Beryllium Oxide Question

[JohnG]

Beryllia (beryllium oxide) is a hard, brittle ceramic with high thermal conductivity (it almost feels like a piece of metal when you handle it). It is not so toxic in solid form, but any dust formed by machining beryllia is highly toxic.

It is unlikely that any flexible insulator contains beryllia due to the hazards of handling it in fine particle form. As mentioned previously, boron nitride is the usual filler in high performance thermally conductive flexible insulators, although alumina (aluminum oxide) is sometimes used. These types of insulators can work very well.

Beryllia is sometimes contained in power semiconductor packages, and these are usually clearly labeled with at least "BeO" to warn the user not to drill, machine, or perform any other operations that may result in dust.

A little story about beryllia:

When I was in graduate school, a student (in another building/department) successfully sued the school when it was discovered that an improperly installed ventilation hood was venting beryllia dust into his lab. By the time this was discovered, he was pretty much stuck spending the rest of his life in a wheelchair due to mostly diminished lung capacity. All the money in the world won't get his breath back. He probably got a lot higher dosage than most, but be warned.

John

[Stabist]

I bring this old topic back to life - so there is no possibility that white, thin, flexible insulator would be containing berillium ...

I mean - more than a year ago I got some smaller power supplies from big IBM's CPU unit ... And ofcourse I've dissassembled them - there were also white, thin shets of some insulating material - that have some fibers and some dust when cutted ... I guess that's just normal silicone or some kind of similar insulator ...