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Health Aspects

Eurima has always viewed the safety of its member's products as being of the utmost importance; not only for the general public but also for those working with them. Following intensive research mineral wool products fulfil the EU criteria for non-carcinogenity by a wide margin.
To ensure the highest standards, Eurima has adopted the International Labour Organisation's Code of Practice into its own.
A report which details research into the health aspects of mineral wool can be found below (link at end of section). A review of the scientific evidence from national and regulatory bodies concludes ".insulation wool products pose minimal, if any, risk to humans".

International Agency for Research on Cancer

The International Agency for Research on Cancer (IARC) - part of the World Health Organisation - in October 2001 concluded that mineral wool insulation was ". unclassifiable as to its carcinogenicity to humans".

Link to the IARC
http://www.iarc.fr/ENG/Press_Releases/archives/pr137a.html

EU Directive 97/69/EEC

This Directive provides a means to demonstrate lack of carcinogenic potential and mineral wool meets or exceeds these requirements so is not classified as a carcinogen in EU.

Code of Practice

The International Labour Office (ILO, part of the UN) Code of Practice sets out the safety requirements and precautions for mineral wool installation for all parties concerned, from manufacturers, suppliers through to competent authorities. The ILO Code of Practice is available at:

http://www.ilo.org/public/english/standards/relm/gb/docs/gb277/pdf/stm-6a2.pdf

Report on Health Aspects of Mineral Wool

Insulation Wool

(Glass Wool, Stone Wool, Slag Wool)

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Table of Content:

1. INTRODUCTION

Insulation wools belong to the generic group of man-made vitreous fibres (MMVF) also known as man-made mineral fibres (MMMF) or synthetic mineral fibres (SMF). The insulation wools are significantly different from other types of MMVF such as refractory ceramic fibres, reinforcement fibres and glass microfibres for special applications. Insulation Wools are different not only in the dimensions of their fibres but also in their chemical composition and their biopersistence. Specifically, insulation wools are defined within the European Union as being man-made vitreous (silicate) fibres with random orientation and with the Na2O+K2O+CaO+MgO+BaO content exceeding 18% by weight.

Insulation wools dissolve more readily in physiological fluids in the lung than most other MMVF and thus do not persist in the lung. They have a low biopersistence.

The lack of inhalation risk is in contrast to the known effects on the lung and pleura of more durable fibres.

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2. USES OF INSULATION WOOL

Insulation wools have been widely used for more than 60 years, in thermal and acoustic insulation and fire protection. Their most important applications are as insulation for buildings, pipes, boilers, ventilation ducts, vehicles, ships, appliances and growth media. Insulation wools make a significant contribution to energy-saving and thus to the protection of the environment.

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3. CHARACTERISTICS OF INSULATION WOOL

Insulation wool products do not burn, rot or absorb moisture or odours. Their use in buildings started in 1904 or earlier. Large scale production began in the 1930s. Investigations have shown that even old products (with the exception of those manufactured from coarse fibres) present a similar fibre diameter size spectrum as those of today.

Dimensionally stable products with binders based on synthetic resins with added dust suppressant agents were developed in the 1940s. The curing process by hot air drying hardens the resins and removes volatile substances from the product.

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4. RESPIRABLE DUST

In the manufacturing and processing of insulation wool products dust can be produced, especially when fibres break through mechanical stress (cutting, sawing, milling, crushing or pressing). Most of the particles produced in this way are too coarse to be respirable or do not have a fibrous consistency.

Some airborne fibres are respirable (defined as having diameter <3µm and length <200µm). The concentration of airborne fibres in the manufacturing plants is well below 1 fibre/ml. Exposure levels during the installation of insulation wool are mostly comparable to those in the manufacturing process. The reason for the very low airborne fibre concentration figures is that almost all products are made with a dust suppressing oil and with a binder which together control dust release from the products. Higher concentrations of dust may occur only in special applications such as the installation of blown or sprayed wools or the handling of old material in confined spaces with limited ventilation. Appropriate face masks should be worn for these applications. Insulation wool is generally installed in such a way that no further release of dust occurs after application. Air samples have been taken for fibre content in a number of buildings in which insulation wool products have been previously installed. Evaluations to determine possible exposure of occupants have shown no significant generation of airborne fibres.

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5. HEALTH RISKS FROM RESPIRABLE FIBRES

In 1972, the first evidence suggesting that MMVF may be a hazard to man was published . In response, Eurima created the Joint European Medical Research Board, an English registered charity, to advise Eurima on research priorities and to initiate and sponsor relevant research into possible adverse health effects of MMVF. The members of JEMRB are independent scientists.

Eurima and other trade associations, particularly in the USA, together with member companies have sponsored much of the independent research conducted into the health effects of MMVF. The total sponsorship by the production industry has exceeded 40 million EUROs.

There are three main areas of research:

epidemiological studies look for unusual or unexpected patterns of diseases or symptoms in humans and relate these patterns to levels of exposure to airborne fibres and to known hazards such as cigarette smoking; to correlate the findings of epidemiological studies with the hazard imposed by the exposure to airborne fibers, influences by the confounding factors are evaluated and may be further disregarded in the analysis.
animal experiments use controlled high levels of exposure to fibres and assess the animals' responses;
solubility in body fluids and other characteristics of the fibres are studied to determine and control potential risk factors.

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5.1 Epidemiological Studies: Mortality

In the large epidemiological studies of workers from the insulation wool production industry in Europe and North America no causal relation has been established between exposure to insulation wool fibres and malignant lung diseases (lung cancer or mesothelioma) . Mesothelioma are malignant tumours of the pleura or the abdominal cavity, characteristic of exposure to asbestos decades earlier.

The epidemiological studies now involve more than 60,000 production workers in Europe and North America many of these having been first employed in insulation wool production more than 40 years ago. There is no evidence in the epidemiological studies that mesothelioma are associated with exposure to insulation wool. For lung cancer the overall evaluation gives the following picture:

Glass wool: The latest follow-up to 1990 of the European study found "some excess of lung cancer" but the excess was "clearly reduced once local adjustment factors are applied to national [comparison] mortality rates" and the excess had "no relation with duration of employment nor time since first employment".

The latest follow-up to 1989 of the US study has not yet been published but the previous follow-up reported a small, but statistically significant increase in lung cancer. The authors concluded that although the overall mortality from respiratory cancer is elevated in the total cohort there was no association between this excess and any index of exposure to fibres.

Stone/slag wool: There was also some excess of lung cancer in the stone/slag wool sector according to the latest follow-up to 1990 of the European cohort. However, much of the excess was observed in one European production plant where workers had been exposed to various confounding factors. Several workers had received compensation for occupational diseases caused by these exposures. For the remaining plants there was very little evidence of an association between stone /slag wool production and any excess of lung cancer.

To establish the reasons for this unexplained excess in the stone/slag wool sector, Eurima has provided funding towards a lung cancer case-control study being conducted by IARC (International Agency for Research on Cancer).

The latest US follow-up to 1989 has been published for the stone/slag wool sector . They concluded that there was no evidence of any relation between exposure to fibres and lung cancer risk. A case-control study showed that the greatest risk was from cigarette smoking - as expected - and that that there was no association between lung cancer risk and fibre exposure. As regards non-malignant lung disease (e.g. fibrosis) in spite of intensive studies no significant excess has been found.

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5.2 Epidemiological Studies: Morbidity

Many studies of the health of insulation wool workers have been carried out during the last 30 years. The most comprehensive studies, covering some thousands of workers, have found no evidence of any adverse effects on respiratory health of exposure to insulation wool fibres. Hughes et al reported in 1993 that after ten years of study of producers in five American plants, "we have failed to demonstrate any adverse effect of MMMF exposure on respiratory health. We have found the workers to be generally healthy, without any detectable evidence of occupationally-induced respiratory disease". In an Australian study of workers in eight production plants, Brown et al (1996) reported "We found no evidence of pulmonary fibrosis, occupational asthma, lung cancer or occupational pleural disease" .

Two small studies have looked at respiratory effects among end-users of insulation wool and reported some evidence of adverse health status. However, one of these studies has been repeated without such findings; both were limited by absence of exposure data, failure to use appropriate control groups or by the existence of other possible causal exposures.

The morbidity studies were recently reviewed with the conclusions that "there is no persuasive evidence that glass, rock or slag wool exposure is a risk factor in chronic airways obstruction" and "MMVF exposure has not been shown to result in radiographic (or other) evidence of a diffuse pulmonary process (pneumoconiosis)".

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5.3 Animal Studies

Most international scientists and organisations such as the Environmental Protection Agency (EPA) in the USA , and the International Programme on Chemical Safety (IPCS) believe that inhalation tests are the most relevant for assessing possible risk to man.

No inhalation experiment involving insulation wool has ever produced a single mesothelioma nor any statistically significant evidence of an excess of lung tumours compared with their unexposed or clean-air controls. These statistical assessments were carried out using the criteria of the US National Toxicology Program .

Rat inhalation experiments , using state-of-the-art techniques at the Research and Consulting Company, Switzerland (RCC), did produce evidence of a fibrotic effect of a stone wool fibre in rats at the higher exposure levels (at least 500 times higher than the level to which production workers are maximally exposed). The fibrosis occurred late in the study and was at a low level. In contrast, the animals exposed to more durable fibres showed marked fibrosis within three months of the start of exposure.

These results are important and consistent with the particular characteristics of insulation wool fibres. The studies showed that insulation wool fibres have a low biopersistence and so do not survive in the lung long enough to cause disease.

Only in animal experiments in which insulation wool fibres were applied by injection or implantation into the pleural or peritoneal body cavities could excess tumours be produced. Many experts believe that these tests are only suitable for screening and are not adequate alone for risk assessment. Such experiments by-pass the normal defence mechanisms in the lung such as phagocytosis and fibre dissolution.

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5.4 Biopersistence Studies

The relevance of solubility and biopersistence information to the potential health risks of any fibre forms a background theme to this Eurima Fact Sheet. Much of this research is sponsored directly by Eurima member companies.

In the biopersistence studies, animals are exposed to man-made vitreous fibres by short-term inhalation (usually 5 days) or by intra-tracheal instillation. The clearance of the fibres from the animal lungs is monitored for up to one year. The EU exoneration criteria (see section 6.1) concentrate on the clearance of fibres longer than 20 µm, as they are too long to be cleared by alveolar macrophages. The results show that for much current insulation wool production, the clearance of long fibres is faster than the clearance of inert particles, and much faster than the clearance of long asbestos fibres .

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6. EVALUATION OF HAZARD TO WORKERS AND USERS OF INSULATION WOOLS

Hazard identification is only the first step in the total process of management of risk to humans from exposure to dangerous substances or circumstances. Hazard identification takes no account of the degree or extent of exposure. A dangerous substance - with no exposure - causes no risk. A positive hazard classification does not quantify strength of effect or potency nor does it quantify possible occupational risk.

The legally binding hazard identification in Europe went into force after several years of deliberation when the European Union published in December 1997 the classification of man made (vitreous) silicate fibres under the 23rd Technical adaptation of the Directive 67/548/EEC .

For carcinogenicity, insulation wool fibres (defined as in section 1 above) have been classified as category 3 "possibly carcinogenic" but with non-classification criteria. Nota Q of the Directive 97/69/EC states "The classification as a carcinogen need not apply if it can be shown that the substance fulfils one of the following conditions:

a short-term biopersistence test by inhalation has shown that the fibres longer than 20 µm have a weighted half life less than 10 days or
a short-term biopersistence test by intratracheal instillation has shown that the fibres longer than 20 µm have a weighted half life less than 40 days or
an appropriate intra-peritoneal test has shown no evidence of excess carcinogenicity or
absence of relevant pathogenicity or neoplastic changes in a suitable long term inhalation test."

Insulation wools contain a proportion of thicker fibres, which may itch the skin and cause reversible temporary symptoms due to the mechanical action of coarse fibres as may occur with any non-fibrous dust. To cover this effect, the EU chose to classify all insulation wools as "irritant to the skin".

In addition, the European Union will review this Nota Q after a period of five years during which further evaluation of scientific developments shall have taken.

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7. EVALUATION OF RISK TO WORKERS AND USERS OF INSULATION WOOLS

Several expert groups have considered the risks of exposure to insulation wool fibres, weighing assessments of hazard by the possibilities of exposure to humans. Each of these groups has considered that the levels of human risk are minimal or non-existent.

Health Aspects

7.1 International Programme on Chemical Safety (IPCS) (1988)

There is no evidence that insulation wool presents any risk by inhalation to production workers today or has done so for the past 20 to 30 years. Criteria Document 77 from the IPCS (1988) states: "It should be emphasised that, at the low fibre concentrations associated with the improved production conditions of the late technological phase, no excess of lung cancer mortality has been observed in the European rock/slag wool workers" . In the general environment, levels of exposure to airborne fibres are several orders of magnitude lower than in the factory situation and no hazard is posed to the public. The IPCS Criteria document concludes that "the possible risk of lung cancer among the general public is very low - if there is any at all - and should not be a cause for concern if the current low levels of exposure continue".

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7.2 International Labour Organisation (ILO) Expert Meeting 2000

The International Labour Organisation Meeting of Experts in January 2000 re-evaluated the recommendations of the 1989 Meeting of Experts. New scientific evidence and available data on research into health aspects of insulation wool published during the decade were taken into account. The outcome of the meeting was a Code of Practice which gives guidance on the safe handling and use of materials .

It was noted that important research had been conducted since the 1989 meeting and that efforts had been made by the industry to improve its products with regard to technological development, chemical composition and physico-chemical properties of insulation wool fibres, in particular as regards their biosolubility. It explicitly referred to existing standards; in particular to the aforementioned EU-classification.

Even for those fibres which do not fall under such a standard, the "Code is a reference document for the development of workplace strategies, policies and mechanisms for dealing with safety in the use of insulation wools."

This Code of Practice has been integrated in the Eurima Code of Practice (2000) for use by manufacturers and users in those countries without relevant national regulations from . This Code is available on request from Eurima.

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8. HEALTH RISKS FROM COARSE, NON-RESPIRABLE INSULATION WOOL FIBRES

Coarse of more than about 5µm in diameter insulation wool fibres may, due to a mechanical reaction, cause itching of the skin. They are not damaging in the way chemical irritants may be. This itching generally abates within a short time after the end of exposure. Fibrous particles in the eye should be treated like other dust particles. When insulation wool products are handled continuously, the skin itching generally diminishes.

Existing skin or respiratory problems could be aggravated by handling insulation wool products as they could be by any nuisance dust.

Good work practice recommends the use of appropriate protective clothing when handling insulation wool products . Pictograms on some product packaging illustrate the recommended good work practices.

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9. DECOMPOSITION PRODUCTS AT HIGH TEMPERATURES

Insulation wool itself does not burn. Main decomposition products of the organic substances in insulation wool products which make only a small percentage by weight are carbon monoxide, carbon dioxide and water. VOC-decomposition products are only formed in negligible traces.

When insulation wool with organic binder is heated to more than about 180°C as in some ovens for example, this starts a decomposition reaction of the binder, the products of which can be detected by their odour. Emissions only occur during the first heating cycle; it is advisable to ensure good ventilation when these appliances are first put into service. Additional information can be obtained from Material Safety Data Sheets for technical insulation products.

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10. CONCLUSIONS

The absence among workers of any established link between respiratory disease and exposure to airborne insulation wool fibres confirms the earlier conclusions drawn by several national and international authorities that insulation wool products pose minimal - if any - risk to humans.

However, just as with any form of dust, avoiding unnecessary exposure to insulation wool dust is prudent. Eurima and its member companies encourage installers and users of insulation wool products to follow the manufacturers' recommendations during handling of these products.

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11. REFERENCES

1. Stanton MF, Wrench C. Mechanisms of mesothelioma induction with asbestos and fibrous glass. Journal of the National Cancer Institute 1972;48:797?821.

2. Pott F, Freidrichs KH. Tumoren der Ratte nach i.p.? Injektion faser? förmiger Stäube. Naturwissenschaften 1972;59:318.

3. JEMRB. Joint European Medical Research Board Information Bulletin. Eurima, Avenue Louise 375, Brussels. 1995.

4. Marsh GM, Enterline PE. Mortality among a cohort of US man-made mineral fiber workers: 1985 follow-up. Journal of Occupational Medicine 1990;32:594?604.

5. Boffetta P, Saracci R andersen A, Bertazzi P A, Chang-Claude J, Cherrie J, Ferro G, Frentzel-Beyme R, Hansen J, Olsen J, Plato N, Teppo L, Westerholm P, Winter P D, Zocchetti C. Cancer mortality among European man-made vitreous fiber production workers. Epidemiology 1997;8:259?268.

6. Marsh G, Stone R, Youk A, Smith T, Quinn M, Henderson V, Schall L, Wayne L, Lee K. Mortality among United States rockwool and slagwool workers: 1989 update. Journal of Occupational Health and Safety - Australia and New Zealand 1996;12:297?312.

7. Hughes JM, Jones RN, Glindmeyer HW, Hammad YY, Weill H. Follow up study of workers exposed to man made mineral fibres. British Journal of Industrial Medicine 1993; 50:658 ? 667.

8. Brown N, Peat J, Mellis C, Woolcock A. Respiratory health of workers in the Australian glass wool and rock wool manufacturing industry. Journal of Occupational Health and Safety - Australia and New Zealand 1996;12: 319?325.

9. Weill H, Hughes J. Review of epidemiological data on morbidity following exposure to man-made vitreous fibres. Journal of Occupational Health and Safety - Australia and New Zealand 1996;12:313?317.

10. Vu V, Barrett JC, Roycroft J, Schuman L, Dankovic D, Baron P, Martonen T, Pepelko W, Lai D. Chronic inhalation toxicity and carcinogenicity testing of respirable fibrous particles. Regulatory Toxicology and Pharmacology 1996;24:202?212

11. IPCS International Programme on Chemical Safety. Environmental Health Criteria 77. Man-made mineral fibres. Geneva, Switzerland: WHO, 1988.

12. Rossiter CE, Chase JR. Statistical analysis of results of carcinogenicity studies of synthetic vitreous fibres at Research and Consulting Company, Geneva. Annals of Occupational Hygiene 1995;39:759?769.

13. Hesterberg TW, Miiller WC, McConnell EE, Chevalier J, Hadley JG, Thévenaz P anderson R. Chronic inhalation toxicity of size-separated glass fibers in Fischer 344 rats. Fundamental and Applied Toxicology 1993;20: 464?476.

14. Bauer JF, Law BD, Hesterberg TW. Dual pH durability studies of man?made vitreous fiber (MMVF). Environmental Health Perspectives 1994;102 Suppl 5:61?5.

15. Bernstein DM, Morscheidt C, Grimm H, Thévenaz P, Teichert U. Evaluation of soluble fibers using the inhalation biopersistence model, a nine?fiber comparison. Inhalation Toxicology 1996;8:345?85.

16. Eastes W, Hadley JG. Role of fiber dissolution in biological activity in rats. Regulatory Toxicology and Pharmacology 1997;20:S104?12.

17. Hesterberg TW, Miiller WC, Musselman RP, Kamstrup O, Hamilton RD, Thevenaz P. Biopersistence of man?made vitreous fibers and crocidolite asbestos in the rat lung following inhalation. Fundamental and Applied Toxicology 1996;29:269?79.

18. Muhle H, Bellmann B. Biopersistence of man?made vitreous fibres. Annals of Occupational Hygiene 1995;39:655-660.

19. Hesterberg TW, Chase G, Axten C, Miiller WC, Musselman RP, Kamstrup O, Hadley J, Morscheidt C, Bernstein D, Thevenaz P. Biopersistence of synthetic vitreous fibers and amosite asbestos in the rat lung following inhalation. A joint study of NAIMA and Eurima. Toxicology and Applied Pharmacology 1998.

20. European Commission. Commission Directive 67/89/EC of 5 December 1997 adapting to technical progress for the 23rd time Council Directive 67/548/EEC. Official Journal of the European Communities, L343/19.

21. International Agency for Research on Cancer. IARC monographs on the evaluation of the carcinogenic risks of humans. Man-made mineral fibres and radon, vol 43. Lyon, France: IARC, 1988.

22. International Labour Office. Code of practice on safety in the use of synthetic vitreous fibre insulation wools (glass wool, rock wool slag wool). Occupational Safety and Health Series No. Geneva, Switzerland: ILO, .

23. Eurima. Code of Practice for Manufacturers and Users of Insulation Wools. Eurima, Avenue Louise 375, Brussels. 2001 (In preparation).

An additional list of references is available from Eurima.