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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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12th Jan 2009, 12:17 pm | #1 |
Hexode
Join Date: Jun 2006
Location: Bedfordshire, UK.
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PCB (Poly Chlorinated Biphenyl) hazards
Hi,
There has been mention from time to time about the dangers of coming into skin contact with PCB's that are found in some capacitors and transformers. Skin cancer and high levels of fat in the blood are a couple that spring to mind. Is it a case of a once only contact or is it like say smoking. We are constantly being told that if we smoke we could get lung cancer or heart disease amongst other illnesses , but one cigarette would be very unlikely to cause these just has one alcoholic drink wouldn't give us liver damage. I have also heard that old engine oil can be absorbed through the skin in the same way as PCB's causing similar problems. How many of the population have changed their oil in their car many times over many years with no problems ? I am not endorsing unsafe practices or an unhealthy lifestyle, I would just like your views on this. Thanks Des.
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12th Jan 2009, 12:33 pm | #2 |
Retired Dormant Member
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Re: PCB (Poly Chlorinated Biphenyl) hazards
I'm sure we've covered this before in the forum. I can't attach the document because the forum software says it's I've done it before in a closed and inaccessible thread called "nasty chemicals". Perhaps the mods could revive the thread or at least extract the document to make it visible in this thread. It's called pcbs[1].pdf
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12th Jan 2009, 12:37 pm | #3 |
Moderator
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Here's the document. I'm not going to restore the old thread, as it went way off topic.
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12th Jan 2009, 12:45 pm | #4 |
Dekatron
Join Date: Sep 2006
Location: Kilmarnock, Ayrshire, UK.
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Hi.
I'm sure as Des has said we all do things we shouldn't even unknowingly. I have come across one person effected by used engine oil though, Bob from Sorn (a telly engineer) had to get a skin graft on his hand due to Cancer. Bob has used (and still does) old diesel engine oil to coat his various sheds with. Now some of these wooden sheds have been up for 40 years so although the oil preserves the sheds its not so good on the hands. There are loads of things that are dodgy but it has to be down to common sense. I wash my hands regularly when working, I try not to inhale soldering fumes, and if I do get PCB's on my skin, I wash. Cheers Trevor
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12th Jan 2009, 7:04 pm | #5 |
Rest in Peace
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Obviously you should avoid getting it on your skin .wear thin throw away gloves perhaps . I would have thought most problems are caused by persistant contact rarther than the odd one off , but some people may be more suseptable as with people that smoke 70 years with no signs of damage and others that are damaged by passive smoke inhilation . I think common sence and not to worry too much is the best way with this .
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12th Jan 2009, 7:05 pm | #6 |
Nonode
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,820
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Hi,
that certainly made interesting reading! I shall be wearing gloves from now on when ripping appart old capacitors to re-stuff them. I have an old Philips 405 tv which has an oil filled lopt, and when I first took out the chassis to clean it I noticed the oil has leaked out a bit from the top Any chance the oil in the tv may be this PCB oil?! regards, Lloyd |
12th Jan 2009, 7:20 pm | #7 |
Moderator
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Re: PCB (Poly Chlorinated Biphenyl) hazards
You won't find many professional car mechanics not wearing latex gloves these days. It's a wise precaution to wear gloves when dealing with any potentially noxious substance. They keep the filth out of your fingernails too
Paul |
14th Jan 2009, 9:25 am | #8 | |
Dekatron
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Location: Penrith, Cumbria, UK.
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Quote:
Interestingly, when I was an electrical apprentice with British Steel a few years earlier in the 1970's, 'Pyrochlor' was being bought as the bees' knees to transformer coolant. How times changed in a few short years!
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19th Jan 2009, 2:18 pm | #9 |
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Re: PCB (Poly Chlorinated Biphenyl) hazards
The real danger is potential liver damage. Unfortunately over the years scrap yards knew nothing of the hazards and tipped such oil onto the grouind where it seeps through and eventually in maybe 50 years or more it will get into the aquifers and hence potentially into potable water. It was mainly used in large, and I mean large, transformers and capacitors which we are unlikely to come into contact with - electricity distribution stuff. However high voltage oil-filled capacitors especially Ex-WD are quite likely to have it in them. I am not aware that it was used in "waxed paper" type caps though. Disposal of the oil is an expensive problem requiring high temperature incineration followed by after treatment of the gases to remove possible dioxins.
Pat G3IKR |
19th Jan 2009, 2:30 pm | #10 |
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Further to my previous. Yes Pyrochlor and other brand names were around at that time. Like many relatively modern chemicals they were developed for a specific use for which they were ideal. They do not suffer degradation like the mineral oils previously used. They have better insulation properties. Other similar substances are the Chlorofluoro hydrocarbons used for propellants in aerosol sprays etc. These are so inert that they can be used internally for nasal sprays etc. Again they are dificult to destroy and similar procedures have to be used. Because they are so inert it was never considered that they would cause a problem in the atmosphere, which of course they don`t. It is only when they get into the stratosphere where there is sufficient high energy UV radiation that they break down and cause havoc with the ozone layer. Some of them have a 'half life' of 100 years before they finally completely break down into hydrogen chloride and are eventually washed out when they re-enter the normal atmosphere. Asbestos is another substance for which there is nothing better for some applications. And so we could go on. I spent my working life dealing with Air Pollution!
Pat G3IKR |
20th Jan 2009, 9:49 pm | #11 | |
Retired Dormant Member
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Hallo Oldtimer 74,
Quote:
for a certain time (some tenths of a second) and a slight oxygen excess. This is to avoid the formation of dioxins. Those would make a new problem even when removed from flue gas: nobody will "buy" them :=( After the inrush commotion about PCBs in the 80ties, there is much more sense here since 90ties: It stays where it is! Tenthousands of medium or big transformers still have their PCB. Moral: it does a good job where it is, and removing/transport/incineration would be a risc :=) (and expensive) Only the small capacitors were dismissed. Regards Georg |
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20th Jan 2009, 11:58 pm | #12 |
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Re: PCB (Poly Chlorinated Biphenyl) hazards
HI Georg. Yes you are right, 1000 C for 1/2 to 1 second with excess air. This means a very large device and hence cost is almost prohibitive. I am not aware of any chemical method of destruction. Could go on about these sort of problems, but I don`t think this is the forum for it.
Pat |
23rd Jan 2009, 10:41 am | #13 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
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Re: PCB (Poly Chlorinated Biphenyl) hazards
Apart from old LOPT's and the TCC 'Visconol X' capacitor are there any other components which may contain PCB which we as restorers of radios & TVs may encounter?
I nearly bought some NOS TCC Visconol X capacitors. The name rang a bell so I looked on this forum and didn't bother with the purchase. |