TY - JOUR
AU - Angelini,, Alessia
AB - Abstract The asbestos industry has always claimed that asbestos is a ‘magic mineral’, which is not replaceable. New findings, however, contradict this because asbestos-free alternatives, with excellent insulating properties, have been available since the end of the nineteenth century. The aim of this current research is to gather evidence of the potential of ‘Martinite’ to replace asbestos. We identified references to ‘Martinite’ in documents and brochures pertaining to insulation of ships, dating back as far as possible by acquiring recent interviews, utilizing records in public libraries and in archives, and conducting web searches. Martinite was produced by a small company called ‘Manifatture Martiny’, founded at the end of the nineteenth century in Turin, Italy. This company was specialized in insulation materials production, such as cork, rubber, foams, and even asbestos. In the early twentieth century, Martinite was utilized in warships of the Royal Italian Navy. During this time, it was patented in Italy and in many other industrialized nations. It was also utilized in construction of civilian power plants and was approved by the Architects Corporation in 1940. Furthermore, it was licenced in 1950 by the Italian National Naval Certification Body (UNAV) to be used on ships. We argue that had Martinite been properly advertised and distributed, it could have been used worldwide in place of asbestos for some applications, resulting in a lower incidence of serious and fatal diseases. The small scale of the company, compared to those of the asbestos multinationals, contributed to the lack of commercial development of the product. asbestos alternatives, asbestos insulation, asbestos substitutes, cotton silicate, man-made mineral fibres, Martinite, naval insulation; slag wool, thermal insulation, thermal material Introduction During our previous research on exposure to asbestos during shipyard re-construction, we found various documents describing the existence of a material found in thermal insulation and known commercially as ‘Martinite’. We set out to determine whether the insulation containing Martinite was ordinary asbestos material. Upon learning that Martinite did not contain asbestos fibres, we decided to deepen our research. Martinite was produced by a small factory near Turin, Italy, towards the end of the nineteenth century, and its name was derived from the name of the company, Manifatture Martiny. The current research was accomplished through consulting public libraries and archives, as well as through analysing web-based resources. It is clear from the research, that Martinite was an asbestos-free material with excellent insulating properties and without negative impacts on human health. Had it been used more widely, the widespread use of asbestos could have been avoided in many applications. Methods A Martinite sample was not available for current laboratory analysis, but a technical specification document definitively clarified that this insulator did not contain any asbestos. The Municipal Library of Turin and the State Archives located in the same city were consulted alongside online research both for text and images. The keywords used were martinite, mineral thermal insulators/insulation, patented thermal insulators/insulation, asbestos-free thermal insulators/insulation, and slag wool. The research continued also in PubMed with the keywords ‘martinite’ and ‘slagwool’. Contacts with Occupational Health and Safety Units in Genova and Turin were established. Genova has been and remains home to numerous and important shipyards. Of major importance was establishing contacts and interviews with former employees of the manufacturing company (Manifatture Martiny) to verify and more clearly understand the composition of the product, the manufacturing methods, and the commercialization of the insulation. Results The manufacturer of Martinite was the company Manifatture Martiny funded and based in Turin from 1875 until 1986. The content of a standard letter to the customers [see Letter to customers Object: Caratteristiche Tecniche Martinite Manifatture Martiny (unpublished data), supplement file n. 1, available at Annals of Work Exposures and Health online] reveals that Martinite was composed of slag wool, obtained from blast furnace and starch used as a binder (Deutsches Patent und Markenamt, 1912). The company ‘Manifatture Martiny’ did not produce slag wool, but bought it from a supplier. Chemically, Martinite was mainly composed of amorphous silica (SiO2 36%), calcium oxide (CaO 45%), aluminium oxide (Al2O3 14%) plus a series of other oxides (metals + oxygen) depending on the starting raw material (see supplement file n. 1, available at Annals of Work Exposures and Health online). The manufacturing method was as follows: the slag wool fibres were dispersed in a starch aqueous solution and the suspension, after homogenization, was drained to the bottom of the container through a strainer, forming a panel which could be subsequently cut to size or modelled. The drying phase completed the process. The products were placed on the market in the form of panels of various thicknesses or coatings for pipes (Deutsches Patent und Markenamt, 1912). Martinite turned out to be an excellent thermal insulation because its fibrous structure captured a considerable quantity of air and it was suitable to resist at temperatures of about 500°C (see supplement file n. 1, available at Annals of Work Exposures and Health online). The cost of this material, as well as for the other insulation, was proportional to the thickness, which determined the insulation capability and consequently the temperatures to be maintained. Although a Martinite sample was not available for current laboratory analysis, in the Catalog n. 4, part of the Company documentation found in the Municipal Library of Turin (Manifatture Martiny Catalogo 4, 1915), the technical specification definitively clarified that this insulator did not contain any asbestos. In the same document, values referred to the thermal conductivity, the aptitude of a material to transfer heat, expressed as calories (per hour per m2) for each thermal insulating material and the relative marketing prices are reported. The data in Table 1 show that Martinite had a density much lower than asbestos and other insulating materials. From another document we know that Martinite could also be produced with much lower densities, even down to 140 kg m−3 (Museo di Torino, 1929, p. 94) so greatly increasing its insulating power. By calculation, it appears that an asbestos mattress, for instance, needs to be almost double the thickness of a Martinite board to achieve the same effect in terms of insulation. These considerations suggest that the lower weight of the material had considerable advantages, for example, in naval uses and in economic aspects. Table 1. Thermal insulation characteristics and costs of some insulation material. Thermal insulation . Cala . Lire/Euro m2b . Martinite 300 kg m−3 1.70 16.50/58 Magnesia–asbestos 1.44 Diatomaceous earth 2.15 Asbestos flock 3.00 Asbestos mattress 570 kg m−3 3.28 15.25/54 Asbestos textiles 4.12 Thermal insulation . Cala . Lire/Euro m2b . Martinite 300 kg m−3 1.70 16.50/58 Magnesia–asbestos 1.44 Diatomaceous earth 2.15 Asbestos flock 3.00 Asbestos mattress 570 kg m−3 3.28 15.25/54 Asbestos textiles 4.12 aThe value indicates the number of calories transferred per unit of surface (m2) and time (h), when the difference of temperature between the faces is 1°C for a constant thickness of 40 mm. bYear 1915 Italian Lire converted into Euros (inflationhistory.com, available at http://inflationhistory.com, accessed November 2019). Open in new tab Table 1. Thermal insulation characteristics and costs of some insulation material. Thermal insulation . Cala . Lire/Euro m2b . Martinite 300 kg m−3 1.70 16.50/58 Magnesia–asbestos 1.44 Diatomaceous earth 2.15 Asbestos flock 3.00 Asbestos mattress 570 kg m−3 3.28 15.25/54 Asbestos textiles 4.12 Thermal insulation . Cala . Lire/Euro m2b . Martinite 300 kg m−3 1.70 16.50/58 Magnesia–asbestos 1.44 Diatomaceous earth 2.15 Asbestos flock 3.00 Asbestos mattress 570 kg m−3 3.28 15.25/54 Asbestos textiles 4.12 aThe value indicates the number of calories transferred per unit of surface (m2) and time (h), when the difference of temperature between the faces is 1°C for a constant thickness of 40 mm. bYear 1915 Italian Lire converted into Euros (inflationhistory.com, available at http://inflationhistory.com, accessed November 2019). Open in new tab In Catalog 4 it is stated that Martinite had been patented not only in Italy, but also in the other main European countries and won a Gold Medal in Grand Prix 1910 London Exhibition. In particular, in the brochure, the Italian patent (Beniculturali.it, available at http://dati.acs.beniculturali.it/mm/local/-”72549, accessed November 2019) and the German one (Deutsches Patent und Markenamt, 1912) are quoted. The original German patent document contains a summary description of the Martinite preparation method and explains that asbestos fibres could be added to Martinite on request of customers. Obtaining a patent demonstrates the originality of the product and that it was not an imitation of something invented before. However, Martinite was not widely known, particularly outside of Italy. In a compendium of asbestos alternatives published on behalf of the Society of Chemical Industry, which lists scientific publications between 1977 and 1988 Martinite does not appear (Hodgson, 1989). Furthermore, there are not any citations in the Materials Handbook (Brady and Clauser, 1977), first published in 1929, listing nearly 14 000 materials and products. These facts show that this Martinite was not well known outside the Italian borders, despite the patents held in other countries since the beginning of the twentieth century. In a book entitled ‘Asbestos: medical and legal aspects’ a long list of asbestos-free material is quoted (Castleman, 2005). Neither Martinite nor the manufacturer, Manifatture Martiny, is listed even though Martinite was patented by this time. It is interesting to note in the list that prior to 1900 there were only two types of non-asbestos insulation materials produced by Manville Corporation (USA). Both contained wood pulp and dust plus other organic and inorganic components. It is presumable that given these organic components the operating temperatures would have been quite low and easily degradable compared to Martinite. The patented asbestos-free materials and producers increase after 1920 and reach the maximum during the second half of the twentieth century. All this demonstrates that Martinite would have been a worldwide competitive insulation since the end of the nineteenth century. The first reported industrial use of Martinite involved shipbuilding, and its use is quoted in the shipbuilding company Catalog 4. It includes a list of warships of the Royal Italian Navy (insulated with Martinite) built from 1890 up to 1914 in the shipyards of La Spezia, Livorno, Castellammare di Stabia and Venice. This Catalog is presented (Fig. 1). Figure 1. Open in new tabDownload slide List of warship of the Royal Italian Navy insulated with Martinite). Figure 1. Open in new tabDownload slide List of warship of the Royal Italian Navy insulated with Martinite). In other brochures [see Advertising Brochure—Manifatture Martiny (unpublished data), supplement file n. 2, available at Annals of Work Exposures and Health online], the approval of RINA (Italian equivalent to British Lloyd’s of London Insurance company), following laboratory tests, was approved for use on fire protection bulkheads. Additional evidence in support of the quality of Martinite was confirmed by laboratory tests conducted in June 1976 by the chemical laboratory Grandi Motori-Slem of Trieste [see Laboratory Test Report RG 4680—GMT Trieste 1st June (unpublished data), supplement file n. 3, available at Annals of Work Exposures and Health online], a company where large marine engines are produced. These test reports state that Martinite, when compared to the asbestos-based product Capisolite, is equivalent in terms of thermal insulation for temperatures up to 300°C and it is better for the effects of soluble sulphates, therefore less hygroscopic. In a document issued in 1950, the ‘UNAV’ (technical unification office in the naval field), a subsection of UNI (National Unification Body), sent the test results of a sample of a fire door to Manifatture Martiny [see UNAV Report U/8336-05/04/1950 Genova (unpublished data), supplement file n. 4, available at Annals of Work Exposures and Health online]. It was a sandwich metal fire door packed with Martinite as insulation. The report quotes the various laboratory test condition and the operating temperatures. The results are as follows: (1) The vegetable cotton adhering to the external surface of the door did not ignite. (2) The temperature measured at the external surface of the door was 120°C while on the internal surface was 815°C. (3) No permanent deformations worthy of note were found in the door. The conclusions are as follows: (1) It is believed that the structure of the door is adequately robust to withstand a heat action intensity of 815°C, as established by the Italian Regulations and the 1929 London Convention (SOLAS). (2) The thickness of the insulating material, and therefore of the door, is sufficient to prevent the spread of a fire for 1 h, as established by the aforementioned regulation. These laboratory tests were performed on 9th and 10th November 1948. In ‘Architettura: journal of the national fascist architects union’, several building materials are presented (Architettura, 1940). This issue of the journal reports the results of an exhibition held in Rome in 1940 where ‘following the goal drawn up by Il Duce to achieve the absolute independence of our country from foreign imports, we can say that autonomy has now become for Italian National Industries their main principle’. The pictures of pipe linings and insulating boards of several thickness manufactured with Martinite are presented in this journal. Searching online with the keyword Martinite there are 68 700 results but very few of interest. Many results regard the mineral Martinite (mindat.org, available at https://www.mindat.org/min-26345.htm, accessed November 2019) (McDonald and Chao, 2007) which is a completely different material. The raw material from which Martinite was made was not a mineral, but just blast furnace slag. One interesting report was found in an Australian newspaper. It was an advertisement, published in 1954, of Lauro Navigation Fleet offering a passenger service to migrants from Italy to Australia on board turbo vessels (TV). The ship ‘Sidney’ was marked with an asterisk and the footnote explained: New Luxury Liner, the safest afloat–being fitted throughout with ‘Martinite’ (the latest and most efficient fireproof material (trove.nla.gov.au, available at https://trove.nla.gov.au/newspaper/article/18439479, accessed November 2019). Entering in Pubmed with the exact word ‘Martinite’ no references are found. Further research on the field was developed, finding that the turbovessel (TV) Sidney was transformed and refurbished in Genova, at the OMSA Shipyard around 1950. The investigation was then extended to Genova and through the Occupational Health and Safety Unit, contact with the former owner of the OMSA shipyard, now retired, was established. During the meeting, he confirmed the use of Martinite during the TV Sidney refurbishing, also providing a photo of the ship (Fig. 2) and the interiors under renovation (Fig. 3). Figure 2. Open in new tabDownload slide Turbo Vessel Sidney moored in the Port of Genova. Figure 2. Open in new tabDownload slide Turbo Vessel Sidney moored in the Port of Genova. Figure 3. Open in new tabDownload slide Interiors of Turbo Vessel Sidney during renovation and Martinite panels in the upper part of the photo. Figure 3. Open in new tabDownload slide Interiors of Turbo Vessel Sidney during renovation and Martinite panels in the upper part of the photo. Another reference about this fireproof characteristic has been found in the book ‘Australian Migrant Ships’ (Plowman, 2006). On page 97 the author, about the TV Sidney and Roma, her twin, writes: ‘Due to extensive use of a new non-flammable lining called mar(t)inite, they were called the ships that cannot burn, but unfortunately this claim was never put to the test’. In the book issued in 1929 in Turin (Museo di Torino, 1929, p. 94) describing the story of the new Hospital ‘San Battista’ a description of the company ‘Manifatture Martiny’ and the product Martinite has been found: ‘The Company, founded in 1875, was the first in Italy to treat and manufacture thermal and sound insulating units. Thus an industry was created which now boasts the pride of being the most modern, the most complete and the most important of its kind in Italy, manufacturing the complete range of thermal insulators for any application…. The famous Martinite was then created, a patented, incombustible felt. Born with a weight of 350 kg/m3and with a conductivity of about 0.06, we have arrived, with the continuous search for the best done by expert engineers during decades of studies in the well-equipped laboratories of the Company, to produce a Martinite of only 140 kg/m3, and a conductivity coefficient 0.036. This insulation is suitable for temperatures up to 500°C. It’s manufactured in pipe linings and plates of various sizes and thicknesses……Therefore the MANIFATTURE MARTINY were entrusted with the insulation of several thousand meters of piping of the important sanitary systems, all those in the laundry department of the hospital. The MANIFATTURE MARTINY have a special organization for carrying out isolations on ships. Thus, on the most important units of the merchant navy, similar isolations were carried out, in addition to the covering of the fire-rated bulkheads, with the non-combustible Martinite felt, approved by the Royal Italian Registry’ In the public records of the Eternit trial (Turin Tribunal 2010–2014), which has now been completed, two declarations have been found: a former manager and a worker, both from Manifatture Martiny. Here an excerpt of their statements: A.G employed in Manifatture Martiny 1947–1982 ‘Martinite was a mineral wool with starch used as a glue, it was made by re-using slag from Fiat blast furnaces. The Martinite was produced before I was hired by the company. In essence, Martinite was a material that was proposed, on the market, as an alternative, to glass wool and asbestos, in fact the competition between our and other companies that produced asbestos or glass wool was quite fierce. The feeling was that our product was, in some way, an annoyance in terms of market competition and perhaps this is the reason why the company has failed, I think, at the end of the 80s. As for the costs I do not remember precisely, but Martinite did not differ so much from other products on the market. The production process consisted in mixing mineral wool with starch as an agglomeration and in the realization of slabs of 50×100 cm and pipe laggings 50 cm long but the production capacity was limited.’ S.G worked during the last 15 years of the company’s activity. On the shutdown, he provides a different motivation: ‘Company managers weren’t inclined to invest in upgrading machinery to the latest technologies. Slowly the competition succeeded in conquering the buyers’ market due to a question of prices that Martiny couldn’t keep down by working with outdated technologies’. The German patent attests that the binder was starch and this was confirmed by the former employee. This was the nodal point and an innovation developed by Manifatture Martiny for the use of slag fibres in the form of mouldable products at the end of Nineteenth Century when synthetic binders weren’t yet been developed. As far as the toxicological characteristics are concerned, Martinite had two components: slag wool fibres and starch. The first has an irritant effect on skin and mucosae. Its possible carcinogenicity for the respiratory tract was first evaluated by IARC in 1988 (Volume 43—1988) and classified in the Group 2B (possibly carcinogenic) and shifted in the Group 3 (not classifiable as to its carcinogenicity) in 2002 (Volume 81—2002). Starch does not present particular risks to human health (Crincoli, 2016) and has been also used as a food additive. No samples of Martinite are stored in Turin Politecnico (Prof. Clerici C., personal communication), but research is still in progress. Discussion One of the problems we faced during our historical research on this insulation material was the lack of a sample. Knowledge of its composition derives from paper documentation and from a declaration of a former employee. It appears that neither the ships insulated with Martinite, nor the industrial plants, such as the thermal plant of the Hospital of Turin, currently exist (Fig. 4). Figure 4. Open in new tabDownload slide Thermal plant—Hospital ‘San Battista’—Turin. Figure 4. Open in new tabDownload slide Thermal plant—Hospital ‘San Battista’—Turin. The production company, Manifatture Martiny, shut down in 1986 which results in an important question. Since the production company was the owner of the patent and had been producing Martinite as an asbestos-free insulator for years, the company closed at approximately the same time when the carcinogenic impacts of asbestos were becoming widely known. Why did the company not flourish in this period, but instead, shut down? One of the hypotheses on the loss of the commercial war against asbestos is simply related to the size and production capacity of Manifatture Martiny. The large multinational companies producing asbestos had greater production capacity, and therefore, won the asbestos/Martinite trade war. Another reason for the poor development of Martinite emerged in the statements of a former employee: the owner was poorly inclined to invest in the renewal and technological upgrading of the company’s plants. It should be noted that the production did not concentrate solely on Martinite, but it was spread along a whole range of Manifatture Martiny products. Hypothetically, it would have been improbable to satisfy an increase in demand. The starch was the key component of Martinite (see supplement file 5, available at Annals of Work Exposures and Health online). Slag wool cannot be kept together to form solid items without a binder. Manifatture Martiny found the solution in starch during an era when artificial binders had not yet been developed. According to Hartung, the first commercial manufacturing of slag wool took place in 1880. Its use as insulation started in the first two decades of the twentieth century, but a substantial increase came only after the World War II. Dust suppressors, like binders, were developed only during the 1940s (Hartung, 1982). In the book Australian Migrant Ships 1946–1977 (Plowman, 2006) on page 97, a material error must be reported in terms of spelling. The author writes ‘Marinite’ instead of ‘Martinite’. This caused confusion as Marinite was an asbestos-containing product used in the naval field and contained crocidolite and amosite asbestos fibres. Marinite was produced by Johns-Manville company, that owned a registered trademark (Brady and Clauser, 1977). Conclusions Manifatture Martiny was founded in 1875. Already in 1890, the Company developed the thermal insulation material called Martinite, which was used in the insulation of the Marco Polo warship built in the shipyard of Castellammare di Stabia (Napoli). The insulation made with Martinite continued also in the civil field, being installed in several thermal power systems. The company presented and obtained patents in Italy and in other major industrialized countries of Europe. It also won a prize in England for performance at the beginning of the twentieth century. Nevertheless, the product was basically unknown at the worldwide level. In 1950, the insulation was approved for use in naval fire doors and in 1976 a laboratory test claimed that Martinite behaves better than Capisolite, an asbestos insulation. For Manifatture Martiny, starch was the nodal point for the use of slag fibres in the form of mouldable products at the end of nineteenth century when synthetic binders weren’t yet been developed. For commercial reasons and due to poor technological renewal of the company, Martinite was no longer produced just as its star could have been rising. Its commercial expansion could have had an important development due to the banning of asbestos in Italy and later in Europe; instead, the company closed. The serious and fatal consequences on the health of hundreds of thousands of workers in many sectors of industrial production could have been avoided. Acknowledgments Benedetto Terracini, University of Turin, Nicola Ranieri, Solvay Specialty Polymers Italy Milano for their invaluable contribution in the drafting of the text. Tony Fletcher, LSHTM London, and Janna C. Merrick Ph.D., Professor of Politics at University of South Florida Tampa (USA), for their contribution reviewing and assisting in English translation. Francesco Carnevale occupational physician, Maria Teresa De Palma archivist and Daniela Caffaratto Sovrintendenza Archivistica del Piemonte for their help in consulting public libraries and public archives. Declaration Both authors Stefano Silvestri and Alessia Angelini have acted as expert witness for Public Prosecutors and Judges in litigation concerning victims of occupational diseases and may in future serve as an expert witness in court proceedings related to the same matter. References Architettura: rivista del sindacato nazionale fascista architetti . ( 1940 ). Annata XIX–Maggio 1940–XVIII–Fascicolo V°. Inv 100045 Facoltà di Architettura Firenze—Biblioteca coll. R12 . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC Brady GS , Clauser HR . ( 1977 ) Materials handbook . XI edn. New York: McGraw-Hill Book Company . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC Castleman B . ( 2005 ) Asbestos: medical and legal aspects, 5th edn. New York: Aspen Publishers . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC Crincoli CM . 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New York, USA : McGraw-Hill Book Company , Section 3: Physical and chemical data. p. 260 . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC Plowman P . ( 2006 ) Australian migrant ships 1946–1977 . Australia : Rosemberg Publishing Pty Ltd . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC © The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Martinite: An Alternative to Asbestos Insulation Available Since the Nineteenth Century
JO - Annals of Work Exposures and Health (formerly Annals Of Occupational Hygiene)
DO - 10.1093/annweh/wxz081
DA - 2020-01-01
UR - https://www.deepdyve.com/lp/oxford-university-press/martinite-an-alternative-to-asbestos-insulation-available-since-the-9q1Cg9Rmdh
SP - 5
VL - 64
IS - 1
DP - DeepDyve
ER -