Some flexible air ducts are designed with fire-resistant materials or coatings, but not all of them have these properties. It’s essential to check the product specifications and ensure that the duct meets local fire safety codes. Additionally, it’s important to note that flexible ducts should not pass through any fire-resistance-rated assembly, as this could compromise the integrity of the fire barrier. Always consult local building codes and regulations regarding the installation of flexible air ducts in your area.