Lab said its not asbestos, but.....

[HardDrive]

I took a sample of some insulation that I was 99% sure was asbestos to a lab(place has good reputation) for testing. Well it came back negative. To be frank, I'm not sure I trust the result. Should I retest at different lab using sample from different place?

Did Johns-Manville make any insulation products that did not contain asbestos? House was build in 1947. Material appears to be loose balls poured between the ceiling joists, its held in place with paper on vertical surfaces. I'm going to isolate it with plastic regardless. This is up in the attic, and there is no air flow into the home.

What do you say?

[Mothy]

Where I live (Australia) Rock Wool is not Asbestos but is made from the 'Slag' which is a byproduct from steel making in a blast furness.

The Steel mills used to just dump the stuff until they discovered it could be turned into insulation.

Tim

[Hugh R]

mansville hasn't made asbestos containing insulation in decades. It says "Rock Wool" it's cellulose. I used to be in the asbestos abatement business and still get involved from time-to-time.

[Dueller]

What does the research show about the health and safety of rock and slag wool?
The health aspects and safe use of mineral wools have been examined for nearly 70 years. NAIMA and its member companies have invested tens of millions of dollars in research projects - with leading independent laboratories and universities in the United States and abroad - to investigate the possible human health effects of rock and slag wool as well as other synthetic vitreous fibers (SVFs), such as fiber glass.

Industry studies, as well as studies by governments and others, have examined the following:


Airborne levels of rock and slag wool fibers during their manufacture, installation and use;


The health of more than 13,000 current and former workers engaged in the manufacture of rock and slag wool in the United States and Europe; and


The effects of rock and slag wool on laboratory animals.


Findings from all types of studies have been consistent. Airborne levels of respirable rock and slag wool fibers have been demonstrated to be very low, less than one fiber per cubic centimeter of air (1 f/cc) in most instances. Studies among workers have demonstrated no consistent association between lung cancer or non-malignant respiratory disease and occupational exposure to rock and slag wool.

For more details on recent scientific studies on the health aspects of rock and slag wool insulation, visit the Research section of this site or visit the NAIMA Literature Library for a complete listing of health and safety literature.

^ top

Do rock or slag wools cause cancer in people?
Studies examining possible health effects and safe use of mineral wools have found no consistent association between exposure to rock and slag wool and respiratory disease or cancer in humans. The weight of the scientific evidence confirms that rock and slag wool are safe to manufacture, install and use when manufacturers' recommended work practices are followed.

In October 2001, an international expert review by the International Agency for Research on Cancer (IARC) re-evaluated the 1988 IARC assessment of glass fibers and removed glass, rock and slag wool fibers from its list of substances "possibly carcinogenic to humans." All fiber glass and rock and slag wools that are commonly used for thermal and acoustical insulation are now considered not classifiable as to carcinogenicity to humans (Group 3). IARC noted specifically: "Epidemilogic studies published during the 15 years since the previous IARC Monographs review of these fibers in 1988 provide no evidence of increased risks of lung cancer or mesothelioma (cancer of the lining of the body cavities) from occupational exposures during manufacture of these materials, and inadequate evidence overall of any cancer risk." The IARC downgrade is consistent with the conclusion reached by the U.S. National Academy of Sciences, which in 2000 found “no significant association between fiber exposure and lung cancer or nonmalignant respiratory disease in the MVF [man-made vitreous fiber] manufacturing environment.”


^ top

Do rock and slag wool fibers contribute to problems with indoor air quality?
Rock and Slag wool fibers actually improve the indoor environment by controlling heat loss or gain while reducing condensation and also providing acoustical insulation. Once rock or slag wool products are installed, no significant fiber release occurs.

The majority of airborne fiber levels in buildings containing one or more rock and/or slag wool products are very low, generally less than 0.001 f/cc. In fact, in 1990 the World Health Organization's Working Group on Indoor Air Quality reviewed all scientific studies and concluded: "Current airborne man-made mineral fiber concentrations in indoor environments are considered to represent an insignificant risk."

[masraum]

I found this online

Rockwool has been made in my town in Minnesota for many years. The US Gypsum company owned the facility for many years and now it has a new owner. For all practical purposes it is fiberglass. It is made by melting a special rock and sending a blast of steam thru it.

If it's rock wool, it is neither asbestos nor vermiculite. Try some Google searches on rock wool (name used more in UK, Australia and New Zealand) or mineral wool (N American term). The stuff is no more dangerous than fiberglass to work with.

[Hugh R]

After thought, while not asbestos, it can still cause respiratory problems, and skin problems. The manufacturers, treat it like asbestos for the health of their workers. Wear an N95 dust mask, gloves long sleeves and long pants when handling to any great extent.

[dad911]

If you lay plastic over it, you are adding a second vapor barrier. Vapor barrier is supposed to be on the 'conditioned space' side of the insulation, not over it.

You do not want to trap moisture in the insulation.

[Mike Bonkalski]

That looks a lot like mineral wool.

I used to analyze samples (AIHA Accredited Lab) many years ago and still have access to a Polarized Light Microscope, so if you want me to take a look send me a PM.

[red-beard]

http://en.wikipedia.org/wiki/Mineral_wool

My house in Mass (1840 farm house) was full of that stuff. My next door neighbor's house was insulated with...newspaper

[porsche4life]

We have blown in rock wool and it sucks when you have to do something in the attic. Need a dust mask and full cover in the middle of summer. Yuck...

[masraum]

Originally Posted by red-beard

My next door neighbor's house was insulated with...newspaper

That would be an interesting find. I'd love to live in a really old house. I suspect it would be really interesting. I also suspect that it could be a real pain in the arse when stuff needs to be repaired. I see lots of custom work and time to do stuff that would be easy in a newer house.

[Dantilla]

Whatever it is, the best thing to do is leave it alone. As long as it's not disturbed, it can cause no problems. Using it as a suger substitute is to be discouraged.

[onewhippedpuppy]

I would set fire to your house, just to be certain. That's almost as scary as R-12.

[red-beard]

Originally Posted by masraum

That would be an interesting find. I'd love to live in a really old house. I suspect it would be really interesting. I also suspect that it could be a real pain in the arse when stuff needs to be repaired. I see lots of custom work and time to do stuff that would be easy in a newer house.

When I was doing some renovating work, I found a cigarette pack (empty) above the ceiling. It helped me date the work to prior to WWII. Lucky Strikes, in a green package. During the war, they stopped using green, supposedly for the war effort, and kept the package white after the war.

The ceiling had a fiberboard (basically cardboard) nailed to the floor joists. The seems were covered with a thin strips of wood, which then were made into a square pattern. We pulled it down, stained the rough cut floor joists and bottom of the rough 2nd floor floor boards (18-24" wide plank pine!). My ex-wife had lots of antiques, and this fit well with the theme of the house.

[Syntax]

Hey were you able to figure it out?