[AMPS] re: beryllium in tubes

Jon Ogden jono@enteract.com
Mon, 5 Oct 98 13:24:34 -0000

>>"Hi Ian - the hazard normally noted is the possibility of intense x-ray 
>>radiation when operated at full output.  The BeO is very small in
>>these tubes, normal disposal is OK in RSA!"
>I think the point here is that electrons bombarding the anode, cause
>x-ray emission as a secondary effect.
>Since I intend to operate these tubes at full output, I shall be looking
>for lead-lined boxes from now on!

Yes, you could put your tubes in lead boxes, but that would probably be 
foolish.  Few tubes give off significant X-rays at anode voltages < 10 
KV.  You need a lot of plate potential to get significant radiation.  You 
probably get far more X-ray radiation flying in a plane to your next 
DX-pedition or convention than you would from operating a linear for 
years upon years.

>The toxicity of beryllium was not queried, only a fool would belittle
>it. All of its compounds are hazardous, including salts, metals,
>liquids, and vapours. For example, literature originating in the USA (a
>government agency), gave the permissible dose for "occupationally
>exposed workers" at 0.1 micrograms/cubic meter of air/per month. I
>reckon that the average ham, pushing a guad of tubes containing the
>stuff, and passing a bunch of air through the overheated chimneys, would
>breathe in that quantity in 5 minutes!
>Note that the sypmtoms of poisoning, particularly when breathed in as
>the oxide (ceramic powder reduced to dust), could take 20 years to
>manifest themselves. There's no antidote once poisoned.

No one has ever questioned the fact about wether or not BeO is toxic.  
The question is: "In what form is it toxic?"  In solid ceramic form, it 
is not toxic.  Only in powdered form is it really toxic because unless 
you eat the ceramic there's no way for you to injest it.  BeO substrates 
do not give off dust even when air is blown over them.  BeO is in some 
ways similar to asbestos: It's harmless unless it is in particle form.  
Leave it be and it won't do anyone any harm.  

Others have pointed out that most common tubes do not have BeO in them.  
However, even if they did, how would "passing a bunch of air through the 
overheated chimneys" cause the BeO to suddenly start flaking off in 
little bits of dust?  It doesn't make sense.

I notice from your call that you aren't from the US.  US government 
publications say a lot of warnings and safety factors that aren't 
necessarily needed.  A lot is overkill to be absolutely on the safe side. 
 It's hard to understand the bull s**t that our government puts out w/o 
living here.  Lots of folks get hyper about anything that is potential 
hazardous.  Our wonderful government here mandated that asbestos be 
removed from public schools and other buildings.  Now they are finding 
out that disturbing the stuff causes worse health problems cause it 
throws all that dust into the air.  So don't believe everything you read 
from the US government (or take it with a grain of salt at least and 
apply common sense).

Lastly, if you are so concerned about your health and safety that you 
wouldn't use anything with BeO or that you would line your PA with lead, 
I'd suggest not going to the doctor's offcie, not going on airplanes, not 
driving in cars, not even crossing the street.  Life in general is 



Jon Ogden


"A life lived in fear is a life half lived."

FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm