What materials or products are typically subjected to an oxygen index test?

The Oxygen Index (OI) test is employed to gauge the flammability of materials. This parameter essentially determines the minimum oxygen concentration required in a mixture of oxygen and nitrogen that will just support flaming combustion. The higher the oxygen index, the less flammable the material is.

Typically, materials or products that are subjected to an Oxygen Index test include:

1. Plastics: Plastics are often used in a wide range of products and environments, and it's important to know how easily they can catch fire. This is especially important for plastics used in high-risk environments, such as those used in electrical insulation or construction.

2. Textiles: Textiles used for clothing, upholstery, curtains, and other applications can pose a significant fire risk. Understanding the Oxygen Index can help one choose safer fabrics or use the appropriate fire retardants during manufacturing.

3. Foams: Foams are often used in furniture, mattresses, insulation, and other products. As these can pose a significant fire risk, it's important to understand their flammability.

4. Rubber and Elastomers: Rubber and elastomers are used extensively in various industries including automotive, aerospace, construction, etc. These materials are subject to OI tests to ascertain their flammability.

5. Composites: Modern composites are another class of materials that undergo OI test. The test ascertains that the composite material, which could be used in a wide range of applications from aerospace to construction, has an acceptable flammability threshold.

6. Polymers: It is very important to measure the oxygen index of polymers, especially when they are used in environments where they may be exposed to high temperatures and fire.

Please note that testing varies based on jurisdiction, intended use of materials, and specific industry standards. Consequently, a wide array of materials outside these mentioned ones may be subjected to an oxygen index test based on their usage.