What is the powder inside wire insulation?

Was stripping some wire tonight. It was a cord that had an outside plastic/rubber sheath around 3 insulated internal wires.

When I pulled the outermost layer off a lot of white powder came with it. Anyone know what this is, and how bad it is to breath in or get on your hands?

Also while stripping the same batch of wire I was seeing red powdery dust come out of the actual braided copper wire.

Any ideas what the stuff is?



Thanks in advance

I noticed it is mostly in vacuum cleaner cords, it's like a talcum powder. I haven't had any issues as of yet as far as breathing or skin irritation.

Hi,

Careful as a computer guy once told me the white powder is mice poison should they get to the wires.
Don't know if this is true that's why I ended up in this forum in the first place to try and verify.
Cheers,
eons

I think that the white powder is french chalk, powdered soapstone?
I find it in the rubbery insulation wire mostly.

I dunno about the mouse poison, well I have at least one theory on it, one chemical they do use in insulation to stop it catching fire (fire retardant) used to be used as a mouse poison. Red phosphorous

Though I don't think you will find that poison for sale anymore.

The powder is Isocyanate and is used to stop the cores from sticking to one another simple. Now some time ago Isocyanates were classed as potential carcinogens and could cause asthma in certain people also irritating and sensitising the skin. I'm a Electrician and have been working with cables for nearly 50yrs and my skin splits around my nails and sometimes they even bleed, creams are available.
We were never told about the hazards it was only my suspicion that made me investigate further, my advice to anyone is wear disposable gloves.

The powder's a retardant in case the cord catches fire. Like with all powder, I wouldn't breathe it in.

I don't know whether it's a fire retardant or not but it's primary job is to stop the plastic cores from sticking together.
The plastic will burn like s--t all day long hence electric fires, I once saw a fire in a underground cable tunnel in the steel works and the only thing that put it out was foam so powders didn't do much that day.

Originally Posted by Jules

I don't know whether it's a fire retardant or not but it's primary job is to stop the plastic cores from sticking together.
The plastic will burn like s--t all day long hence electric fires, I once saw a fire in a underground cable tunnel in the steel works and the only thing that put it out was foam so powders didn't do much that day.

I'd say not. It was explained to me that the powder is the same type used by airports to put out fires and has a low working temp so it wouldn't stop a high heat fire. I use to find the powder in older high voltage extension cables but I guess it can be found in any length of cord.

Is the fire extingusher powder baking soda?
Being Sodium BIcarbonate, as its heated it turns to Sodium Carbonate and lets out a CO2 molecule.....?

Im not sure if this is correct, but I know that its a sure way to ruin your day/party when someone pulls out a drypowder fire extingusher and says "lets let this off, it'd be fun"
And lets it off.....