What could this be?

[Plupp 138940]

Hello!

I'm in the process of demolition and will also be chipping away a concrete slab of 20m2. I found this white fibrous material (reminds me of fiberglass)

Does anyone know if it might contain anything dangerous, e.g., asbestos?

Grateful for quick responses

 

[Eld]

Looks like lime deposits.

 

[Plupp 138940]

Well, it's fuzzy. Long-haired. Seems to be around the sill of the slab.

 

[lob]

Well, it's vague. Hairy. Seems to be around the sill on the slab.

Glasullit, a terrible predecessor to Gullfiber. Was once up in an attic insulated with this. It was 20 years ago but it still itches.
Or it might be salt efflorescence.....

 

[Plupp 138940]

Thank you. No asbestos in this then?
3M mask and gloves might be enough?

 

[Plupp 263386]

View attachment 398996 This is what asbestos looks like.
Might be asbestos fibers. https://sv.wikipedia.org/wiki/Asbest#/

 

[lob]

[media] This is what asbestos looks like.
[image] Could be asbestos fibers. [link]

yes it was really similar. Maybe best to check it out.

 

[useless]

I have never seen pure asbestos fibers used in that way, so I also vote for an early variant of glass wool. But the only way to be sure is to send it for analysis.

 

[ArneTW]

Similar images have appeared in previous threads... and then the consensus has been some type of glass wool.

/ATW

 

[Plupp 138940]

Thank you for all the answers. I'm pretty sure they are glasullit. But I will dig soil over just to be safe.

 

[KnockOnWood]

Isn't it just a matter of trying with a candle flame?
Fiberglass melts easily, but asbestos fiber should fare better:
Melting point varies between 1150-1550°C

 

[Eld]

Isn't it just a matter of trying with a candle flame?
Fiberglass melts easily, but asbestos fibers should withstand better:
Melting point varies between 1150-1550°C

Fiberglass melts at about 700 degrees. Doubtful if a candle flame reaches that.

 

[Demmpa]

Yes, candle flames can reach up to double that,

"The flame of a candle, which is light yellow, almost white, is around 1200 ⚬C.".
chem-www4.ad.umu.se:8081/Skolkemi/Experiment/experimentfordjupning.jsp?id=157

"The temperature in the dark zone is quite low, around 600 °C, and increases to about 1200 °C in the middle of the yellow area. The highest temperature, 1400 °C, can be found in the upper outer edge of the bright yellow part of the flame."
https://www.umu.se/nyheter/nu-tandas-tusen-juleljus---ljusets-kemi_5822561/

 

[Plupp 138940]

Yes, a candle can reach up to double that,

"The flame in a candle, which is light yellow, almost white, is about 1200 ⚬C.".
chem-www4.ad.umu.se:8081/Skolkemi/Experiment/experimentfordjupning.jsp?id=157

"The temperature in the dark zone is quite low, around 600 °C, and increases to about 1200 °C in the middle of the yellow area. The highest temperature, 1400 °C, is found in the upper outer edge of the bright yellow part of the flame."
[link]

I actually tried burning just now with a small hand butane lighter, the hairs on those white ones melted instantly until they curled up into a compact ball, then they burned as long as I applied flame to them.

I also did this on a suspicious wind barrier and it completely burned up.

Is this an established asbestos test?

 

[Plupp 138940]

Found this piece today while I continued to tear around the sill. Do you think it's the end of glasullit?