> Hi !
> Found this link. Relevant info on hazards of Beryllium oxide.
> Seems to be more to it than long term effects ( ?? )
> Interested parties should have a look.
> http://www.inchem.org/documents/icsc/icsc/eics1325.htm
Although they say to wear all kinds of protective clothing and follow
procedures they pretty much say it'll give you a rash or might cause
difficulty in breathing. The MSDS at
http://www.brushwellman.com/EHS/MSDS/M02.pdf is much more comprehensive.
I'm not making light of the hazards or death issue, but many chemicals we
deal with both in the work place and at home that are normally considered
harmless have the same warning. The same can be said for carcinogenic, or
possible carcinogenic materials. Cleaning the bathtub and shower with a bit
of Chlorox plus tub and tile cleaner is a very dangerous situation. These
things need to be taken in context.
At one time I worked with some radioactive devices that were used to
maintain ionization levels. They were not considered hazardous in normal use
as long as they remained unbroken. They did require a license. I was
removing one from a machine when it fell into my hand in pieces. I carefully
placed the pieces on the floor and covered them with a metal pail to prevent
dispersal from air currents and to keep others away from them. The proceeded
to shed clothes headed down the hall for the shower while calling for some
one to call the HAZMAT team.
They checked me over carefully along with my clothes and commented on my
swift action. I even got my clothes back, but I will say: MAN that water was
C-O-L-D! Safety showers and eye wash stations are not a fun place to find
yourself or a place where modesty is much of a factor. The eyewash is almost
unbelieveably uncomfortable.
BeO2 is like that radioactive material in they checked around my nose, eyes,
and mouth which are the vulnerable areas of ingestion, for traces. They also
checked for any scratches on my hands, arms, face and neck which would give
access for entry for the material.
With a bit of common sense, tubes containing BeO2 can be handled safely as
can those using the thermal blocks, or coupling for cooling such as the
8873. These tubes and blocks disappeared, not because the tubes and blocks
are inherently dangerous, but because of those who might sand the blocks or
handle broken tubes without proper precautions and those whos fears brought
on greater fears of liability.
We face dangers most every day that put us at far more risk than tubes
containing BeO2 or using BeO2 thermal links such as welding or soldering
Galvanized pipe. Cleaning things with Chlorine bleach plus other cleaners
that will cause the bleach to release Chlorine. Although the limits for
BeO2 are far, far lower than these other substances we are exposed to many
many times higher levels of these. Oft times 100s or even thousands of times
higher.
Solid BeO2 is not even listed as a hazardous waste.
OTOH due to an over reaction we are being forced to remove lead from
electronics. It's not that lead isn't an environmental pollutant, but it is
necessary (so far) to prevent "tin whiskers" from forming in devices. We
need to weigh the impact of removing the lead compared to early failure of
satellites (it's already happened) to medical devices (pacemakers recalled).
It only takes a tiny amount to prevent, or greatly reduce the formation of
these "tin whiskers" and until we find a suitable replacement not using lead
may pose more of a health threat than using it.
I view the use of BeO2 the same way. We no longer have the use of a very
good material due to the improper handling of said material by a few
individuals and the fears of others.
I've had a couple amps using the conduction cooled 8873s and they were
great. I'd like to have one of the Henry's that used a pair, modified to use
three of them. Of course that would depend on being able to find the 8873s
let alone at a reasonable price. Even the little Heath was a nice amp.
http://www.rogerhalstead.com/ham_files/boat1.htm and it didn't heat the
shack like that KWS-1/75A4 did<:-)) But man, that heatsink sure did get hot.
Think of the posibilities of using water cooling on one of these heatsinks
with a bank of those little tubes on the other side. <:-))
73
Roger (K8RI)
> 73's Peter
> LA7SL
>
> ----- Original Message -----
> From: "John Lyles" <jtml@losalamos.com>
> To: <amps@contesting.com>
> Sent: Sunday, November 18, 2007 6:54 PM
> Subject: [Amps] BeO in tubes
>
>
>> 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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>>
>>
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>
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