I've worked in the industry since dirt was made and never heard about asbestos being an ingredient in the doors. I know it's fiber glass but have anyone heard of the older box cut out or other cut outs having doors with asbestos?
Mahalo...
Not asbestos as far as I know. The old ones used a material known as "bone fiber" as the arc extinguishing media. It was a cloth material that was saturated with chemicals that would emit gasses and water vapor to extinguish the arc.