What is the ISO standard for limiting oxygen index?

I apologize, but there is no specific ISO standard for a "limiting oxygen index." The ISO standards related to oxygen index testing primarily focus on the determination of the oxygen index value rather than establishing specific limits or thresholds.

ISO 4589-2:2017 is the ISO standard for the "Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test." This standard provides a method for measuring the minimum oxygen concentration required to support the combustion of plastics at ambient temperature conditions. It specifies the apparatus, sample preparation, test procedure, and calculation of the oxygen index value.

The oxygen index value obtained from ISO 4589-2 is an indicator of the relative flammability of a plastic material. However, it does not define any specific limits or thresholds that classify a material as "safe" or "flammable." The interpretation of the oxygen index value and its significance may vary depending on the application, industry, and specific requirements.

It's important to note that different industries or countries may have their own regulations or standards that define flammability requirements for specific applications. For example, the UL 94 standard, although not an ISO standard, is widely used for assessing the flammability of plastic materials used in electrical devices and appliances. It classifies materials into different categories (such as V-0, V-1, V-2) based on their burning behavior under specific test conditions.

When determining flammability requirements or establishing limits for the oxygen index value, it is necessary to consider the specific application, industry standards, and applicable regulations. These limits or requirements may be defined by regulatory bodies, industry associations, or specified in product standards for specific sectors.

Therefore, while ISO 4589-2 provides a standardized method for measuring the oxygen index value, the establishment of limits or thresholds for flammability is typically addressed by other standards or regulations specific to particular industries or applications. It is advisable to consult the relevant industry standards, regulations, or guidelines applicable to your specific context to determine the appropriate flammability requirements.