Chipped material in all electrical boxes a cause for concern?

Question

I live in a condo that was built in 1980. I've replaced a few switches and outlets around the unit. Every single electrical box is filled with chips of this material, and the wires are coated (either a little or completely) with what I assume is sprayed-on primer that leaked into the boxes.

The material was already at the bottom of every box when I removed the cover plate.

I have limited experience with building materials, but it looks like plaster - it crumbles like chalk under pressure, snaps if broken and dissolves in water.

Questions:

1. Is it likely to be plaster, or some kind of fire retardant or insulation that was once in fashion?

2. Should I clean out the existing electrical boxes? Most haven't been opened since the unit was built.

3. How did they get there? Is it just laziness on the part of the original electricians?

I know this is a bit vague, let me know what other detail I can add.

Answer 1

Gypsum and joint compound aren't combustible. It's not a problem. Clean it out if it bothers you.

This has nothing to do with laziness. It has to do with efficiency of the process, which often looks like this:

• Framing carpenters or masons put up the walls
• Electricians "rough in" the conduit, boxes, and wiring
• Drywall hangers put up the sheets and tapers and painters finish the walls
• Flooring installers do their thing
• Electricians come back and close up their work, adding devices and cover plates

At that point, it's not practical for electricians to carry a vacuum cleaner around with them. Nor is it important, really. They need to shave extra drywall mud from around the boxes--it gets smeared over them when the tapers do their work. It would slow progress down considerably if they had to clean out each of the hundreds or thousands of boxes on a job. No one would be happy with that or the cost it would incur.

Answer 2

Those are just flakes of drywall compound. They are inert and not flammable. That quantity presents no problem at all.

In the course of working in the boxes, you can clean them out, but I'd never deliberately open a box just to clean it.

Answer 3

It is just a bit of drywall. It does not conduct electricity and is not combustible or flammable. Don't worry about it.