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General Science => General Science => Topic started by: hlbkv on 23/04/2019 00:14:55

Title: What kind of hazardous residue results from a small house fire?
Post by: hlbkv on 23/04/2019 00:14:55
So a few days ago one power wall socket caught fire in my bedroom, and may have burned for about 10 mins before I noticed the smell (door was ajar, window was slightly opened) and proceeded to drown it with a cup of water (the socket had already fallen to the floor and was burning brightly on the hardwood floor), being careful enough to hold my breath while inside the bedroom to avoid directly inhaling the fumes. I opened all the windows in the apartment and went for a 10 min walk outside while the air cleared. I then have spent about an hour removing stuff from the bedroom, careful to hold by breath and only inhale in the balcony or on the WC (where the smell was mostly not present).

Later I was reading on the danger and toxicity of fumes released by burning plastic, which is probably futile after the fire (a charred dark blob was all that remained), but from what I was able to gather it's unlikely that it was PVC (particularly worrisome due to dioxin and furan release). The smell was not at all sweet and quite unpleasant, the smoke was black and filled the bedroom (along with some other corners of the house) with black soot, which is characteristic of ABS or epoxy plastics. Furthermore, PVC is mostly used for wiring, insulation and outdoor applications, and rarely (if ever) for wall socket outlets.

Still, dangerous (toxic and possibly carcinogenic) volatile compounds were released, and particularly due to the black soot it spread throughout the house, I was wondering what kind of residue from those substances would remain. Do they mix/dissolve/associate with fabrics and furniture? Is heavy-duty washing required or just removing the sooth with a napkin enough (as they would be re-solidified plastic)? What kind of health risks are associated with the exposure to that soot, or with fabrics that may have been in contact with the fumes?
Title: Re: What kind of hazardous residue results from a small house fire?
Post by: evan_au on 23/04/2019 11:13:50
Quote from: OP
caught fire in my bedroom, and may have burned for about 10 mins before I noticed the smell
Ideally, these fumes would have set off a fire alarm.

If you had been asleep in the room with the windows closed, you may not have woken up at all...

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proceeded to drown (the power socket) with a cup of water
This is the next most potentially lethal part of the encounter. If the power socket were still "alive" when you poured on the water, you may no longer be "alive".

Perhaps it was an insulating cup, or the power had already cut off, or you have very pure water!

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the danger and toxicity of fumes released by burning plastic
But you did the right thing by opening the windows and going outside (once there was no further danger of fire).

In terms of lifetime health risk, this short exposure is negligible.
There may be some residual smell, but since it is outside your body, this presents an annoyance, not a direct health risk.
- Wipe down hard surfaces
- You could hang rugs and pillows outside, and perhaps beat them to free up any loose particles.
- A vacuum cleaner will probably extract more particles; some larger particles might be caught in the filter, but most small particles would go straight through the filter, so use the vacuum cleaner outside.
Title: Re: What kind of hazardous residue results from a small house fire?
Post by: hlbkv on 23/04/2019 15:42:59
Ideally, these fumes would have set off a fire alarm.

I do not have a fire alarm, nor was I on the bedroom. The bedroom window as also slightly open, which also provided some minimal ventilation. I may also have misjudged the situation when I initially felt the burnt plastic smell, which started before any kind of fire, and though it was being caused by a wall lamp next to the outlet (which I promptly turned off).

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This is the next most potentially lethal part of the encounter. If the power socket were still "alive" when you poured on the water, you may no longer be "alive".

The socket had already fallen to the floor, and there was no wiring connecting it to the wall (there was no electrical appliance plugged into it). It was impossible for it to be live. And I splash it from afar, was careful to keep my distance.

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But you did the right thing by opening the windows and going outside (once there was no further danger of fire)

Only for 10/15 mins though. The smoke was mostly gone, but the smell was quite intense still. I then spent about 45 min to an hour going in and out of the bedroom removing clothing I had lying on the bed, as I worried the smoke might have damaged it. I only "saved" clothing that had did not smell, had no soot at all or soot that I could beat/blow away without smearing, anything else was marked for deep cleaning or sent straight to the trash.

Luckily, I had a flight scheduled for the next morning which allowed me to avoid sleeping on the bedroom altogether and leaving the apartment to ventilate for a few days, but on the other hand I was unable to wash the clothing I had "saved".

What worries me at this point however (even though I was careful to hold my breath when in the bedroom, I may still have inhaled dangerous stuff) is 1) the time I spent going in and out of the room and exposed my skin to those fumes and residue; 2) if the fabrics have somehow assimilated those volatile compounds and any contact with them is now somewhat dangerous (or at least until I clean/wash them); 3) and potential contact with overlooked soot residue on the clothes that I may have overlooked.

Title: Re: What kind of hazardous residue results from a small house fire?
Post by: evan_au on 24/04/2019 00:44:12
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exposed my skin to those fumes
The good news is that the outer layer of your skin cells are dead!

That means that even if some residual chemicals/larger particles are slightly toxic, or even cancer-causing, it can't damage your skin, since it is already dead.

The initial volatile gases and tiny particles make their way down into your lungs, which consists of living cells.

But a short exposure (minutes) is not a problem - after all, some humans have had smoky wood fires in their houses or coal fires in their towns for decades: that is a serious exposure that would have a measurable impact on lifespan.

See: https://en.wikipedia.org/wiki/Epidermis#Cell_division