Yes, carbon fiber felt welding blankets are fireproof to a certain extent. Carbon fiber itself is known for its high heat resistance and ability to withstand extreme temperatures, which makes it suitable for welding applications. However, the specific fireproof properties of a carbon fiber felt welding blanket can vary depending on the exact composition and treatment of the material.

Generally, carbon fiber blankets are designed to handle high heat exposure, including sparks, molten metal, and welding spatter, but it's important to note that they are typically heat resistant rather than fully fireproof. The degree of heat resistance depends on the temperature rating of the blanket, which can vary, but many carbon fiber felt welding blankets can typically withstand temperatures up to 1,000°F (537°C) or higher.

For the best protection, always check the product specifications and ensure that the blanket meets the requirements for your specific welding or heat exposure needs.