So I am redoing light fixtures in my 1946 house located in the USA. I guess I'm overly scared of asbestos, and just wondering on your opinion if this household branch wire is asbestos containing.

It is hard to find images on the internet showing examples of what is and what is not. I could get this tested, but at the same time, My exposure would be very limited I think.

Would it be worth while to mist the wires with water (electricity off) to reduce dust? How do you all deal with things like this?

enter image description here

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    Don't believe the hype... It's asbestos, not plutonium. The people sick from asbestos had occupational (daily) exposure for years. All the media (endless lawyer advertisements) is because there's an established fund for victims. The lawyer demands 1/3, promising he'll "fight for you", but all he does is have an intern tick a few boxes on a form and file it. The profit margin for lawyers is ridiculous, thus the hype. Jan 1, 2019 at 20:12
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    I agree with Daniel below+ I have seen asbestos coated conductors in furnaces and ovens early in my career but never in residential wiring, the old rubber insulated cloth covered wire today usually needs a piece of shrink tubing slipped over the conductors when the insulation crumbles this brings the insulation back up to code compliance.
    – Ed Beal
    Jun 22, 2022 at 13:19

5 Answers 5


I've been in the industry for over 40 years and have never heard of asbestos in the old wiring insulation. It is oil-impregnated cloth I believe. The more pressing problems that I see from your photo are that the cloth insulation may start to crumble off the copper conductors when you manipulate the wires and that the junction box appears to be overfilled. If the conductors have been run through metal conduit then you should be able to pull new wires if necessary. If the conductors are encased in armored cable conduit aka BX then you may need to call in a real sparky. If the box is indeed overfilled then you can install an extension ring and get creative with the fabrication of a little frame around the extension ring before installing the new fixture.

  • Thanks Daniel, the picture makes it look worse then it is, there seems to be some layer of rubberish substabce under the wrapping, while it looks cracked in places, i think it is just the outer cloth jacket. Half the house was redone years back, this is the untouched half that I'm hoping to leave as is for a bit.
    – MadHatter
    Jan 1, 2019 at 22:51
  • Good answer. I'd like to add, personally, that I would have put replacing that particular junction as a priority item on 2019's to-do-list - but OP has to weigh in other priority areas at own judgement - a house from the 40s is likely to have enough issues to fit a to-do list.
    – Stian
    Jan 2, 2019 at 12:08
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    Crumbling is the problem here but it's not the cloth that is the big issue. The rubber insulation under the cloth becomes really brittle, cracks, and falls off. The key thing with this stuff is to try to avoid moving it around, especially bending and twisting. Easier said than done, I know. This is typically a problem in the box only (which isn't grounded) so wrapping the damaged conductors separately with electrical tape is basically all you can do other than replace it.
    – JimmyJames
    Jan 2, 2019 at 15:13
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    @StianYttervik It's likely that the OP has lots of stuff like this plus buried junctions and/or splices, and shared neutrals on non-obvious circuit pairs. Dealing with these as one-offs is probably not worth it. It's probably best to mitigate until the whole circuit or home can be fully rewired. Really doing it all is most efficient as the circuits from this ere tend to meander all over the place and you'll go nuts trying to figure out the path.
    – JimmyJames
    Jan 2, 2019 at 15:25

Even if there is asbestos present in that box, I'd say the hazards of messing with the wiring are far greater than the asbestos exposure, you don't develop asbestosis from the trace exposure that would be possible here. A little reading of materials readily available online may give your concerns some perspective.

The insulation on old cloth covered wiring may be deteriorating to the point it's dangerous. It's generally best not to disturb it if you don't have to, and if you have to, be prepared to potentially create a very big job rewiring.


I would doubt there to be asbestos in the 14 gauge 15 amp wires, that are in walls for outlets and light fixtures, but there is in antique cloth appliance cords for heaters, toasters, and irons. It is not much of a risk as long as you are not stripping the old appliance cord and replacing plugs or shortening it. But for both kinds of wires, stranded and solid core there is a risk of the rubber insulation below the cloth wearing out and causing an arc.


There is asbestos in the insulation of much of the older wiring. It is impossible to know if you have asbestos wiring without a microscope operated by a trained individual. Photos won’t tell you because many things look like asbestos and vice versa. Most asbestos containing home material is a combination of cellulose, synthetic fibers, and potentially asbestos- all mixed together in a single product.

As far as the hazards and consequences of exposure to asbestos (or plutonium), you have to weigh the potential risks vs the benefits and make that decision for yourself. It’s true that multiple exposures (occupational) would be more hazardous and doing a single job would invite less risk. Some people are more susceptible to the consequences of even lower exposures. It’s really up to your personal risk tolerance (and there’s the question about disposal).

I do agree that the electrical hazards are far outweigh other risks of this job pose the most immediate risk but to be cautious by minimizing asbestos exposure is not without merit.

enter image description here!

  • That's an interesting point -- I suspect asbestos-type insulations were found in early heating appliances where nowadays high-temperature silicone-fiberglass insulated wire is used? Most cloth-covered wires would not ever be exposed to temps that high in normal operation, though... Jan 9, 2022 at 8:57

There's a lawyer who has done a ton of video production stuff on asbestos. Justinian C Lane over at AsbestosClaims.law. You should check out his YouTube channel


Or any other good video on asbestos wiring, there are a billion of them.

The best thing to do is just get the home tested if you are concerned. A basic asbestos test isn't very expensive, though it does vary based on location.


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