Exactly, BeO is similar to asbestos in that it causes lung tissue damage
(berylliosis - pardon for spelling) that can eventually develop into cancer.
Although not in all cases. I know a guy (a ham) who machined it for years, and
is always short of breath. Its a terrible thing. I believe that Eimac included
that little red and white note in EVERY tube box, as it was probably simpler to
do that than to try and get the proper notification into the proper tube carton
in the shipping department. If they had not warned of the hazard, they could
have been proven negligent in a lawsuit. Reading those notes, they always said
something like "this tube MAY have BeO ceramic".
There are pegmatite veins (called dikes) in the mountains near my QTH and one
mine I have visited used to have meter long beryl crystals. In mid 1940s the
miners extracted microlite, an ore of tantalum and niobium, from there. It was
used for wartime work for electronic parts and tube elements (plates, getters).
In the 1950s they extracted beryllium cyclosilicate ore. It was the leading
beryl producer in North America in 1950-51, exceeding 13,000 kg per year. In
1958 the miner working the claim died, and production ceased - over 690 tons
of 11.2% BeO and 184 tons of 5.5% had been shipped from that one mine. Four
miners dug and hauled the ore out. During the best days, they would bring about
about a ton per day by hand. A mule named Beryl lived there and stayed in the
mine for years. Needless to say, there were no dust masks or OSHA/MSHA safety
regulations then. So most of them had that disease.
A side note, Be was also used in neutron sources and neutron reflectors, and
some of the early metal came from that same mine, for the Manhattin project,
according to something I read.
Sorry to digress from amplifiers!
73
John
K5PRO, northern New Mexico
Message: 2
> Date: Sun, 18 Nov 2007 08:51:39 +0000
> From: Steve Thompson <g8gsq@eltac.co.uk>
> Subject: Re: [Amps] Misconceptions about hazmat in ham radio equip
> To: amps@contesting.com
> Message-ID: <473FFD1B.80502@eltac.co.uk>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> John Lyles wrote:
>
> > Now for beryllia. It is used in SOME power tubes, not LOTS of them. Eimac
> > had to include a disclaimer about it with every tube....
>
> I'm intrigued by 'had to' - do you know why?
>
> It is also in beryllium-copper metal used for EMI gasket material
>
> As I understand it: Be metal in BeCu is very safe. Raw Be is
> nasty, but no-one will encounter it in normal life. BeO is toxic
> in the same was as asbestos - it's not poisonous, but the
> particles cause chronic lung irritation that can develop into cancer.
>
> Steve
>
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