Fire Door

A fire door is a door built to resist fire for a rated time, used in stairwells, boiler rooms, corridors and between buildings. Many fire doors made before the 1980s had an asbestos core, such as asbestos board or millboard, inside a wood or metal skin. Intact doors release few fibers, but drilling, cutting or demolishing them can.

Origin

Fire-rated doors became standard under building and fire codes in the early 1900s, and asbestos was a common core material because it does not burn. Use of asbestos cores declined in the 1970s and 1980s as manufacturers switched to other mineral materials.

Significance in Asbestos Context

Most exposure from fire doors came during installation, hardware work and demolition: carpenters and locksmiths drilling for locks, closers and hinges, workers trimming doors to fit, and demolition crews breaking them apart. The asbestos core is often hidden, so workers may not have known what they were cutting into. A label on the door edge sometimes identifies the maker or rating, which can help with product identification, though labels were often painted over or removed. For building owners, intact fire doors are usually left in place and managed rather than removed. In a claim, fire doors are typically one exposure among many in construction or maintenance work, and coworker testimony and building records help show which doors were installed and who made them.

Example Sentence

As a locksmith in the 1970s he drilled out hundreds of fire doors for new hardware, and the dust from the cores collected in his tool bag.

Related Terms

Asbestos Millboard, Asbestos-Containing Material (ACM), Product Identification, Fiber Release, Presumed Asbestos-Containing Material (PACM), Operations and Maintenance Program

Notes

• Check the edge of an older fire door for a label before any work; do not drill or cut it until it is tested.
• If you installed or worked on fire doors, note the buildings, years and any brand names or labels you remember.