Corrosion

[Al D. Bolt]

I believe the white seen in the recessed area of these breakers is some kind of corrosion. Can anybody tell me more about this?

Thanks.

[chunt1]

From the pic it appears to be dust/debris...similar to what is visible on the wires and everywhere else as well. Hard to tell.

[Al D. Bolt]

Its not dust or debris. Its a white, chaulky substance in the slot across from the screw in the breaker. Its on all but one of the breakers.

[Frank P. Newman]

Based on the fact that some of the 2 pole breaker ties appear to be rusted, it is pretty clear that a corrosive environment has existed in the panel at some point. However, from the picture, it pretty hard to tell if there is any corrosion that warrants any rehabilitation.

[Jeffrey R. Pope]

It's not corrosion - I can't tell you what it is, but I believe it's something used during the manufacturing of the breaker. I see it all too often.

I'd be more concerned with the AL wiring. . .

[Marc D. Shunk]

What did it taste like?

Just kidding. I have recently learned that some of the old breakers employed a borax plug in the arc chute for arc suppression.