|
 Asbestos
is a naturally occurring fibrous mineral commonly found
in underground rock formations .For commercial purposes,
it is recovered by mining and rock crushing. Fine particles,
invisible to the eye, are present in the air and water
everywhere. All of us may be inhaling them and ingesting
them through drinking water every day for our life times
without any adverse effect on health. Asbestos is commercially
used since 1900 and is classified into two 2 groups. One
category is called "Chrysotile (white) Asbestos and
the other group is termed asAmphiboles consisting ofCrocidolite(blue),
Amosite (brown) etc.
White asbestos
(chrysotile) constitutes 98% of world production for its commercial
use. Indian asbestos cement sheet and pipe manufacturers import
all their requirements of chrysotile fibres from Canada, Brazil,
Russia, Zimbabwe and Kazakhstan for production of AC sheets
and pipes. India imports ony 20% of world production fromabove
countries. Asbestos is also mined in India, but quantity and
quality-wise it is of no relevance to our asbestos cement
production.It is generally found in large concentrations in
the natural bedrock of the earth crust.
The Chemical
composition of Crocidolite, Amosite and Chrysotile are different.
Asbestos
fibre, (composed mainly of magnessium and silica), is a great
reinforcing agent. While its tesile strength is greater than
steel, it has other rare and highly valued fire retardant,
chemical resistant and heat insulating qualities. Infact it
is a magic mineral and no other substituite can match its
properties.
2. What are
Asbestos Cement (AC) Products?
-
Because
of its exceptional strength and ability to cover inside
area as reinforcement only 8.9% of chrysotile fibres are
adequate to combine with cement and other raw materials.
Over 90% of asbestos fibre imports of India go into AC sheet
and pipe production.
-
AC
Sheets have used in India for 70 years. Being weather proof
and corrosion resistant, thesesheets are 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, Russia, China,
Indonesia, Thailand, and Brazil are some of the largest
users of ACSheets.
-
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 cosume 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 rsources.
-
AC
products are manufactured under (ISI) license strictly conforming
to the standards of Bureu of Indian Standards. IS 459/1992
for Corrugated Roofing Sheets, IS2098/ 1997 for Flat Sheets
and IS 1626 (Part 111)/1994 for Roofing Accessories.
3. Explain the negative reports
on asbestos:
-
The
bias against the use of asbestos in a fewcountries is due
to the adverse Western media coverage relating to altogether
different types and usages of asbestos in the past in those
countries i.e.sprayed-on asbestos and friable low-density
asbestos insulation used under uncontrolled conditions at
that time due to lack of adequette scientific Knowledge
ex. usage of amphibole (blue) variety in such applications.
Though these particular usages have since been discontinued
in the West, the claims relating to the past keep appearing
in the media resulting in general confusion. In India Asbestos
Fibre was never used as sprayed insulation.
-
But, once the scientific research into the risks of asbestos
was set in motion, development and installation of pollution
control systems took place, enabling the asbestos mining
and asbestos cement industries to maintain safe and acceptable
levels of dust pollution at the work places.
-
Once
the safety fears were defined, the Governments have stepped
in and laid down pollution control regulations and the mechanisms
to enforce their compliance. Compliance with these regulations
and standards assured the workers in asbestos cement industries
a risk free environment .
For the consumer the asbestos cement products were always
safe.
|
| |
| |
|
 |
