Myths and facts of fibre cement products
| MYTHS: | FACTS: |
| 1 – Fibre Cement is a dangerous material. | – Fibre Cement is completely safe. It is not corrosive, reactive, ignitable or toxic. |
| 2 – Inhalation of even one fibre of Fibre Cement is harmful. | – Thousands of Fibre Cement fibres, invisible, are inhaled by us every day from natural resources and cleared off by natural clearance mechanisms without harm. Fibre Cement has only 7-9% Fibre Cement fibre that is bound with cement and cannot be released into the air. Even if any fibre is released, its chemical characteristics change because of bonding with cement and it cannot be called Fibre Cement fibre |
| 3 – Fibre Cement water pipes cause colonic carcinoma and other diseases. | – Fibre Cement fibres in water are ingested without any harm whatsoever. Therefore the AC water pipes pose no threat. Even the World Health Organization permits the use of Chrysotile Fibre Cement pipes. |
| 4 – Developed countries have banned Fibre Cement products. Only poor countries need it | – No prohibition of Fibre Cement products in over 77% of world nations. |
| 5 – Fibre Cement production is banned in the USA | – The US Court of Appeals rejected a proposed ban on scientific grounds. Fibre Cement products are not banned in the USA. |
What is chrysotile Fibre?
Chrysotile fibre is a naturally occurring mineral found in underground rock formations. It is also known as white Fibre Cement. For commercial purposes, it is recovered by mining and rock crushing. “Fibre Cement” was a commercial term given to a collective group of 6 naturally occurring minerals whose crystals occur in fibrous forms. Though commonly referred as “Fibre Cement” these 6 silicate minerals come from two distinct groups and are chemically and mineralogically different. There are two distinct varieties of Fibre Cement (i) Serpentines (Chrysotile white Fibre Cement) and (ii) Amphibole variety comprised of Amosite, (brown Fibre Cement), Crocidolite (blue Fibre Cement), Tremolite, Actinolite, and Anthophyllite, Mining, production and usage of Amphibole variety of Fibre Cement have been prohibited all over the world for decades ago as they were considered unsafe.
Only Chrysotile variety of fibre (white Fibre Cement), which is considered safe to use under controlled conditions, is in commercial use now. Indian Fibre Cement sheet and pipe manufacturers also use only Chrysotile variety which incidentally is all imported mostly from Russia, Kazakhstan and Brazil.
Chrysotile Fibre Cement fibre is also mined in India in minuscule quantities and so is not of any consequence.
Chrysotile Fibre Cement fibre, (composed mainly of magnesium and silica), is a great reinforcing agent. While its tensile strength is greater than steel, it has other rare and highly valued fire-retardant, chemical-resistant and heat-insulating qualities. In fact, it is a magic mineral.
Fine fibres, invisible to the eye, are present in the air and water in almost every region of the globe. Hence, all of us may be inhaling and also ingesting them through drinking water every day.
Chrysotile fibre is a naturally occurring mineral found in underground rock formations. It is also known as white Fibre Cement. For commercial purposes, it is recovered by mining and rock crushing. “Fibre Cement” was a commercial term given to a collective group of 6 naturally occurring minerals whose crystals occur in fibrous forms. Though commonly referred to as “Fibre Cement” these 6 silicate minerals come from two distinct groups, which are chemically and mineralogically different. There are two distinct varieties of Fibre Cement (i) Serpentines (Chrysotile white Fibre Cement) and (ii) Amphibole variety comprised of Amosite, (brown Fibre Cement), Crocidolite (blue Fibre Cement), Tremolite, Actinolite, and Anthophyllite, Mining, production and usage of Amphibole variety of Fibre Cement have been prohibited all over the world for decades ago as they were considered unsafe.
Only Chrysotile variety of fibre (white Fibre Cement), which is considered safe to use under controlled conditions, is in commercial use now. Indian Fibre Cement sheet and pipe manufacturers also use only Chrysotile variety which incidentally is all imported mostly from Russia, Kazakhstan and Brazil.
Chrysotile Fibre Cement fibre is also mined in India in minuscule quantities and so is not of any consequence.
Chrysotile Fibre Cement fibre, (composed mainly of magnesium and silica), is a great reinforcing agent. While its tensile strength is greater than steel, it has other rare and highly valued fire-retardant, chemical-resistant and heat-insulating qualities. In fact, it is a magic mineral.
Fine fibres, invisible to the eye, are present in the air and water in almost every region of the globe. Hence, all of us may be inhaling and also ingesting them through drinking water every day.
Fibre Cement Products
These products, also commonly known as AC (Fibre Cement) products, are made with a mix of Chrysotile fibres (9%), cement (about 40%), Fly Ash (about 30%) and the rest being wood pulp and water. Over 95% of Chrysotile Fibre Cement fibre imports of India go into Chrysotile Fibre Cement sheet and pipe production.
AC Sheets have been used in India for over 80 years. Being weather-proof, fire-resistant, non-combustible, and corrosion resistant, these sheets are durable practically ageless and maintenance-free, whereas metal sheets corrode and deteriorate with age and exposure.
AC Sheets have also proven to be the most cost-effective, easy-to-install, strong and durable roofing material for warehouses, factories, low-cost housing, and practically any structure needing a roof. Apart from India, other developing countries – China, Russia, Brazil, Indonesia, Thailand, and Vietnam are also large users of AC Sheets.
AC sheets and pipes, being corrosion and erosion-free, once properly laid and jointed, need no maintenance or replacement. They are also very cost-effective.
AC products, which consume low energy in manufacture and do not in any way deplete the natural resources, meet the needs of the country in its developing economy in the context of rapidly rising population and limited resources.
AC products are manufactured under licence strictly conforming to the specifications of the Bureau of Indian Standards. IS 459/1992 for Corrugated Roofing Sheets. AC Pressure Pipes are covered by IS 1592/2003.
Comparison of Fiber Cement sheets with colour coated metal sheets and galvanized aluminium sheets
Fibre Cement sheet
Colour coated metal sheets
Galvanized aluminum sheets
S.No. | Characteristics | Fibre Cement sheet | Colour coated metal sheets | Galvanized aluminium sheets |
| 1 | Life Span(Years) | 50 yrs (Min) Non-Corrosive | Data not available. | 10-15 yrs |
| 2 | Maintenance | NIL | NIL | |
| 3 | Fire Rating | Fire Retardant and Non Combustible | Tendency to twist and melt | Tendency to twist and melt |
| 4 | Thermal Insulation | Good | Poor | Poor |
| 5 | Accoustic Rating | Good | Poor | Poor |
| 6 | Absorption of Rain and Wind Noise | Good (deadens these noises) | Poor | Poor |
| 7 | Energy Required in Production | 16 | 124 | 69 |
| (Kilowatthours(kwh)/SQ.M) | ||||
| 8 | Man Power | Intensive | Low | Low |
| Employment Potential | ||||
| 9 | Wind Resistance | Good | Poor | Poor |
| When Installed | ||||
| 10 | Weather Effect | None | Surface oxidation | Corrosion at drilled holes and where galvanizing is cracked |
| 11 | Bimetallic Reaction | None | Present in contact with | None |
| concrete and other metals | ||||
| in presence of moisture | ||||
| 12 | Condensation | Low and will not effect sheet | High and will result in corrosion | High and will effect sheet |
| 13 | Effect of High Winds | Minimum | Rattling sound | Unacceptable rattling sound |
| 14 | Noise Level | Low | High | High |
| 15 | Protective Coating | Not required | Required to avoid direct | Not required |
| Contact with cement, limesoil, Iron, copper, etc. | ||||
| 16 | Storage | Can be stored in open space at work site | Needs closed go-down for storage to avoid weather assaults | Needs closed go-down for storage to avoid weather assaults |
| 17 | Coverage Efficiency | Approx. 50% higher than GC and Aluminium Sheets. | Effective laid area becomes only 67% as compared to AC Sheets. | Effective laid area becomes only 67% as compared to AC Sheets |
| 18 | Cost | Low | Highest | High |
STUDIES UNDERTAKEN IN INDIA
2001 – Central Labour Institute (CLI) conducted an Occupational Health and Environmental Study in M/s Visaka Industries Ltd., Medak Dist., Andhra Pradesh -established in 1985.
A total of 99 workers were subjected to medical examinations and investigations and the study revealed no cases of possible Fibre Cementis out of the workers examined.
2002 – Central Labour Institute (CLI) conducted Occupational Health and Environmental Study in M/s Hyderabad Industries Ltd., Jasidih, Jharkhand – established in 1979.
A total of 82 workers were examined and the study revealed no cases of possible Fibre Cementis out of the workers examined.
2003 – Regional Labour Institute (RLI) conducted Occupation Health studies at M/s UAL Bengal, and at M/s Neelachal Resource Pvt.Ltd., both in Midnapore, West Bengal. These units were established in 1999 and 1997 respectively.
A total of 101 workers were subjected to general medical examination and investigations through random sampling. In both these units no cases of Fibre Cement related disorder were diagnosed during the conduct of the study.
2004 – The Central Labour Institute (CLI) conducted a National Study on Health Status of Workers in the Fibre Cement Industry”. This study was carried out in 8 Chrysotile industrial units out of which 5 units were manufacturing Fibre Cement Products using Chrysotile and other 3 units were engaged in manufacture of brake linings.
A total of 702 workers in the age groups of 20 to 50 years who were subjected to exposure between 6 to 20 years were studied. No established cases of Fibre Cementis were detected during the Study.
2005 – CLI conducted a National Study on Status of Work Environment in Fibre Cement Products Manufacturing Industry- Evaluation of Airborne Fibre Cement Fibres. This study was carried out in 12 units, 6 units manufacturing Fibre Cement Sheets, 3 manufacturing Fibre Cement Pipes and 3 units manufacturing Friction materials and other products like, brake assembly and millboard. All these units were using Chrysotile fibre.
The study concluded that concentrations of airborne Fibre Cement fibres in 75% of the units studied (manufacturing Chrysotile cement products) were less than 0.5 f/cc while remaining 25% units manufacturing friction materials and other products, the concentration of airborne fibres were between 0.5f/cc to 1f/cc, but nowhere the fibre concentration exceeded the PLE of 1f/cc.
2012 – The study conducted by NIOH found that the fibre levels were found to be lower than the national permissible levels and that all of the organized factories were using protective measures for the control of occupational and environmental health hazards.
CONCLUSION
From the above, it can be observed that in the studies undertaken during the period 2001-2012, no issues related to Fibre Cement were detected among the workers in the units manufacturing products using Chrysotile variety of Fibre Cement.