Why isn't anyone concerned with air quality of insulation in sound panels?

wookiegr said:

I posted this in another thread but it really needs more attention on it's own.

Does anyone have any air quality concerns with mineral wool and sound insulation in general? I'm building a theater in my basement and have installed mineral wool between all the interior studs and that stuff just rains particles like crazy. I can only imagine what it will shed into the air through the fabric as the subwoofers are pounding away. I doubt a simple cotton weave will truly save your lungs from inevitable breathing issues over time. Anyone experienced with using insulation in-room as a sound absorber want to chime in on that?

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A post from 2008:



"After several threads here on the relative safety of rockwool, fiberglass, and organic fibers, I did a few days of digging through the medical literature to satisfy my curiosity. I thought I'd share a summary of what I found, as it may be surprising, particularly regarding organic fibers.

My personal conclusion is that, from everything I read, Roxul HT rockwool appears to be the safest material available. Although traditional forms of rockwool may be harsh, Roxul HT dissolves with incredible ease in the lung and is completely noncarcinogenic in even the most intense animal tests. It's relatively gentle and has great absorption characteristics.

The types of fiberglass we use also seem quite safe and, like with rockwool and organics, have absolutely no history of causing lung cancer in people or animals from even long term exposure. Typical fiberglass like OC703 is, however, much more abrasive than Roxul HT, and thus at least more theoretically capable of inducing lung irritation issues, particularly with high-level, unprotected exposure.

Organic fibers (like cellulose, cotton, and hemp), unlike rockwool/fiberglass, do not break down in the lungs or body at all. As a result, inhaled organic fibers too big for lung defense cells to ingest but too small to cough up can be more easily permanently trapped as irritants.

Whatever you choose, always wear a mask, gloves, and protective clothing when handling any of these materials raw and you should be fine. All the materials we use should be safe for normal studio applications. Studios/manufacturers that are still concerned about using any of these materials may wish to opt for a tighter weave fabric or a layer of polyester batting or other wrap glued to the insulation underneath. In fact, that might be good advice for anyone, but that's each person's call to make.

Research below includes animal breathing and injection studies, health reviews of factory workers, and rare and unusual case studies. It isn't meant to be exhaustive or definitive. I am also not a doctor or expert and this isn't medical advice. I do have a biomed background though, so if you have any questions/comments, I can do my best to clarify.



ROCKWOOL STUDIES

Biopersistences of Man-Made Vitreous Fibers and Crocidolite Fibers in Rat Lungs Following Short-Term Exposures,
Rats were exposed 6 h/day for 5 days to massive amounts of long fiber rock/slagwool (including one fiber by Roxul), and their lungs were studied over time. After 90 days, the residual fibers found in The Rat lungs were broken down to 1/3 the maximum length macrophages (defense cells) can engulf and remove. At 9 months, retention of fibers was 1-6% compared to day 1. At 18 months, rockwool fibers were statistically undetectable. Asbestos was tested as well for comparative purposes. By contrast, it was not at all similarly digested, and at 18 months 29-47% of the original long fibers persisted.

Carcinogenicity Studies after Intraperitoneal Injection of Two Types of Stone Wool Fibres in Rats -- KAMSTRUP et al. 46 (2): 135 -- Annals of Occupational Hygiene
Rats were abdominally injected with two types of rockwool. One was a Roxul HT fiber. The other ‘typical’ traditional fiber induced cancerous growths, but the Roxul fiber had no adverse effect. These types of injection tests are important because they have higher sensitivity than breathing tests.

Chronic inhalation studies of two types of stone w...[Inhal Toxicol. 2001] - PubMed Result
Rats were hooked up to breathe the same two rockwools listed above. Exposure was 6 h/day, 5 days/wk for 2 years. Neither group developed any cancers. However, the ‘typical’ rockwool did induce some lung fibrosis/scarring. The Roxul HT did not.

Subchronic Inhalation Study of Stone Wool Fibres in Rats -- KAMSTRUP et al. 48 (2): 91 -- Annals of Occupational Hygiene
Again, a breathing test of the above two rockwools at the same dose but for 3 months only. In this case, no cancers or fibrosis were observed. Any inflammation was reversible, even with the heavy duty fiber.

The Biopersistence and Pathogenicity of Man-made Vitreous Fibres after Short- and Long-term Inhaltion -- KAMSTRUP et al. 42 (3): 191 -- Annals of Occupational Hygiene
Another two-year rockwool rat breathing test. No cancers observed. Risks with HT rockwool are deemed negligible to nonexistent.

Behavior of new type of rock wool (HT Wool) in lungs after exposure by nasal inhalation in rats
Roxul HT rockwool rat breathing study. The half-life of fibers was 34 days for all fibers and only 11 days for the longest (and thus normally most persistant and dangerous) fibers.



FIBERGLASS STUDIES

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Researchers injected rats with highly dissolvable fiberglass to assay whether or not byproducts of fiber dissolution were likely carcinogenic. No tumors were generated. They concluded that the degree of carcinogenic potency of a fiber depends primarily on the extent to which it retains its fibrous structure over time, not its chemical composition.

Pulmonary response of mice to fiberglass : cytokinetic and biochemical studies
Comparison of fibrogenic effects of fiberglass and asbestos in rats. Demonstrates that fiberglass requires doses 10x that of asbestos to induce similar levels of fibrosis (scarring) to the lung. Unknown what type/durability of fiberglass was used.

Biopersistence of synthetic vitreous fibers and am...[Toxicol Appl Pharmacol. 1998] - PubMed Result
Comparative look at fiberglass, rockwool and asbestos in hamster inhalation. The very biopersistent fibers like asbestos and specialty high durability ceramics/fiberglass were carcinogenic, while the more rapidly clearing fibers, like normal commercial fiberglass equivalent to oc703, were not at all.

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A one year fiberglass vs. asbestos breathing study in hamsters. Animals exposed to typical commercial fiberglass experienced only nonspecific pulmonary inflammation. However, exposures to a special, high durability fiberglass and asbestos were associated with lung fibrosis and possible mesotheliomas (lung cancer).

Science of the Health Effects of Fibers
OC's research paper references.


Fiberglass Case Studies

Wiley InterScience :: Session Cookies
Case study of carpenter who inhaled fiberglass unprotected for 41 years. Fibrosis, cystic lesions, and fiber deposition was noted. The authors conclude that this patient's heavy smoking history and long term exposure to fiberglass have contributed to pulmonary fibrosis. Fibers found had all broken down to short lengths, indicating the lung fluid was effective in breaking them down, but macrophages were not able to digest them. Cigarette smoking has an interactive relationship with fibers like asbestos-the asbestos worker who smokes has a much higher chance of developing lung cancer than does the non-smoker.

Clinical Pulmonary Medicine - Abstract: Volume 14(5) September 2007 p 296-301 Respiratory Disease and Fiberglass Exposure: Report of a Case and Review of the Literature.
Describes a 23 year old with an unusual adverse reaction to fiberglass. It is noted that rare cases of pulmonary fibrosis, acute eosinophilic pneumonia, and sarcoidosis-like pulmonary disease have been described after exposure to fiberglass.

Elsevier Article Locator
Studying 50 cases of sarcoidosis, an immune system disorder, 28% of patients recalled exposure to fiberglass/rockwool. Findings suggest that in susceptible people, mineral deposition from MMVF exposure may contribute to immune issues.



OCCUPATIONAL FIBERGLASS/ROCKWOOL STUDIES

ATSDR - Toxicological Profile: Synthetic Vitreous Fibers
The full version of the 2004 US Government review on synthetic vitreous fibers aka manmade vitreous fibers (MMVFs), the group to which rockwool and fiberglass belong. It summarizes all available knowledge on how the body react to these fibers and any associated risks in relatively layman friendly terms.
http://www.atsdr.cdc.gov/toxprofiles/tp161.pdf
One subsection of the above containing a referenced overview of all animal studies to date.
http://www.erj.ersjournals.com/cgi/r.../8/12/2149.pdf
A good review article of epidemiological studies following MMVF workers long term. No ill effects have been noted except minor fibrosis among ceramic fiber works. Ceramic fibers are a specialty product that is far more durable and dangerous than any form of fiberglass/rockwool. Neither rockwool nor fiberglass workers were noted to develop the same effect.

Historical cohort study of U.S. man-made vitreous ...[J Occup Environ Med. 2004] - PubMed Result
Cohort sudy of 4008 women who were MMVF factory workers between 1945 and 1978. No elevated mortality or lung cancer has been observed.



ORGANIC FIBER STUDIES

http://www.jniosh.go.jp/en/indu_hel/pdf/IH39_17.pdf
Review article regarding manmade organic fibers (MMOFs). Indicates that cellulose fibers can be more biodurable in the lung than even asbestos, which in turn is many times more biodurable than fiberglass or rockwool. Cellulose is less carcinogenic than asbestos despite this, likely because it triggers far less lung inflammation.

Tumorigenicity of cellulose fibers injected into t...[Inhal Toxicol. 2002] - PubMed Result
Researchers injected high doses of wood pulp derived cellulose fibers into the abdominal cavity of rats. Tumors were produced. They state that cellulose fibers, along with many other organic fibers, are durable. Therefore, if inhaled, they have the potential to persist within the lung, and may cause disease.


Organic Case Studies

Diffuse lung disease caused by cotton fibre inhalation but distinct from byssinosis -- Kobayashi et al. 59 (12): 1095 -- Thorax
Case study describing a 66 year old man who had inhaled cotton fiber for 50 years at his workplace. His lungs demonstrated callusing of their lining and diffuse fibrosis. Strings of cellulose fibers were found in his lungs. According to the researchers, this was the first study to show directly that cotton fiber inhalation can directly cause diffuse lung disease unrelated to byssinosis.
MedlinePlus Medical Encyclopedia: Byssinosis
Byssinosis is an occupational lung disease in textile mill workers exposed to the respirable dusts of cotton, hemp, and flax. It is characterized by a chronic, asthma-like narrowing of the airways and caused by the bacteria which grow on the fibers."