Asbest in systems!

Dear Member

Normally asbest is plate insulator between Hot tube or resistor and inflammable material like wood. Asbest is REALLY PERILOUS. One partickle in lung can be cause tumour. So take asbest carefully away protected yourself suffcient without inhale.

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Unluckly asbestos used as thermal insulator was very common in several small ac/dc American sets, but also in a some Italian ones (both pre-war and after war).
I'd like to ask a question to other collector: how do you behave to asbestos?
I usually remove it in open space (with some wet fabric as mask :), but I wonder if it could be safer to inoculate it with some paint.

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Dear radio friends
there is a risk when working on isolations containing asbestos fibres in historical radio sets.
Asbestos has been used widely, for electrical isolations, in electrical heaters, hairdryers and toasters, in the brake pads and clutch plates of cars. In houses asbestos boards and mats have been used for fire protection, in buildings and railway wagons as asbestos foam / "flocked" asbestos.
The main risk is caused by asbestos fibres / dust penetrating in the lower airways / lungs and causing lung or pleural cancer (so-called mesothelioma) sometimes many years after inhalation.

So we should prevent inhalation of asbestos fibre containing dust. By simply removing isolations made of plates with bound asbestos, there should only be a minor risk.
The asbestos material should be stored in a plastic bag and brought to a special disposal company.
There is a high risk when drilling holes, cutting, milling or grinding / polishing asbestos containing materials. I would rather taking them out of the set then trying to make an asbestos plate fitting in a set.
For such work, I would wear rubber gloves, a breathing mask classed P2 S or P3 (designations we use in Switzerland) and maybe an old work coat that can be discarded after use.
If You have access, use a vacuum suction pump to get the dust away when drilling or milling, or at least work outside on a windy day...

Things I would absolutely not touch are isolations made of "flocked asbestos" as found in old railway wagons around electrical installations. This foamy isolation material gives very much fibres / dust when You work with it, leave the discarding of these materials to specialists with optimal protection clothes.

There are many informations found on the governmental internet sites, in Switzerland
at the site of the national insurance SUVA (http://www.suva.ch/home/suvapro/branchenfachthemen/asbest_neu.htm?WT.svl=sub)
or at http://www.forum-asbest.ch (sorry, only in German, French and Italian.., but look for Your National Environmental Medicine website using google...).
Greetings from Switzerland
Martin

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I'm afraid that we could get indeed problems with toxically and dangerous substances. But I am no expert , and it is not quite clear for me what you are meaning with "small American AC/DC sets before and after WW II" . It could be useful for all of us to create a list of dangerous substances and where they are to find, e. g. dioxine in old high voltage capacitors (only an example, I am not sure about that) and the solution how to treat and to get rid of them in a legal way. What is the opinion of the other members?

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We all know how dangerous asbestos can be but in old radios it gets even worse because it is usually partially or totally deteriorated and falling apart.

I prefer NOT to remove it because when doing so, we create a waste problem. Removal can also be dangerous if done improperly. The safest way to deal with it in my opinion is to cover and SEAL it completely with a layer of kitchen aluminum foil and staple it all around (if its a wooden cabinet) You can use a sharpie or stick a label warning future owners about the asbestos. This method has the added advantage of allowing the asbestos to continue to perform its function, which is to isolate the cabinet from the extreme heat generated by the rectifier/audio output tubes.

Since asbestos is usually inside the cabinet, this method is not affected by refinishing (unless of course you decide to refinish the inside of the radio).

Asbestos is dangerous when particles are airborne, so I have heard of other collectors and restorers who "paint" the asbestos with varnish or lacquer, thus making it impossible for particles to "fly". I have not tried this method, so I can´t tell whether it´s good or bad but the most important thing to keep in mind is not to breath it.

Keep it safe, keep it fun!

Mario

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A list of dangerous substances in radios might be quite useful to the radio community as a whole.  I worked on radios for many years before learning that the yellow powder that forms on cadmium plated chassis is hazardous.  Sometimes I wonder just how careless I was with it, and to what extent I may have inhaled the dust.

I hear that the main hazard with asbestos is brushing it or otherwise abrading it in a way that stirs up small asbestos fibers into the air where it can be breathed.  For those unfamiliar with asbestos, this is easy to do -- particularly when brushing or vacuuming dust out of a radio cabinet.  If you simply leave it alone, the danger is greatly reduced.

Are there other hazardous substances that are routinely encountered?  I have seen PCB mentioned recently, and dioxin in this thread.  Are they commonly found?

Everyone has different risk assessments of the dangers of these various materials.  Even those that don't think these materials are particularly dangerous would probably still appreciate knowing what materials are present and what hazards some people attribute to them.

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Dear Thomas,
there already is a separate thread on the PCB issue :
http://www.radiomuseum.org/forum/pcb_in_kondensatoren_eine_gefahr_fuer_ihre_gesundheit.
html
(Sorry, I cannot place a link here because the editor does not 'like' Mozilla users - nor is it possible to use HTML code on rm.org. So you need to copy it into 'Location' in your browser and hit 'Enter')
The thread mentioned above is a thread written in German. If you need an excerpt in English, let us know.

However, when it comes to radios 'Made in Germany', there are just a few containing PCBs. Only those having motor driven dials and/or volume pots may sometimes use one or two motor caps filled with PCBs.
And I cannot remember any U.S. made radio containing PCBs, but I didn't take a close look inside too many of these so far - a few hundred only.
Some tape recorders have PCB caps built in - especially AEG-Telefunken.
A small minority of tube era TV sets does use a capacitor as an energy saving series resistance for the tube heaters. Those may sometimes be caps of the 'nasty' kind, too.

Most important point : Electrolytic caps do not contain PCBs. Only caps made to withstand line or higher ac voltages may sometimes contain PCBs - i.e. Power factor or motor capacitors. Within European Union, it is not allowed any more to manufacture (or import, etc.) any cap containing PCBs since Jan 01,1983.
Keep away from AC caps 'Made in GDR' (Eastern Germany) or USSR ! These are most likely to contain PCBs until 1990 (GDR). USSR until ?? I don't know.
Any MP - capacitor (invented and introduced by Bosch/Siemens in the early '40s) will be FREE from PCBs. You'll find lots of these in some vintage lab / test & measurement gear made by Rohde&Schwarz and others.
The MK- type cap does not contain PCBs, too. But MPs and MKs do contain mineral or other oils.
Best regards,
Burkhard

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Asbestos is found also in some of the line cords of old American radio's. For those who have not come across line cord it is the mains supply cable which consists of a normal conductor and a resistance wire insulated with asbestos, used to drop the mains voltage. Quite often the asbestos was also in the form of a washer holding large power resistors in place.

The other very toxic substance is Beryllium Oxide (BeO) used as an insulator under power transistors. It is in its most dangerious powder form in some RF power transistors. It should not be machined in any way. Each insulator should be in its own bag to prevent powder forming through rubbing. Beryllium is used in steel washers and springs and in this form is safe as far as I know

The other dangerious items are the coatings on the inside face of cathode ray tubes (CRT).

Alist would be a good idea and also the symbols used to denote the item such as the scull and cross bones for BeO.

I am not an expert on these maters.

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