Does rock wool contain asbestos?

[Jim Morrison]

One lab tells me: "almost always", another says "almost never".

What is your experience?

[Jim Morrison]

George,

I've thought it contained asbestos for so long, I can't remember where I first heard it. Now a very good client of mine wants to know and I told him I'd ask around.

[hausdok]

Hi Jim,

With the noise that the Seattle PI has been making around these parts over vermiculite insulation and other asbestos-containing products, I'd be hard-pressed to believe that mineral wool contains asbestos, 'cuz they've never said that it does and attics insulated with mineral wool here probably outnumber fiberglass and cellulose combined by 2 to 1.

ONE TEAM - ONE FIGHT!!!

Mike

[kurt]

Just to make it confusing, I tested some rock/mineral wood about 18 years ago & found asbestos. Based on that finding, I then recommended testing on the next (approx.) 500 houses I found that had rock wool. None of the material tested was ACM.

I know that it (rock wool) can be ACM, but I think the percentages are pretty small.

[Bill Kibbel]

Rock wool is made from slag, waste from the production of iron and steel and some traces of mining waste. Although I've heard it too, I've never seen any documentation that it contains asbestos. In the late 40's, a spray-on insulation composed of asbestos and rock wool was developed to protect the steel structure of office towers from failing in a fire.

In my area, some homes near a ship building yard had some loose insulation that could be mistaken for rock wool. This white, wooly material had very high asbestos fiber counts. Workers at the ship yard would take this stuff home and fill their attics with it. Naval ships were loaded with it.

[Brian G]

Interesting. Does anyone have a good picture of the stuff?

Brian G.

[Les]

It has been my experience that rock wool and mineral wool are different products. Various types of mineral wool contain asbestos. Rock wool was a "clean" trade line and looks slightly different. A consistent color. Matter of fact looks just like white asbestos that was used for steel protection. Problem is we all call the stuff rockwool. I don't call it, cuz it is iffy. Kinda like - I WILL FIND MOLD in your house. Look in Barnes and Noble for healthy house books, most of them have really good pictures.