Asbestos Information

Asbestos SourcesThe best source of asbestos information and lead regulations in the State of Maine is the Maine Department of Environmental Protection in Augusta, Maine. They can be reached by calling (207) 287-2651. You can also reach them through their website.

 

Maine DEP Website 

Asbestos InformationA. Characteristics

1. Asbestos is the common name for a group of fibrous, mineral silicates, having unique properties.
2. These properties include:
   a. Noncombustible
   b. High tensile strength
   c. Good noise absorption
   d. Thermal insulator
   e. Condensation control
   f. Resistant to the effects of corrosive chemicals
   g. Resistant to the effects of friction
3. The various types of asbestos, their characteristics, and uses are given in Table I.

B. Historical Uses

1. Asbestos has been used for over two thousand years. The meaning stemmed from the Greek word "quenchable" - derived from the observation that the material would not burn.
2. Marco Polo reported the use of asbestos in gun powder by the Chinese.
3. A tablecloth belonging to Charlemagne was woven with asbestos.
4. In 1729, Benjamin Franklin sold a purse fabricated with asbestos to his British benefactor.

C. Modern Uses

1. The unique characteristics of asbestos have resulted in a very diverse use of the material over the years. The asbestos industry reports that currently over 3,600 products contain asbestos.
2. Asbestos-containing products can be divided into two categories:
   • Category I - Friable Material and Asbestos Textile Products
   • Category II - Nonfriable Matrix-Bonded Composite Products
3. Table II lists categories, product uses, and approximate dates of use

D. Trade Names

1. Listed in Table III are the types of application and the associated trade names of some asbestos-containing products

E. Methods of Application

1. Sprayed-On
   • Asbestos was sprayed onto structures in auditoriums, hallways, and classrooms for fireproofing, noise absorption, condensation control, and decorative purposes.
   • Sprayed-on asbestos is usually friable.
   • Two methods were used to spray-apply asbestos:
     1. Wet Method
        • Generally, a mixture might have consisted of a slurry of one or more of the following: asbestos (5-30%), mineral wool, and/or fiberglass, and Portland cement, gypsum, pearlite and vermiculite.
        • This material was more dense and less friable than that applied by the dry method (described below).
        • The thickness of the application usually ranged from 1/2 to 1 inch.
        • Chrysotile was usually used in the formulation.
        • The surfaces were often trowelled after application, resulting in a harder, more dense material.
     2. Dry Method
        • Generally, a mixture consisted of a dry blend of asbestos fibers (5-90%) and one or more of the following: mineral wool or fiberglass, Portland cement or gypsum, water-soluble resins, starches, and other additives.
        • The mixture was applied with a sprayer and wetted as it passed through the nozzle. The water activated the water-soluble resins, producing a wet fiber matrix, which readily adhered to the application surface.
        • The thickness of the application was usually 1/2 to 2 inches.
        • Amosite, chrysotile, or both were often used; Crocidolite was used infrequently.
        • Because of the method, the asbestos content can vary greatly within the same application.

   2. Pipe and Boiler Insulation

   1. a. This insulation is usually applied by pasting preformed blocks or sheets or by applying wetted asbestos-containing compounds.
   2. b. Generally, three types of insulation were used:
      • Preformed sections, blocks or siabs
      • Insulating cement for values, elbows or over fiberglass ducts
      • Asbestos paper products (flat sheets or corrugated).

F. Airborne Asbestos

1. Unlike many man-made fibers, asbestos as it is mined and used in manufacturing rarely is in single-fiber form. It can continue to split into smaller and smaller fiber bundles.
2. The average fiber diameter ranges from 0.11 to 0.24 micrometers. However, asbestos can split into even smaller bundles,which cannot be seen with an optical microscope.
3. These fine fibers settle from the air very slowly. In completely still air, fibers of the size usually found in overhead spray insulation in a occupied 8' or 10' office take approximately 80 hours to settle.

 

Table I

Scientific Name	Characteristics	Source
Chrysotile	White asbestos; fine silky fibers; flexible and high tensile strength; accounts for over 90% of the uses of asbestos.	Canada Soviet Union
Amosite	Brown asbestos; brittle fibers; bonds well with plastics and is used in heat insulation materials.	South Africa
Crocidolite	Blue asbestos; strongest of the asbestos fibers; brittle fibers; usually found in combination with chrysotile in pipes and sheeting; also occasionally found with amosite or chrysotile in pipe and boiler wrap; also used as decorative material.	South Africa
These three are types of asbestos most often found in construction materials and commercial products. Tremolite, actinolite, and anthophyllite are also asbestos minerals, but rarely found in building and commercial products.

 

Table II

Scientific Name	Characteristics	Source	Source	Source
Surfacing Material	sprayed-on or troweled-on	1-95	1935-1970	Sodium silicate, portland cement, organic biners.
Preformed thermal insulating products	batts blocks and pipe covering 85% magnesia	15	1926-1949	magnesium carbonate
Textiles	cloth blankets (fire)	100	1910-present	none
	felts	90-95	1920-present	cotton wool
	felts: blue stripe	80	1920-present	cotton
	felts: red stripe	90	1920-present	cotton
	felts: green stripe	95	1920-present	cotton
	sheets	50-95	1920-present	cotton wool
	cord/rope/yarn	80-100	1920-present	cotton wool
	tubing	80-85	1920-present	cotton wool
	tape/strip	90	1920-present	cotton wool
	curtains: theatre/welding	60-65	1945-present	cotton
Cementitious: concrete-like products	extrusion panels	8	1965-1977	portland cement
	corrugated	20-45	1930-present	portland cement
	flat	40-50	1930-present	portland cement
	flexible	30-50	1930-present	portland cement
	flexible perforated	30-50	1930-present	portland cement
	laminated	35-50	1930-present	portland cement
	roof tiles	20-30	1930-present	portland cement
	clapboard	12-15	1944-1945	portland cement
	siding shingles	12-14	unknown-present	portland cement
	roofing shingles	20-32	unknown-present	portland cement
	pipe	20-15	1935-present	portland cement
Paper Products	corrugated: high temp.	90	1935-present	sodium silicate
	corrugated: moderate temp.	35-70	1910-present	starch
	indented	98	1935-present	cotton and organic binder
	millboard	80-85	1925-present	starch, lime, clay
Roofing felts	smooth surface	10-15	1910-present	asphalt
	mineral surface	10-15	1910-present	asphalt
	shingles	1	1971-1974	asphalt
	pipeline	10	1920-present	asphalt
Asbestos containing compounds	caulking putties	30	1930-present	linseed oil
	adhesive (cold applied)	5-25	1945-present	asphalt
	joint compound		1945-1975	asphalt
	roofing asphalt	5	unknown-present	asphalt
	mastics	5-25	1920-present	asphalt
	asphalt tile cement	13-25	1959-present	asphalt
	roof putty	10-25	unknown-present	asphalt
	plaster/stucco	2-10	unknown-present	portland cement
	spackles	3-5	1930-1975	starch, casein, synthetic resins
	sealanis fire water	50-55	1935-present	caster oil or polyisobutylene
	cement, insulation	20-100	1900-1973	clay
	cement, finishing	55	1920-1973	clay
	cement magnesia	15	1926-1950	magnesium carbonate
Flooring tile and Sheet Goods	vinyl asbestos tile	21	1950-present	poly(vinyl)chloride
	asphalt asbestos tile	26-33	1920-present	asphalt
	sheet good/resilient	30	1950-present	dry oils
Wallcovering	vinyl wallpaper	6-8	unknown-1973
Paints and Coatings	roof coating	4-7	1900-present	asphalt
	air tight	15	1940-present	asphalt