
• Research and Benchmarking: Supporting scientific studies and development of new fire-retardant plastic materials.

Related Standards

For comprehensive evaluation and consistent testing, the following related standards should be considered alongside EN ISO 4589-3:2017:

• ISO 4589-1: Plastics - Determination of burning behaviour by oxygen index - Part 1: General requirements
• ISO 4589-2: Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test
• ISO 13943: Fire safety - Vocabulary
• ISO 3582: Cellular plastics, especially for materials with lower apparent density

These standards work together to ensure a robust and harmonized approach to evaluating the fire behaviour of plastics, supporting both regulatory compliance and enhanced product safety.

By following EN ISO 4589-3:2017, manufacturers, engineers, and quality professionals gain reliable data on the flammability of plastics at elevated temperatures, helping ensure safer products and adherence to international fire safety standards.