ASTM and ISO are two different organizations that develop and publish standards for various industries. While their standards may cover similar topics, there are some differences between the two organizations and their standards.

ASTM (American Society for Testing and Materials) is a US-based organization that develops and publishes standards for materials and products. ASTM standards are widely used in the US and around the world, and they cover a wide range of topics, including materials testing, construction, and consumer products.

ISO (International Organization for Standardization) is a global organization based in Switzerland that develops and publishes international standards. ISO standards are recognized and used around the world, and they cover a wide range of topics, including quality management, environmental management, and product testing.

When it comes to specific standards, there are some differences between ASTM and ISO standards. For example, the ASTM D2863 and ISO 4589-2 standards both cover the determination of the oxygen index of plastics, but there may be differences in the specific test methods and procedures used in each standard.

Overall, both ASTM and ISO standards are important for ensuring consistency and quality in various industries. It is important to choose the appropriate standard for a specific application and to follow the specific test procedures outlined in the standard to ensure accurate and reliable results.