RFM Inc.
Asbestos Compliance	Basic Facts
For Facility Owners	White Paper

No matter where you work or live on this planet, asbestos has probably touched your life in one way or another. Asbestos has long been used because of its unique heat and chemical resistant characteristics. Much has been written over the centuries about this so called miracle mineral, with all of its wonderful traits and unfortunately, its deadly effect on people as has been learned over time. While still being mined and sold today, occupa-tional exposure to asbestos is now widely recognized as a significant health hazard in many industrialized nations. However, that wasn't always the case. This article has been written to provide safety, environmental and maintenance managers with some history about asbestos as well as some basic information about it's nature and why it deserves re-spect. It is intended as a backgrounder for both the novice and experienced professional.

Early uses of asbestos, a word that comes from a Greek adjective meaning inextinguish-able, were observed even before the birth of Christ. Potters in Finland were reported to have used soils containing asbestos dating back to 2500 B.C. Asbestos was used for wicks in sacred lamps as described by several Greek historians. And, in ancient Roman and Egyptian times, writings of the time mentioned asbestos fibers being weaved into burial clothing for cremations of emperors and pharoahs. During the Dark Ages, the use of asbestos seemed to diminish in Europe, however in the 13^th century, Marco Polo discovered several fire resistant cloth materials made out of asbestos, such as tablecoths during his many travels.

Despite these early records of asbestos usage, it wasn't until the late 1800's and the industrial revolution that large scale use of asbestos would occur. With the invention of the steam engine and other modern advances, came greater need for materials to meet the heat and friction demands of the era. Asbestos was the natural choice because it had many of the performance qualities that were needed, it was easy to process, it was cheap, and it was readily abundant. The first asbestos textile mill in the United States started production in 1896. It was also about this same time that health concerns were being discovered. In 1900, a doctor in London performed a post-mortem exam on a man who had worked in an asbestos textile factory for 14 years. Asbestos particles were found in the lung tissue and this may well be the first modern day record making the deadly connection of occupational exposure to asbestos. Around that same time period, H. W. Johns, who founded the H.W. Johns Manufacturing Company (a harbinger to the most well known asbestos manufacturer, Johns-Manville, now in bankruptcy), died in 1898 of dust pneumonitis - known today as asbestosis - (the name of the pneumoconiosis caused by the inhalation of asbestos fibers). However, it wasn't until 1924 that asbestos lung disease would officially be recorded in England by Dr. W.E. Cooke and published in the British Medical Journal. And it wasn't until 1930 that the first case of asbestosis was recorded in the United States via post-mortem exam of an American worker who had been employed in a South American mine. Over the next few decades, more and more asbestos would be mined and fabricated into products by an increasing number of asbes-tos manufacturing companies. It's greatest usage occurred from the 1940's to the early 1970's. Similarly, more and more workers were being diagnosed with lung disorders, yet the fact that asbestos posed a real threat to those who worked with it was allegedly being suppressed by the asbestos manufacturers. But that was all about to change.

In October of 1964, Dr. Irving Selikoff of Mt. Sinai University in New York and his associates, held the first international conference on the "Biological Effects of Asbestos Exposure" sponsored by the New York Academy of Sciences. At this conference, Dr. Selikoff presented the results of several studies. One of those studies examined the health effects of 1,117 asbestos insulation workers at two New York/New Jersey local area unions who worked with asbestos over a prolonged period of time. This study showed radiological evidence of asbestosis in half of the union members and it further proved there was a latency period associated with asbestos exposure. The results demonstrated more workers coming down with asbestos related cancers based on greater amounts of time spent handling these insulation materials, typically 20-30 years of exposure. This conference was a turning point in proving that asbestos was a serious health hazard as well as making it one of the most litigated products in history, the effects of which are still being dealt with today.

Pure and simple, asbestos is a group of naturally occurring minerals. It is composed of calcium and magnesium silicate. Asbestos occurs as veins in rocks and is mined from the ground, similar to coal. The first commercial asbestos mine opened in the Quebec province of Canada in the 1870's. Today it is predominantly mined in Brazil, Canada, China, Russia and South Africa, and to a lesser degree in a few other countries - (See Table 1 on page 12). After asbestos is mined, it typically is then crushed, milled, and when processed and mixed into other materials, takes the form of hollow, microscopic needle-like fibers. They are invisible to the naked eye, yet, are nearly indestructible. That is why asbestos became the material of choice for a variety of uses - (see Common uses of asbestos on pages 4-5).

There are six (6) fibrous minerals that occur naturally in soil and rocks in various areas of the world. The mineralogy and chemistry of these materials can be found in Table 2 on page 13. These six minerals fall into two (2) mineralogical divisions; serpentines and the amphiboles. Chrysotile, (white asbestos), is the most common asbestiform and falls into the serpentine category. Mining company statistics coupled with various government agencies estimate that chrysotile comprises over 90% of all the asbestos used in the world. It is essentially a sheet silicate mineral rolled into itself to form a hollow tube.

The remaining five (5) asbestos types, amosite, (brown asbestos), crocidolite, (blue asbestos), actinolite, anthophyllite and tremolite fall into the amphibole category. Amosite and crocidolite approximately make up the remaining 10% of the asbestos mined. Amosite asbestos was not used as much as chrysotile because is has a lower tensile strength. Crocidolite fibers are shorter and more brittle than chrysotile but they have a very high tensile strength as well as excellent chemical resistant qualities. Both amosite and crocidolite do not wet well with water which has made them difficult to deal with from a removal standpoint. Actinolite, anthophyllite and tremolite are rare asbestiforms and were seldom used. All of these amphibole asbestiforms are similar in their crystalline structure with double-chain silicate ribbons.

All of the asbestiforms are extremely fibrous in nature with exceptional thermal, acoustical and electrical insulation properties. That is why asbestos is useful for commercial applications. Asbestos also exhibits tremendous chemical resistance and its high tensile strength and flexibility as discussed previously makes it a natural choice as a reinforcement or binder in an array of building products. Thus, asbestos fibers have enjoyed widespread use for many years. So much so, that according to a variety of sources, it is estimated there are over 3000 different products that contain asbestos - (See Table 3 on page 14). They can be found in a variety of commercial, industrial and consumer applications, but the greatest usage was in the building construction trades. One of it's earliest uses in the 20^th century was as a surfacing material in buildings. Asbestos was applied on ceilings for its decorative or acoustical qualities. Later on, it became the material of choice as an insulation coating on structural steel beams for fire protection. The greatest usage during the industrial revolution was for its thermal qualities. Asbestos was used in ships, buildings and factories on thermal system insulation, such as pipes, fittings, boilers, tanks, ducts and other components to prevent heat loss. There are also a myriad of miscellaneous applications where asbestos was used. Some examples include floor tiles, ceiling tiles, cement products, roofing products, drywall or wallboard products including joint compounds, gasket and packing materials, adhesives or mastics, laboratory aprons, gloves, as well as automotive and industrial brakes and clutches to name a few of the more common commercial applications. However, asbestos was used in some unusual applications as well. In industry it can be found in soapstone lab bench tops, to old chalkboards to arc chutes in electrical equipment. For consumer use, asbestos can be found in home siding and roofing shingles, in flooring, both tiles and sheet goods and even was used for a while in hair dryers and once upon a time in cigarette filter tips. Needless to say, asbestos can almost be found in every building or insulation product known to man. Its extensive use is one of the reasons it still exists as a hazard today.