There are several materials used for making fire labels that are acceptable to recognized labeling agencies. These include steel, brass, aluminum, and non-metallic. Metal labels are attached by welding, riveting, pop riveting or with drive screws. Non-metallic labels are either die-slit or tamper proof with an adhesive back. Once applied, if any attempt is made to remove the label it will tear apart indicating tampering. Embossed labels are label markings which are stamped directly into the steel, and are also acceptable to the labeling agencies. Fire labels on doors and frames are not intended to survive a fire to prove guilt after the fact. The label is there to indicate that the opening is protected by a properly constructed and applied steel door and frame. Adherence to fire protection requirements must be performed before a fire occurs.