Thermal conductivity is simply the ability of a material to transfer or carry heat. It is measured by the rate of heat transfer through a given source (material). Higher thermal conductivity means that heat transfer will occur at a higher rate. The thermal conductivity in composite materials is anisotropic, which means that heat will be transferred faster along the fiber. The overall thermal conductivity depends to a large extent on the volume fraction of resin and fiber and the tightness of the fiber during heat transfer. It should be noted that the overall design of the composite material structure plays a more important role in the thermal conductivity of the composite material than the fiber itself.

The flammability characteristics of these fibers indicate that they are resistant to high temperatures. Carbon fiber and aramid are often used together as fabrics for firefighting and protective clothing. Matte glass fiber is often used in buildings to improve fire resistance. However, when used in a composite matrix, the temperature of the composite material is limited by the heat capacity of the resin.

The electrical properties of the material are defined by the fiber's ability to conduct current, its resistance to current, and any shielding effects in the electromagnetic spectrum. These characteristics are mainly related to carbon fiber. Because carbon fiber is conductive, it is easy to cause galvanic corrosion to metal parts. In response, industrial applicators bond insulated metal parts to carbon fiber or add a glass fiber layer in the contact area to prevent this from happening. Carbon fiber poses a challenge to aerospace designers and industry because its electrical characteristics must be designed around it and are still being studied.

The glass fiber and Kevlar composite material is almost transparent to radio waves and does not conduct electricity. It is for this reason that Kevlar is often used in transmission towers. (Kevlar coating prevents water absorption)

Chemical resistivity is the ability of a material to withstand exposure to different chemical agents in different pH ranges and how the fiber reacts within a given time range. These have been extensively tested under conditions such as exposing the fibers to water (fresh water and sea water), organic solvents, strong acids, strong bases, weak acids and weak bases.

Carbon fiber is very strong in chemical resistance, and is not very sensitive to any of the above, and it is expected to be strong oxidizing agents. Glass fiber is equivalent to carbon fiber, but has a weaker response to strong alkalis.

Kevlar is not affected by organic solvents or oils, but will degrade in the presence of strong acids, strong bases and some oxidizing compounds. Kevlar fiber should not use chemicals such as bleach. Kevlar can also be degraded by ultraviolet radiation and sunlight.

The overall chemical resistance of the composite material depends to a large extent on the resin used in the composite structure.