Home-immediately access 800+ free online publications. Download CD3WD (680 Megabytes) and distribute it to the 3rd World. CD3WD is a 3rd World Development private-sector initiative, mastered by Software Developer Alex Weir and hosted by GNUveau_Networks (From globally distributed organizations, to supercomputers, to a small home server, if it's Linux, we know it.)ar.cn.de.en.es.fr.id.it.ph.po.ru.sw

CLOSE THIS BOOKAsbestos Overview and Handling Recommendations (GTZ, 1996)
Part II. Asbestos
1. Introductory part: Asbestos - Deposits, uses, types, characteristics
VIEW THE DOCUMENT(introduction...)
VIEW THE DOCUMENT1.1 Types, deposits, and uses of Asbestos, chemical structure
VIEW THE DOCUMENT1.2 Mineralogical and mechanical properties of Asbestos
VIEW THE DOCUMENT1. 3 Analytical methods of determining Asbestos fibers
2. Legal regulations for the production, introduction to the market and use of Asbestos containing materials and Asbestos products
VIEW THE DOCUMENT(introduction...)
VIEW THE DOCUMENT2.1 Federal Republic of Germany
VIEW THE DOCUMENT2.2 Directives of the European Community
VIEW THE DOCUMENT2.3 United States of America
VIEW THE DOCUMENT2.4 Standards in other countries (incl. developing countries)
VIEW THE DOCUMENT2. 5 International standards: International Labor Organization
3. Environmental aspects and health hazards due to Asbestos
VIEW THE DOCUMENT3.1 Introduction
VIEW THE DOCUMENT3.2 Asbestosis
VIEW THE DOCUMENT3.3 Mesothelioma
VIEW THE DOCUMENT3.4 Other health hazards
VIEW THE DOCUMENT3.5 Risk determination
4. Application areas of Asbestos materials and Asbestos products
VIEW THE DOCUMENT4. 1 Introduction
VIEW THE DOCUMENT4.2 The meaning of composite fibrous materials
VIEW THE DOCUMENT4.3 Asbestos in the building construction area
5. Occupational safety measures in handling Asbestos
VIEW THE DOCUMENT(introduction...)
VIEW THE DOCUMENT5.1 Suitable fiber binding
VIEW THE DOCUMENT5.2 Wet operations
VIEW THE DOCUMENT5.3 Enclosure
VIEW THE DOCUMENT5.4 Vacuuming of dust near the point of origin
VIEW THE DOCUMENT5.5 Limiting the areas in which Asbestos dust may arise
VIEW THE DOCUMENT5.6 Personal respiratory protection
VIEW THE DOCUMENT5.7 Regular and thorough cleaning of workplaces
VIEW THE DOCUMENT5.8 Dust-free waste collection and landfill disposal
6 Aspects of Asbestos abatement and disposal of Asbestos containing materials
VIEW THE DOCUMENT(introduction...)
VIEW THE DOCUMENT6.1 Evaluation guidelines on the urgency of abatement
VIEW THE DOCUMENT6.2 Asbestos abatement techniques
VIEW THE DOCUMENT6.3 Disposal of Asbestos containing materials

Asbestos Overview and Handling Recommendations (GTZ, 1996)

Part II. Asbestos

1. Introductory part: Asbestos - Deposits, uses, types, characteristics

The different Asbestos minerals in the Earth's crust, their deposits and characteristics are presented in detail in this part. In particular, the minerals concerned are: chrysotile, amosite, crocidolite, anthophyllite, tremolite und actinolite, which are categorized on the basis of their chemical composition and fibrous structure as serpentine Asbestos (chrysotile) or amphibole Asbestos.

The following presents a classification of Asbestos minerals and a description of the chemical composition, physical properties and specific figures for Asbestos fibers. In addition, the important mines for the different Asbestos fibers are named.

1.1 Types, deposits, and uses of Asbestos, chemical structure

Asbestos is a collective term for a group of silicate fibers. The aforementioned six different Asbestos minerals can be categorized on the basis of their chemical composition (primary cation) and their crystalline and fibrous structure into the groups amphibole or serpentine Asbestos.

Serpentines have a leafy or layered structure. Amphiboles have a chain-like crystalline structure.


Figure 1: Classification of Asbestos Types


· Serpentine Asbestos:

Serpentine Asbestos (chrysotile, as most important type, and antigorite) is leaf structured and consists of fine fibers. The leaves consist of alternating layers of silicate tetrahedron (SiO4), which are held together by hydroxide groups (OH) and magnesium ions. The structure is similar to that of serpentine minerals.

Chrystolite Asbestos:

Chrysotile Asbestos fibers have a very small diameter, are tubular, very soft and bendable. The individual fibrilles have a diameter of 100 - 250 Angstrom (A). Chrysotile originates from the hydrothermal decomposition of ultra basic, primarily olivine-containing rock; particularly severe weathering occurs in subtropical and tropical climates.

Mines are located primarily in Ural (Bazenovo, Asbest, Dzetygara, Kiembaj), in Canada (Quebec, Ontario, British Columbia, New Foundland), as well as in South Africa (Zimbabwe, Botswana, South Africa).

Chrysotile, or white Asbestos, is the most widely used form of Asbestos. In the USA cat 95 % of all Asbestos types used in buildings is white Asbestos. Of the total German use of Asbestos, 96 % is chrysotile (1976).

· Amphibole:

Amphibole Asbestos types have a chain-like crystal structure, which stipulates their fibrous nature. Individual fibers have larger diameters, are straight, firm and hard, but elastic.

Amosite:

Amosite is a long-fibered Asbestos. Fiber length can reach 35 mm. Due to its needle-like structure it is a very dangerous type of Asbestos. On the basis of quantity (ca. 1% of all used types in Germany in 1976), amosite or brown Asbestos is second to only chrysotile as the most common form in buildings. It is primarily used in the manufacturing of light, fire-proof insulation sheets. The important mining areas are in South Africa.

Crocidolite:

The blue Asbestos is the most hazardous type of Asbestos and is primarily applied in pressure resistant pipes made of Asbestos cement. Economically, it is the most important type of amphibole (amphibole represented 3% of all Asbestos used in Germany in 1976, whereby > 90 % was from the manufacturing of pressure resistant Asbestos cement pipes). The diameter of fibers is very small: 0.1 - 0.2 mm; the surface of crocidolite consists of SiO4 - tetrahedrons. Important deposits are in South Africa and in West Australia.

· Mining:

The world production of Asbestos increased steadily until the early 1980's, since the economic value of the fibers stood in the foreground, although the risks of Asbestos have been known at least in part since cat 1930. The total world production of Asbestos peaked around 1976 at approximately 5.2 million tons (Mt). Currently the trend shows a steep decline (1986: 4.1 Mt, 1991: 3.5 Mt., US Bureau of Mines). The main producing and consuming countries were (see also the maps in Annex 1):

Table 1: Percentage of Asbestos Production among the Main Producing and Consuming Countries

Mining

(1976)

(1979)

(1987)

(1991)

Canada

(30 %)

(27 2 %)

(15.7 %)

(19.7 %)

USSR

(44 %)

(43.9 %)

(60.3 %)

(57.3 %)

South Africa

(12%)

(6.1 %)

(3.2 %)

(4.3 %)

Source: own compilation from different sources

Other important producing countries are currently: Brasil, Zimbabwe, China, Greece, India, Swaziland, Columbia and Japan. Meanwhile, the market shows a surplus of supply. The known worldwide supply of Asbestos ores will be sufficient to last far into the next century.

The largest part of Asbestos production is chrysotile (over 90 %), the remainder primarily crocidolite (ca. 4 %). The types amosite, anthopyllite, tremolite and actinolite are quantitatively (together < 2 %) of subordinate importance.

The annual tonnage, location and type of Asbestos at each mining site can be found in Tables 2 through 4 and the respective references.

Some of the most important Asbestos deposits are listed in Table 2.

Table 2: Asbestos Deposits

Country

Location

Asbestos Type

Rock Formation

References

USSR

S-Central Ural Sverdlosk, Tuva& Kustanay Region

C

US

Harben & Bates (1984)

Canada

Eastern Quebec

C

US

Lamarche & Riordon (1981)


N-E Quebec

C

US

Hanley (1987), Stewart (1981)


Newfoundland

C

US

Williams et al. (1977)


British Columbia

C&T

SP

Burgoyne (1986)

USA

N-Central

C

P&D

Chidester et al. (1978)


Vermont

C

SP

Mumpton & Thompson (1975)


California

C&T

AL

Harben & Bates (1984)


Arizona

An&C

U

Ross (1982), Puffer et al. (1980)


Georgia-Maryland New Jersey

C&T

AM

Germine & Puffer (1981)

Yugoslavia

Croatia

C

SP

Harben & Bates (1984)

Greece

Macedonia

C

H&I

Harben & Bates (1984

South Africa

Transvaal

C

AS

Dryer & Robinson (1981)


Transvaal

A&Cr

BI

Ross (1982)


Lyndenburg N-Cape Province

Cr

BI

Dryer & Robinson (1981)

Swaziland

Northern

Region

C

S&C Harben & Bates (1984)

Zimbabwe

Eastern Bulawayo

C

D&P

Harben & Bates (1984)

Australia

New South Wales

C

H&D

Butt (1981)

Finland

Karelian Mts.

An

US

Ross (1982)

Italy

Western Alps

C&T

S

Ross (1982)

China

Various Locations

C&T

U&Do

Hodgson (1986)

Brasil

Goias State

C

D&P

Beurian & Cassedanne (1981)

Asbestos Type

C = Chrysotile
T = Tremolite
An = Anthophyllite
A = Amosite
Cr = Crocidolite

Rock Formation

Se = Serpentine Rock
P = Periodotite
AS = Altered Sedimentaries
H&I = Harzburgite & Iherzolite
Do = Dolomite
AL = Altered Limestone
BI = Banded Ironstone
SP = Serpentinized Periodotite
D = Dunite
AM = Altered Marble
S&C = Altered Schist&Carbonates
US = Ultramafic Serpentinite
U = Ultramafic Rock

Source: Schreier, H.: Asbestos in the Natural Environment, Studies in Environmental Science, Amsterdam 1989

Table 3: Estimated Production Capacity of Asbestos Useable in Industry

Country

Asbestos (in Tons)

USSR

3.100.000

Canada

1.500.000

South Africa

400.000

China

300.000

Zimbabwe

300.000

Brasil

200.000

Italy

200.000

USA

120.000

Greece

100.000

Australia

100.000

Germany

90.000

Swasiland, Cyprus, India, Japan, Yugoslavia, Columbia, Turkey, etc.

> 50 000

(for each country)


Source: Schreier, H.: Asbestos in the Natural Environment, Studies in Environmental Science, Amsterdam 1989

· Processing:

In the western world 75% of Asbestos rock is produced in openpit mining with blasting, and in total 85% of the worldwide Asbestos rock is produced in this manner. Mining production refers to the amount of fiber gained from Asbestos mills. The mass content of fibers in rock lies around 3 - 10%. The crude rock is crushed in the mines with breaking and pan grinding operations and separated into fiber bundles. This is a largely mechanical process, which consists of many steps of screening and air sifting. These procedures are illustrated in Figure 2.

The conditions in the important Asbestos producing countries in Africa are markedly different. In Simbabwe and Swasiland Asbestos production is performed exclusively through deep mining, in the Republic of South Africa to 95% extent. Asbestos production in China is also 40% underground mining. In Canada the percentage of deep mining for Asbestos lies just above 5%, in the former USSR deep mining is not considered to play a significant role.


Figure 2: Illustration of Asbestos Mining Along a Slope and Dry Processing (Source: 1980)

· Further Processing Asbestos Cement

Asbestos cement is a fiber composite material made of primarily chrysotile Asbestos and cement and in some cases other additives, such as quartz, pigments, etc.. The first technical and economic procedures for manufacturing this construction material were developed by Hatscheck (1900).

Currently, even in the developing countries the large-scale technical procedures used are exclusively variations of that introduced by Hatschek, which is according to paper technology.

The manufacturing of Asbestos cement pipes according to Mazza and Mattei (1913) is also based in principle on the suggestions of Hatscheck.

In a continuous procedure, Asbestos, spread open to fine fibers, is mixed with cement and a great deal of water into a thin liquid suspension and then thickened to paper-like sheets as the excess process water is removed via felt cloth. Depending on the type of production, further manufacturing operations are performed with presses for sheets or with wrapping machines for pipes. (A detailed description of the historical and technological development of Asbestos cement is provided by Klos, 1967)

Table 4: Asbestos Percentages and Types in the Most Important Asbestos Cement Forms

Asbestos Cement Products

Asbestos content in matter wt -% relative to solid

Type of Asbestos

Supplements (outer Cement)

Standard sheets ( flat sheets for walls. roofs, etc., corrugated sheets for roofing) and pipeline fittings

9 -12

Chrysotile

none

Pressed pipes - sewer- and drainage pipes

12 - 15

Chrysotile (approx. 85%);
Crocidolite (approx. 15 %)

none

Light construction sheets (primarily for fire protection purposes)

15 - 30

Chrysotile; Amosite

Cellulose; Pearlite (Calcium silicate)

White sheets

6 - 9

Chrysotile

Quartz

Source: UBA - Report 1/80

· Consumption

In 1979, the countries with the highest consumption of Asbestos in percent of the total were:

Table 5:Asbestos Consumption ( 1979)

USSR

(31.7 %)

USA

(11.3 %)

Source: own compilation

From the maps in Annex [(with 1978-1981 data from the BGR/DIW study), it is apparent that the use of Asbestos materials primarily took place in the industrial nations. From this standpoint it can be argued that Asbestos is not a specific problem of the developing countries. Upon further analysis, however, it becomes clear that the present situation is different from that in 1981. Furthermore, in the study (BGR/DIW) no statements were made regarding how many Asbestos products are exported to the developing countries, leading to health risks there.

1.2 Mineralogical and mechanical properties of Asbestos

The majority of application areas for Asbestos result from the synthesis of different technical properties:

· high tensile strength
· resistance to moisture
· resistance to heat
· flexibility, elasticity
· cability of being spun
· flame retardant, fireproof
· insulation capacity
· good binding capability in many inorganic and organic binding materials
· chemical resistance (depending on Asbestos type, resistant against acids or bases)

The different Asbestos minerals demonstrate different characteristics influencing:

· potential application possibilities,
· the attractiveness of substances for multi-purposes,
· the resulting health hazards from the use.

In view of the above differences, there are different evaluation criteria among Asbestos minerals.

From a technological standpoint, chrysotile or white Asbestos demonstrates the most valuable characteristics, such as very high flexibility, fineness of fibers, capability of being spun, heat resistance, and alkali resistance. White Asbestos is therefore particularly important in addition to blue Asbestos (crocidolite) and amosite.

Table 6 shows an overview of figures for the most important types of Asbestos. More information can be found in the health and safety data sheet for Asbestos cement in the UK (Annex 2), and in an excerpt from the Compendium of Environmental Standards (KUSt, Katalog umweltrelevanter Standards), BMZ/GTZ (Annex 7).

1. 3 Analytical methods of determining Asbestos fibers

A number of techniques have been developed for the analytical determination of Asbestos fibers. The determination is generally performed in three steps: the sampling, fiber counting and determination of the type of fiber. These steps are presented below along with the most widely used determination procedures.

Sampling

For the determination of Asbestos in fluid media (air, water), a defined volume of the media is drawn through a filter, upon which the fibers are deposited. The typical filter materials are gold-coated track-etched membrane filters or cellulose membranes. In order to determine the number of fibers in solids (e.g. in material samples or in dust), the sample can be directly used.

Fiber Counting

Generally, microscopic techniques are applied for fiber counting. The optical counting of fibers proceeds in the simplest case under the phase contrast microscope. Since the optical resolution can at best include structures of 1 mm in size, whereas in airborne particulates the main fraction of fiber bundles has sizes ranging from 2 - 0.2 mm, phase contrast microscopy can at best be used as a screening method in cases of very high fiber concentrations (e.g. for the investigation of material samples). In the case of investigations of drinking water, phase contrast microscopy is totally unsuitable (sizes around 0.06 mm).

Sufficient resolution can be achieved with using scanning electrion microscopy (SEM) or with transmission electron microscopy (TEM). These procedures are relatively expensive, however, and require extensive measures in the preparation of the samples, in addition to well-educated operating personnel.

Asbestos fibers in particulate samples can also be determined on the basis of their characteristic absorption lines using infrared spectroscopy. However, the determination limit lies relatively high at 1-5%, depending on the type of fiber.

Table 6: Data on the Most Important Types of Asbestos


Serpentine

Amphibole


Chrysotile

Anthophyllit

Crocidolite

Actinolite

Tremolite

Amosite

Chemical formula

Mg3(OH)4Si2

(Mg,Fe2+)7

Na2(Fe2+,Mg)

(Ca,Na)2

Ca2(Mg,Fe)5

(Fe2+,Mg.Al)7


O5

(OH)2Si8O22

3Fe23+(OH)2

(Fe,Mg,Al)5

(OH,F)2Si8O22

(OH)2Si, Al)8




Si8O22

(OH, F)2


O22





(Si, Al)8O22



Chemical composition in (%)







SiO2

35 - 44

52 - 64

49 - 57

0 - 63

50 - 63

45 - 56

MgO

36 - 44

25 - 35

3 - 15

18 - 33

18 - 33

4 - 7

Al2O3, Iron oxide

0 - 9

1 - 10

20 - 40

2 - 17

2 - 17

31 - 46

CaO, Na2O

0 - 2

0 - 1

2 - 8

1 - 10

1 - 10

1 - 2

H2O

12 - 15

1 - 5

2 - 4

1 - 4

1 - 4

1 - 3

Physical properties

fine light fibers

prismatic crystal and fibers

long, brittle fibers

prismatic crystal and fibers

prismatic crystal and fibers

prismatic crystal and fibers

Color

white, grey, greenish

grey-white

blue

green

white, grey- white, greenish

ash grey

Texture

soft to rough, mostly silky

rough

soft to rough

rough

rough

rough

Flexibility

very high

low

good

low

low

good

Mohs-strenght

2,5 - 4

5,5 - 6

5,5 - 6

6

5,5 - 6

5,5 - 6

Fiber diamiter (nm)

18 - 30

60 - 90

50 - 90

0 - 90

60 - 90

60 - 90

Resistance (N/nm2)

210 - 560

< 28

280 - 420

7

7 - 56

70 - 140

Modulus of elasticity(N/nm²)

160.000

-

190.000

-

-

160.000

Melting point (C)

1.500

1.480

1.180

1.393

1.320

1.400

Specific heat (kj/kg C)

1,1

0,85

0,8

0,9

0,9

0,8

Surface (m²/g)

10 - 60

7

10



9

Thickness g/cm³

2,2 - 2,6

2,8 - 3,2

2,8 - 3,6

3,0 - 3,2

2,9 - 3,2

2,9 - 3,3

Breeking index







n (alpha)

> 1,53

> 1,59

> 1,68

> 1,61

> 1,60

> 1,64

n (gamma)

< 1,57

< 1,63

< 1,70

< 1,65

< 1,63

< 1,69

pH-Value

9,5 - 10,3

9,4

9,1

9,5

9,5

9,1

Electrical charge in aqueous suspension

+

-

-

-

-

-

Stable towards acids

unstable

very good

good

fairly good

good

good

Alkali resistant

very good

good

good

good

good

very good

capability of being spun

easily spinnable

barely spinnable

mostly spinnable

unspinnable

unspinnable

partially spinnable

Source: Umweltbundesamt (Publ.): Analysis of the Asbestos Industry, written by the Battelle-lnstitut Frankfurt e.V., Report 4/78, Berlin 1978

Determination of the Type of Fiber

The determination of the type of fiber and particularly the differentiation from other inorganic fibers can be directly performed under the transmission electron microscope using small angle electron diffraction (SAED). Another possibility is the energy dispersive X-ray analysis (EDXA). The arising diffraction or energy spectra are evaluated using numerical methods. The required infrastructure is relatively expensive and places high requirements on the operating personnel. The previously common use of phase contrast microscopy to determine the type of fiber in airborne particulates based on fiber geometry is unsuitable, due to low resolution.

The type of fiber can also be identified with infrared spectroscopy based on the characteristic absorption bands of chrysotile and amphibole types. This method is inexpensive, but only applicable if the fiber concentration in the sample exceeds about 1-5 percentage by weight.

In Germany there are two accredited American procedures for the measurment of Asbestos fiber concentrations. These VDI Guidelines are for fiber in particulates and in indoor air and replace the previously common phase contrast microscopy procedures:

VDI Guideline 3861

This guideline specifies a procedure for the determination of the fraction of Asbestos fibers in particulate mass, e.g. as they occur in air vents. The sampling proceeds through deposition of particulates onto a nitro-cellulose filter. This filter undergoes cold ashing, and the fiber concentration is then determined using infrared spectroscopy with the help of the KBr Pressure Technique. The analytical result is obtained as the weight fraction in g/kg.

VDI Guideline 3492

This guideline specifies a procedure for the determination of Asbestos fibers in indoor or outdoor air. The Asbestos fibers from a defined air volume are deposited onto a gold-coated track-etched membrane, which is then cold-ached, and subsequently the fibers are counted under the scanning electron microscope. The type of fiber is determined using energy dispersive X-ray analysis.

Due to the cost of this analytical procedure, it may be assumed that in developing countries at best the phase contrast microscopy and infrared techniques are available (cost of equipment < 50,000 DM). The electron microscopy procedures (costs >>100,000 DM) would currently be applied exclusively in industrial nations. Therefore, in developing countries it is questionable whether any existing limits, e.g. for indoor air concentrations, can be monitored.

2. Legal regulations for the production, introduction to the market and use of Asbestos containing materials and Asbestos products

For the hazardous substance Asbestos there are many legal regulations covering the different steps of production, introduction to the market and use of Asbestos containing products. Additionally, there are occupational safety regulations and legal specifications in context with the necessity of abatement of Asbestos containing areas and the disposal of Asbestos containing materials.

In this chapter the relevant laws, administrative rules, occupational safety requirements, operational safety requirements and other legal regulations are presented and discussed. Different industrial nations (Germany, USA), developing countries (DC) and supra-national agreements (KU, UNO [WHO and ILO]) are analyzed.

2.1 Federal Republic of Germany

In German federal environmental and health and safety law as well as in other areas, there are a number of regulations concerning Asbestos. In many sources, e.g. from Construction Law (State Construction Ordinances) to Occupational Safety Law, the Immission Protection Law (TA-Luft administrative rules) and Waste Law (TA-Abfall, LAGA-lnstruction Sheet "Disposal of Asbestos Containing Wastes"), there are rules and regulations on the manufacturing, introduction to the market, and use of Asbestos containing products. Additional extensive rules are also required by the Employers Association for Accident Insurance (Berufsgenossenschaft).

The following legislative works are of particular interest: The Hazardous Substance Ordinance and its related Technical Rule for Hazardous Substances (TRGS) 517 "Asbestos" and TRGS 519 "Asbestos- Remolval, Abatement or Maintenance Work", as well as the Asbestos Guideline (Guideline for the Evaluation and Remediation of Friable Asbestos Products in Buildings). The latter guideline will be discussed in Chapter 6.1.

Hazardous Substance Ordinance

The Hazardous Substance Ordinance (Gefahrstoffverordnug-GefStoffV) dated 26/08/1986, BGBI. I, currently valid in the version from 29/09/1994 (BGBI. 1.), regulates the introduction to the market of hazardous substances, the handling, storage and destruction of hazardous substances. The ordinance is based on the Chemical Law (Chemikaliengesetz).

In the Second Amendment to the Hazardous Substance Ordinance on 23 April 1990, the regulations concerning the handling of Asbestos were significantly tightened. The manufacturing and use of Asbestos containing hazardous substances became prohibited, however this refers only to the materials explicitly listed in Annex 11 under 1.3.1.2, which include the most important light Asbestos cement sheets (unit weight < 1.0 g/cm³), coating substances, substances or preparations for spraying or trowelling as well as insulation materials for fire, sound or heat protection and floor and street coverings. Furthermore, all crocidolite containing substances are listed.

A prohibition for manufacturing refers to fiber-reinforced thermoplast masses.

A central regulation of the Hazardous Substance Ordinance is the Substitution Order, whereby the applied amounts of Asbestos are to be limited as far as possible and the possibility of using nonhazardous substitutes is to be examined. In support of the Substitution Order, the authorities have the option to forbid the use of carcinogenic products.

The Hazardous Substance Ordinance is the central regulatory element in Germany for the handling of and protection against hazardous substances. In 1986 it replaced the Working Medium Ordinance including another 35 relevant ordinances and incorporated 14 EU-Guidelines into national law. The EU-Guideline on Asbestos referred to under 2.2 was also included.

In January 1995 a general prohibition ordinance for the manufacturing, introduction to the market and use of Asbestos containing materials came into effect. The same exceptions and interim deadlines are foreseen that were in the Hazardous Substance Ordinance. A new rule is the prohibition of working on Asbestos cement products (which were permitted to be manufactured until the end of 1993) in a manner which could destroy the surface. The production and use of sprayed Asbestos has been forbidden since 1979.

Further requirements on occupational safety in handling Asbestos are:

Technical Rules of the Board for Hazardous Substances at the Federal Ministry for Work and Social Order:

Technical Rules on Hazardous Substances (Technische Regel Gefahrstoffe) TRGS 517 "Asbestos"

Technical Rules on Hazardous Substances TRGS 519
"Asbestos - Removal, Abatement or Maintenance Work"

The technical guideline concentration (technische Richtkonzentration, TRK) in the workplace air is specified in the TRGS 102, and for chrysotile Asbestos it is 250,000 Fibers per m³ air (as of 1990 after adjusting to the Second Change of the Hazardous Substance Ordinance). As of the newest version of the TRGS 102 in January 1994, there is no longer a TRK value for Asbestos fibers in work involving Asbestos removal, abatement and maintenance, which means that in these work areas the full spectrum of measures according to the TRGS 519 must be followed. For amphibole Asbestos, there was not a TRK value in 1993, since its use had already been prohibited.


Table 7 Exposition Limits for Asbestos Fibers According to German Occupational Law


MAK-Value

TRK-Value

Asbestos containing fine particles:

6 mg/m³ 1)

-

Chrysotile:

6 mg/m³ 1)

250,000 F/m³

Amosite

6 mg/m³ 1)

_2)

Anthophyllite

6 mg/m³ 1)

_2)

Actinolite

6 mg/m³ 1)

_2)

Tremolite

6 mg/m³ 1)

_2)

Crocidolite

6 mg/m³ 1)

_2)

1) general limit for particulates
2) the latest TRGS no longer has a limit for this, since the substance is not allowed to be used anymore

Source: own compilation

Measurements of Asbestos fiber concentrations are to be performed according to ZH1/120.31. In plans for abatement, a maximum value of 50,000 fibers per m³ air is given. The TRGS 100 defines the limits for hazardous substances above which additional measures must be undertaken. The TRgA 124 (Technical Rules for Hazardous Working Substances, Technische Regeln fr gefhrliche Arbeitstoffe) defines the limit for Asbestos.

Technical Rules for Hazardous Working Substances TRgA 601
"Substitutes for Asbestos"

Technical Rules for Hazardous Working Substances TRgA 402
"Measurement and Determination of the Concentrations of Hazardous Working Substances in the Air; Application of the Maximal Workplace Concentrations (MAK) "

In addition, there is an extensive regulatory work from the Employers' Association for Accident Insurance (Berufsgenossenschaften BG) in the form of rules on accident prevention and safety measures. There are also regulations on identifying Asbestos (ZH 1/120.30), on lung-endangering fibers (ZH 1/120.31), and guidelines for the evaluation and abatement of friable Asbestos products in buildings (Asbest-Richtlinien, in the version from January 1990), which will be discussed further in Chapter 6.2 of this part.

2.2 Directives of the European Community

In 1983 the Commission of the European Community enacted the Council Directive on the protection of workers from the risks related to exposure to Asbestos at work (83/477/EEC). This directive is based on the 1980 Council Directive on the protection of workers from the risks related to exposure to chemical, physical and biological agents at work (801 1107/EEC, EC-Agents Guideline) It contains the minimum requirements for the protection of workers from Asbestos containing hazardous materials, comparable to the TRK values in Germany.

The rules of this guideline are applicable to workplaces with a concentration of more than 0.25 fibers per cm³ air and/or a cumulative dosis of more than 15 fiber-days per cm³ air over a period of 3 months.

For this type of classified areas the following regulations apply, among others:

a) prohibition of working with Asbestos by means of spraying;

b) a limit for Asbestos fibers, except for crocidolite, of 1.0 fibers per cm³ air measured or calculated for an 8 hour reference period;

c) a limit for crocidolite of 0.5 fibers per cm³ air measured or calculated for an 8 hour
reference period;

d) for mixed Asbestos fibers a limit from b) and c) according to the ratio of crocidolite to
other Asbestos fibers;

e) a distinct labelling using relevant warning symbols,

f) prohibition of smoking.

These limits apply only for Asbestos fibers with a length/diameter ratio of 3: 1.

Where the above limits are exceeded, appropriate measures to reduce Asbestos emissions must be performed, or if that is not possible, appropriate protective clothing and respiratory protection must be worn.

The guideline also contains general duties for employers (e.g. investigational duty, supervision duty, order to minimize the concentration of Asbestos in the air, duty to submit notification of the manufacturing and use of Asbestos containing materials).

Another EU-Guideline governs the labelling of Asbestos containing preparations and products. In 1983, the "a" for the labelling and the formulation "Achtung, enthlt Asbest! Gesundheitsgefahrdung beim Einatmen von Asbeststaub" ("Warning, contains Asbestos! Inhalation of Asbestos particles is hazardous to health" was incorporated into the general European Law to protect against potential health hazards. This Guideline (83/478/ EEC) represented a change to the Guideline 761769/EEC. The same applies to the Guideline 85/610/EEC, which more strictly limited the introduction to market and the use of Asbestos containing substances and preparations in 1985. Further changes followed. The latest change in the guideline dated 3 December 1991 (91/659/EEC) prohibits production and use of Asbestos containing materials in many areas of application, and in some instances intermediate provisions are stipulated.

2.3 United States of America

The Asbestos regulations in the USA are primarily determined by the two federal authorities "Environmental Protection Agency (EPA)" and "Occupational Safety and Health Administration (OSHA) ". The EPA is the federal environmental authority, OSHA determines formulations and implementation of occupational measures.

· EPA

The regulations of EPA are related to:

· use and removal of ACM (Asbestos containing material) in new buildings or during renovation of buildings;

· identification of Asbestos in public buildings (schools) and control of fiber emissions;

· industrial Asbestos fiber emissions.

The first regulations of the EPA on Asbestos date from 1973. They were in the frame of the NESHAP-Program (National Emission Standards for Hazardous Air Pollutants), which directly addressed the Asbestos processing industry and prohibited the use of sprayed Asbestos in new buildings. Furthermore, measures in handling Asbestos during abatement/removal plans were formulated. This legislation was appended and modified several times (1975,1978, 1990). Today the use of sprayed Asbestos in connection with renovation and constructional modifications is forbidden; additionally, there are rules and limits for the disposal of Asbestos containing materials.

The second legal regulation of the EPA falls under the "Toxic Substances Control Act (TSCA)", which can be compared to the (German) Hazardous Substance Ordinance and is the main legal reference source for the control of Asbestos in the USA. The Rule 40 CFR, Part 763 or AHERA 1987, "Final rules and notice (Friable Asbestos Containing Materials in School)" referred to Asbestos in schools and consequently established very strict rules. This Rule included, in particular, the regular supervision and analysis of friable Asbestos fibers, documentation of all suspected cases and the results, and information of the affected public.

The maximum allowable Asbestos fiber concentration in the air according to the AHERA-Rule is dependent on the size of the critical area:

(1) In an area with less than 160 ft² or with a length less than 260 ft, the limit is 0.01 F/cm³ (F=Fibers). The analysis is to be performed according to NIOSH 7400. At least 5 samples must be analyzed.

(2) The documentation of a successful abatement by removing Asbestos containing materials is performed in 3 steps: visual inspection; new sampling of the air in the problem area and outdoors; and microscopic determination of fiber concentrations.

· OSHA

The OSHA-Laws apply to occupational safety in all work places which have contact with hazardous substances. Hence, they also apply to Asbestos. Their application is limited to only the industrial area. The goal of the formulation of the OSHA-rules on Asbestos was health protection, particularly against the already known risks Asbestosis, mesotholioma and cancer, primarily due to inhalation of Asbestos fibers into the lungs.

The first regulations under OSHA were implemented in 1972 and were modified in 1976 and 1986. They specified limits for fiber concentrations in the air at workplaces for the employees in the Asbestos industry, in addition to control mechanisms, medical exams (preventive care), workplace practices and necessary protective clothing for workers.

OSHA refers to the so-called TWA (= time weighted average), meaning that the allowable concentrations depend on the period of exposure. Different time periods were referenced in the legislature, whereby the 8-hour cycle is the most important, since it matches the length of shifts.

The most important rules and limits are as follows:

(1) PEL = permissible exposure limit

0.2 F/cm³ for a weighted average over 8 hours

This value of 0.2 F/cm³ for a fiber length of > 5 ym was fixed in 1986 by the amendment 29 CFR 1926.58 and represents a significant reduction of the former limits.

(2) Above 0.1 F/cm³ for a weighted average over 8 hours there are specific health and safety measures to be undertaken.

These include primarily particular protective clothing, but also obligatory instructions and training measures as well as medical exams.

A summary of the development in the U.S. federal legislation on Asbestos is presented in Annex 4.

2.4 Standards in other countries (incl. developing countries)

Table 8 shows an overview of the international standards for Asbestos limits. They have been taken from the "code of practice" of the International Labor Organization (ILO) on "Safety in the use of Asbestos" from 1984, and refer to the situation up to 1983.

The table describes only the state of the legislation in 1983, which certainly limits the application for the current situation. For instance, in the USA the limits are no longer checked, but rather a ban on Asbestos and Asbestos containing products has been discussed for all types of Asbestos applications with a deadline of 1996, and for some particular ones a deadline of 1993 has been fixed.

With regard to the table, it is apparent that between industrial, verging and developing countries there are no large differences in the legislation concerning maximum Asbestos exposure. However, based on these data, a qualitative statement cannot be made on the actual situation nor on the implementation of the legislation. Furthermore, only a few developing countries are explicitly listed in the table.

Table 8: International Regulations on Asbestos

Country

Regulations

Limit values (f = fiber)

Australia

National Health and Medical Research Council

Amosite 1.0 f/ml



Chrysotile 1.0 f/ml



Crocidolite 0.1 f/ml

Austria

July 1980

1,250 particles/cm³ (dust cont. < 2,5 % Asbestos)



650 particles/cm³ (dust cont. 2,5-15 % Asbestos)



300 particles/cm³ (dust cont. 15-50 % Asbestos)



150 particles/cm³ (dust cont. > 50% Asbestos)

Belgium

January 1980

Amosite 2.0 f/ml



Chrysotile 2.0 f/ml



Crocidolite 0.2 f/ml

Canada

Special regulation in each province

1982 Ontario:



Amosite 0.5 f/ml



Chrysotile 1.0 f/ml



Crocidolite 0.2 f/ml



other provinces including Quebec still have a time



weighted average (TWA) of "less or equal" to 2.0



f/ml for Asbestos in general

Cyprus

Amendment 1981, No. 1705

All types of Asbestos 2.0f/ml

Czechoslovakia

Ministry of Health, Czechoslovak Socialist Republic, Guidelines No. 46, 1 I May 1978

Dust containing Asbestos



(a) below 10 %: 4 mg/m³



(b) over 10 %: 2 mg/m³

Denmark


Crocidolite 0.1 f/ml



All other types of Asbestos 2.0 f/ml

Finland

23 September 1976

All types of Asbestos 2.0 f/ml

France

Decree No. 77-949, 17 September 1977

All types of Asbestos 2.0 f/ml

Fed Republic of Germany

1 July 1982

All types of Asbestos 1.0 f/ml

India

Model Rule 123-A under section 112 of the Factories Act

Amosite 2.0 f/ml



Chrysotile 2.0 f/ml



Crocidolite 0.2 f/ml



Other forms 2.0 f/ml

Indonesia


Amosite 1.0 f/ml



Chrysotile 1.0 f/ml



All other types of Asbestos 4.0 f/ml;



no standard given for Crocidolite, which is



understood to be banned

Ireland

1972, 1975

Amosite 2.0 f/ml



Chrysotile 2.0 f/ml



Crocidolite 0.2 f/ml

Israel

Jan. 1980, March 1982

All types of Asbestos 1.0 f/ml

Italy

All types of Asbestos 1.0 f/ml


Japan

Japan Industrial Health Society 1981

Crocidolite 0.2 f/ml



All other types of Asbestos 2.0 f/ml

Netherlands

October 1983

Chrysotile 2.0 f/ml



Crocidolite forbidden

New Zealand

24 August 1981

Actinolite, Amosite, Anthophyilite, Chrysotile,



Tremolite:



(a) 1.0 f/ml for any 4 hours' exposure



(b) 6.0 f/ml for any 10 minutes' exposure



Crocidolite: 0.2 f/ml for any 10 minutes' exposure

Nigeria

Draft Code of Practice

All types of Asbestos 2.0 f/ml

Norway

May 1983

Amosite 0.5 f/ml



Tremolite 0.5 f/ml



Crocidolite 0.2 f/ml



All other types of Asbestos 2.0 f/ml

Spain

August 1982

All types of Asbestos 2.0 f/ml

Sweden


All types of Asbestos (except corcidolite) 1.0 f/ml

Thailand

30 May 1977

All types of Asbestos 5.0 f/ml

United Kingdom

1 January 1984

As from I August 1984:



Amosite 0.2 f/ml



Chrysotile 0.5 f/ml



Crocidolite 0.2 f/ml

United States

1 July 1976, OSHA

All types of Asbestos 2.0 f/ml (currently under revision) threshold limit values (TLV's) recommended by ACGIH (American Conference of Governmental



Industrial Hygienists), 1982:



Amosite 0.5 f/ml



Chrysotile 0.5 f/ml



Tremolite 0.5 f/ml



Crocidolite 0.2 f/ml



all other forms of Asbestos 2.0 f/ml

USSR

GOST, 12-1-005-76

Dust containing over 10 % Asbestos: 2 mg/m³



Asbestos cement: 6 mg/m³



Asbestos bakelite: 8 mg/m³

Zambia

1 January 1984

Amosite 0.2 f/ml



Chrysotile 0.5 f/ml



Crocidolite 0.2 f/ml (is not imported into Zambia)



All other types of Asbestos 1.0 f/ml

Quelle: ILO: Safety in the use of Asbestos, 1984

2. 5 International standards: International Labor Organization

The ILO was founded in 1919, as a forum for the development of common measures for governments, employers and unions to support social fairness and to improve living conditions throughout the world. In 1946 the ILO became the first special organization in the United Nations. Today the ILO has 149 member nations.

One of the most important duties of the ILO is the working out of agreements and recommendations for the improvement of working conditions. Agreements and recommendations specify minimum requirements and provide examples and suggestions for the international law of the member nations. With the ratification of an agreement, the member nations are obliged to apply the stipulations of the agreement and to submit themselves to international controls. A recommendation is comparable to an agreement, does not require ratification and contains detailed guidelines.

The ILO published the Code of Practice on Safety in the Use of Asbestos in 1984. These guidelines include recommendations on the following matters, among others:

- Responsibility of employers and employees in the Asbestos processing industry,
- Asbestos investigations at workplaces,
- Use of alternative materials,
- Occupational safety measures and training,
- Packaging, transport and storage of Asbestos containing products,
- Disposal of Asbestos containing wastes and
- Information on the labelling of Asbestos containing products.

The guidelines do not contain exposure limits.

Further, measures to reduce Asbestos exposure are recommended, particularly for Asbestos mining and the processing of Asbestos containing textiles, cement, insulation, clutches and break linings.

Based on these recommendations, an agreement on Asbestos was passed in 1986, and has since been ratified by Canada, Finland, and 9 other member nations (see Table 9).

Table 9: Asbestos Convention, 1986 (Date of entry into force: 16/06/1989)

States

Ratification registered

States registered

Ratification

BOLIVIA

11.06.90

GUATEMALA

18.04.89

BRAZIL

18.05.90

NORWAY

04.02.92

CAMEROON

20.02.89

SPAIN

02.08.90

CANADA

16.06.88

SWEDEN

02.09.87

ECUADOR

1 1.04.90

UGANDA

27.03.90

FINLAND

20.06.88



Total ratifications: 11

Source: ILO

The agreement on Asbestos was appended by the "Recommendation on Safety in the Use of Asbestos" in June 1986.

3. Environmental aspects and health hazards due to Asbestos

3.1 Introduction

In the discussions on environmental aspects and health hazards of Asbestos, the focal point is particulate generation (fiber emissions) and inhalation of fibers. Other process-caused environmental impacts (e.g. production wastewater, energy consumption, etc.) from the further processing of Asbestos to marketable products are not mentioned here.

The environmental hazards of Asbestos are primarily in the form of health impairments. The carcinogenic effect of asbests from inhalation of microfibers has been scientifically confirmed in many studies. Asbestos is classified as particularly carcinogenic in the Hazard Group I of the German Hazardous Substance Ordinance (chrysotile at a mass content 2 than 2%, amphibole Asbestos 2 0.5%. Additionally, there are confirmed results on the so-called fibrogenic effect of Asbestos, by which scar tissue forms as a result of Asbestos inhalation. As a consequence, functional tissue of the lungs is destroyed and connective tissue increases.

3.2 Asbestosis

The hazard of Asbestos is due to the size and shape of the fibers. The prerequisite for damage to humans is the occurance of Asbestos particulates which can enter the lungs. Such fibers have aerodynamic diameters at or below 7 micrometers, whereby the aerodynamic diameter is about 3 times larger than the actual diameter (IACS). The resulting health damaging effect has been recorded since the beginning of this century. ln 1927, the term "Asbestosis" was assigned to the symptoms of a lung disease, and referred to the chronic lung disease with a change in the lung tissue due to the fibrogenic effect of Asbestos. Asbestosis ends frequently with lung cancer, in which case Asbestos is the promoter or co-carcinogenic agent.

In 1955, the significant link between Asbestos exposure and lung cancer was first confirmed scientifically. Another Asbestos-caused form of cancer, the mesothelioma of the pleura and peritoneum, has been researched since 1960.

In the Federal Republic of Germany the described diseases were recognized as occupational sicknesses (1936: Asbestosis; 1943: Asbestosis in combination with lung cancer, 1970: mesothelioma of pleura and peritoneum).

Asbestosis has been known of and observed the longest. Its occurance is linked to the exposure of high fiber concentrations; the exposure period is extends from years to decades. The average latent time of Asbestos-caused lung cancer is considered to be 25 years. However, it must be considered that different factors can influence the outbreak of the disease. For instance, the danger of acquiring Asbestosis increases by a factor of 53, if in addition to Asbestos exposure the risk factor of smoking is present, since the main human protection mechanisms, e.g. the mucuciliar transport of fibers by the cilia, are not functional or at least strongly impaired. (IACS)

3.3 Mesothelioma

Mesothelioma of the lining of the pleura and peritoneum is one of the most malignant forms of cancer. The occurance is relatively seldom and stands in direct correlation with occupational exposure to Asbestos. From previous studies it is known that at least 70 % of the known cases were due to occupation. Characteristically, there is an extremely long latent period of up to 50 years; in general about 25 - 35 years is found and the minimum latent period is 20 years.

3.4 Other health hazards

The above named diseases can be considered the "classical" Asbestos-caused diseases. The cause-effect relationship has been confirmed. In contrast, there is not complete epidemiological verification of this relationship for other diseases (malignant tumors e.g. of the urinary bladder, the gastrointestinal tract, the larynx, the esophagus), whose causes are traced to Asbestos handling. Due to the complexity of the cause-effect relationships and the multitude of other possible influences, a selective causal relationship between Asbestos exposure and the listed diseases is very hard to methodically prove.

Oral intake of Asbestos fibers is considered by some researchers to be another health risk. An existing Asbestos contamination of drinking water from geogenic background contamination can be differentiated from that due to Asbestos containing cement pipes. Asbestos cement pipes have been used for drinking water conduits and for wastewater sewers for over 100 years. They contain about 10-15 wt.-% Asbestos fibers, usually chrysotile. The possibility that Asbestos fibers will be released and enter the drinking water is given through mechanical and chemical wear. For instance, the layers can be damaged through the grinding effect of sand. In 1974 the American Water Work Association investigated the danger of fiber release from intact pipe connections and could not find any evidence for this. However, in old pipes (> 30 a), particularly unlayered pipes, and/or as a consequence of a pipe burst (e.g. due to frost), continual or periodic releases of Asbestos fibers can occur. An elevated Asbestos fiber release rate is particularly expected with the presence of chemically aggressive water. It has been proven that the binding of hardened Asbestos cement can chemically react with different liquids and gases (for example with NH4+ and Mg-salts, high sulfate-concentrations, humine acids, carbonic acid, etc.). The strength of the cement matrix can be reduced through the reactions, and the binding impaired or partly destroyed by the dissolution of individual components. As a consequence, a significantly higher amount of Asbestos fibers can be released. To prevent this process, it is recommended to exactly determine the drinking water chemistry with respect to pH and carbonate saturation.

International literature on oral intake of Asbestos fibers via the gastrointestinal tract and the resulting effects has grown to nearly 200 works (Martels/Schormann, in Asbest-Handbuch, No. 4570, Asbest im Trinkwasser und ihre Bewertung (Asbestos in Drinking water and ids Evaluation)). Epidemiological studies on the effects of oral intake of Asbestos fibers have been performed in different countries, in particular Canada and the U.S.A., without being able to prove significant relationships to increased cancer cases or increased mortality, although in some cases very high Asbestos fiber values in drinking water were present (up to several million fibers per liter) (UBA-Reports 5/91). These investigations can be distinguished as follows:

· Asbestos contamination through natural sources
(Quebec-Study, San Francisco-Bay-Studies, Puget-Sound-Study)

· Contamination by Asbestos mining (Duluth-Studies)

· Contamination of drinking water by Asbestos water pipes
(Utah-Study, Connecticut-Studies, Florida-Study)

Only the San Francisco-Bay-Studies (Kanarek, Conforti et al.) provide through the results of linear regression analyses indications of a causal relationship between cancer of the gastrointestinal tract and the oral intake of Asbestos fibers through water, food and beverages. However, since these results are overlaid with a number of other factors, the explanation of the factor "oral intake of Asbestos fibers" for the cancer arisings is doubted by a number of scientists.

In the Federal Republic of Germany the measured Asbestos fiber concentrations in drinking water range from < 5,000 up to 60,000 fibers per liter (UBA-Report 5/91). However, it should be noted that these fiber concentrations cannot be viewed as representative for Germany, since they are the result of 38 samples.

Numerous investigations confirm that the Asbestos concentrations in drinking water vary greatly from that in the air. They are generally much thinner and shorter than in the air (median values for the fiber length are between 0.5 ym and 0.8 km in water, the diameter lies between about 0.03 ym and 0.08 ym). The amount of fibers potentially released from the water into the air (e.g. by showering, cleaning, etc.) is largely agreed by all researchers to be classified as relatively unhazardous to the health. Research performed in the U.S.A., however, shows that with very heavily Asbestos-contaminated drinking water (fiber concentrations between 10(6) and 10(13) FA), fiber concentrations in the surrounding air inside houses were found up to 52,000 F/m³ (in comparison: in residential buildings with low Asbestos-containing water only 7,600 Faser/m³),. and the outdoor air of these very heavily contaminated houses showed values of up to 20,000 F/m³. Within buildings peak values of up to 240,000 F/m³ (during vacuuming) were measured.

With regard to the arising health hazard, it should be pointed out that due to the shorter fibers, the danger of intake through inhalation is decreased. (Usually fibers had lengths < 0.5 km; the average fiber length was FL = 0.61 ym; for comparison: in the few less contaminated residences FL = 0.81 ym). Nevertheless, with the optimistic assumption of just 2 % of the fibers having a length > 5 ym, a contamination of cat 1,000 F/m³ is calculated, which represents the tolerable value for a lifelong contamination as defined by the German Federal Health Agency (Bundesgesundheitsamt).

3.5 Risk determination

There is no way to directly measure the health risks, in particular the cancer risk, caused by Asbestos fiber concentrations in the environment. A risk quantification is only statistically possible through evaluation of sickness data or mortality numbers of persons occupationally subjected to Asbestos. Based on relationship known for over 50 years, there have been longterm investigations on this question, in Germany particularly through the Employers Associations for Accident Insurance (Berufsgenossenschaflen). Usually, however, direct measurement of Asbestos concentrations at the workplace is no longer possible, since due to the relatively long latent period, the past working conditions can only be approximately reconstrued. Through such experiments, the Asbestos fiber concentrations can only be estimated, and particular experimental conversion factors are scientifically applied. Additionally, a number of other factors play a significant role in this relationship, as described.

The investigations indicate that the Asbestos concentrations in the workplace in the '30s and '40s were a factor of 3-4 higher than the typically found Asbestos concentrations today, which originate primarily from old Asbestos contaminations. The emission from Asbestos processing has been greatly reduced, due to the strict legal regulations and the resulting limitations or prohibitions in use.

Table 10 presents the results of measurements of the ambient concentration of critical Asbestos fibers (> 5 ym in length, < 3 ym in diameter and ratio of length to diameter > 3:1 ) in Germany during 1984 and 1989. Table 11 provides further results of outdoor air measurements of Asbestos.

Table 10: Asbestos Fiber Concentrations

Concentration (F/m³)


50 - 140

in the area of use of Asbestos cement corrugated sheets

50 - 150

in urban areas, including those noted with elevated traffic density

80 - 350

in the area of factories processing Asbestos fibers

Source: Central Employers Association for Accident Insurance (Hauptverband der Gewerblichen Berufsgenossenschaflen), St. Augustin, Germany

The range of Asbestos fiber concentrations resulting from various activities is evident in Table 10. Asbestos cement products which were used outdoors, typically as roofing or as facade sheets, are considered to be relatively low health risks, as are indoor wall and ceiling coverings made of Asbestos, given the following limiting conditions: no mechanical processing occurs; the Asbestos is firmly bound in a cement matrix; and the binding in the matrix has not been impaired by age or mechanical wear. For outdoor air, Asbestos cement sheets on roofs and facades currently represent the most important emission source in Germany. This can vary from country to country, however. For instance, products of friction (especially Asbestos containing brake linings) in urban areas with elevated traffic in countries which have not prohibited such brakes, can lead to high fiber releases. This is apparent from the Table 11.

Table 11: Asbestos Fiber Concentrations

Fiber Concentration (F/m³)

Areas

< 100

rural areas

100 - 200

urban areas

100 - > 300

immediate vicinity of Asbestos emitters

to > 20 Million

exhaust from Asbestos containing car breaks with compressed air or from abrasive cutting of Asbestos containing materials

to > 500 000

roofing as well as drilling work on Asbestos cement

occasionally > 20.000

indoor air: in areas of sprayed Asbestos (depending on the condition of the material's surface)

Source: UBA-Report 5/91 - changed

The health risk due to Asbestos fiber concentrations can only be quantified on the basis of case numbers. As shown in Table 12, nearly 70% of the compensated occupational illnesses in Germany between 1978 and 1986 were caused by Asbestos. Therefore, Asbestos is the primary carcinogen in the workplace. It should be noted that due to the long latent period, an increase in the reported occupational illnesses caused by Asbestos may be expected in the future. This holds for both Asbestos-caused lung and larynx cancer as well as for mesothelioma.

Table 12: Occupational Illnesses for which Compensation has been Paid in the Federal Republic of Germany during the Period of 1978 - 1986

Cause

Number of Cases


no.

%

Asbestos

1,021

68. 5

aromatic amines

149

10.0

quartz

66

4.4

pitch, tar, tar oil

54

3.6

benzine

38

2.5

chromates

38

2 5

uranium. decay products

28

1.9

oak and beach wood dust

22

1.5

halogenated hydrocarbons

20

1.3

arsenic and compounds

16

1.1

halogenated ether

12

0.8

others

29

1.8

Total

1,491

100

Source: Central Employers Association for Accident Insurance (Hauptverband der Gewerblichen Berufsgenossenschaften), St. Augustin, Germany

Table 13: Mortality Risk of Various Activities and Occurances


Individual Risik per Year

Average Risk per 1,000 Persons/Year

automobile accidents

2.2 E - 04

0.22

fire and explosions

3.7 E - 05

0.037

30 mrem radiation exposure

1.5 E - 05

0.015

accidents in the home

1.2 E - 05

0.012

therapeutical, medical or surgical treatment

6.3 E - 06

0.0063

electrical shock

5.0 E - 06

0.005

1000 Asbestos fibers/m³ (Mesotheliom)

1.2 E - 06

0.0012

struck by lightning

4.4 E - 07

0.00044

bites and stings (from poisoness animals)

1.2 E - 07

0.00012

Source: Umweltbundesamt (Publ): Asbestos - Construction Material, Health Risks, Report 5/91 of the UBA, Berlin 1991

Table 13 compares the mortality risk associated with mesothelioma caused by Asbestos fiber inhalation with other risk factors.

In general, the risk of becoming ill from Asbestos depends on the following factors:

· age during exposure,
· length of exposure,
· fiber concentration,
· type of Asbestos.

It is not possible to define limits below which health risks can be entirely excluded. For this reason, the goal is always to achieve a minimal Asbestos fiber exposure. New research in the U.S.A. particularly emphasizes the health hazards from amphibole Asbestos and pleads for a general prohibition of this type of Asbestos.

In summary, the following has been determined:

· The health risk from the inhalation of Asbestos fibers which can reach the lungs is
generally considered critical and is undisputed worldwide, with few exceptions. The
actual health hazard depends on further factors (type of Asbestos, exposure length, fiber
concentration, age during exposure, other stimuli (e.g. smoking), etc.).

· The health risk of oral intake of Asbestos fibers from Asbestos contaminated drinking
water has not been as well researched and is currently the focus of further studies. Past
investigations have reached different interpretations.

· According to the current research findings, a release of Asbestos fibers from liquid
media (drinking water, beverages) into the surrounding air is only regarded as potentially
critical to the health for extremely high fiber concentrations in the liquid (>> I million
fibers/liter).

· For industrial uses of water with high Asbestos fiber concentrations, particularly in
industrial cleaning processes, there is a danger of high Asbestos concentrations in the
outdoor air. This area has not been researched very much.

4. Application areas of Asbestos materials and Asbestos products

4. 1 Introduction

Due to the material properties of Asbestos, there are a large number of application areas. Asbestos is an excellent insulation and binding material and a component of numerous building materials. The start of industrial use of Asbestos dates back to the last century. The number of marketable Asbestos products is estimated as several thousand. (see IACS, p. 1.1)

The most important application areas for Asbestos were:

· surface materials

· prefabricated products for heat insulation

· textiles

· cement type products for building construction (Asbestos cements): cement pipes (also in drinking water supply facilities) and cement sheets

· paper products

· roofing materials

· tiles

· wall paneling

· paints/coatings

· friction products (brakes, clutches)

· pipe wrap made of sprayed Asbestos

· membrane and filter technologies, separators, gaskets

4.2 The meaning of composite fibrous materials

The main application area of Asbestos is currently in the area of composite fibrous materials. These are materials in which fibers are bedded in an unorganized form in a continual matrix of a second material. Such composite materials combine the mechanical properties of fibers, such as the high tensile strength, in an ideal way with the properties of the matrix (anisotropic properties, pressure resistance, easy manufacturing). The basic prerequisite for the manufacturing of a composite fibrous material is a good bonding between the individual fibers and the material of the continual matrix, so that the tension in the material is conveyed to the fibers, thereby ensuring that their mechanical properties are usable.

The great advantage of Asbestos is that it occurs in nature in fine fibers and does not have to be manufactured in extensive processes - such as in the case of glass fibers. Furthermore, Asbestos fibers adhere well to cement, so that there is a conveyance of the tensions in Asbestos cement to the fibrous portion. These properties, as well as the high thermal stability, the electrical properties and the low price, have led to a wide spread of Asbestos containing materials and insulation materials in the building construction area.

4.3 Asbestos in the building construction area

The quantitatively most important use of Asbestos is without a doubt in building construction materials. There it is differentiated between tightly bound Asbestos (nonfriable Asbestos) and weakly bound Asbestos (friable Asbestos). In Asbestos cement products, Asbestos is tightly bound by cement, and the Asbestos fraction is generally < 15 %). In sprayed Asbestos and similar Asbestos products, Asbestos is only weakly bound with at the same time a relatively high weight fraction of up to > 60 wt -% Due to this weak binding, Asbestos fibers can be released to the environment in relatively high amounts from weathering or even light mechanical impacts.

4.3.1 Asbestos in Housing Construction

The use of sprayed Asbestos and similar Asbestos products with a very high fraction of Asbestos (generally > 60 wt.-%) is particularly problematic. Large amounts of Asbestos fibers can be released from these sources. Preferred areas of application for these materials were or are: (UBA-Report 5/91)

· fire protection, e.g.
wood wrappings, fill between ceilings, electrical wiring shafts, inner coatings for roofs,
ceilings, and walls, covering of openings, wrapping of air shafts and ventilation pipes
near fire shutters, etc.

· vibration protection, e.g.
ceilings and wall coatings, inner coatings of ventilation pipes

· thermal protection and humidity protection, e.g.
coatings of ceilings, fire extinguishing blankets, wrappings of steam and water pipes
and boiler units

· other uses, e.g.
gaskets, safety curtains, storage masses in heat recovery units, ventilation pipes made
of sheets, hot pads for pots

Products made of friable Asbestos are considered the greatest source of risk and are largely no longer permitted in the construction sector. Therefore, in the following, only nonfriable Asbestos materials are considered, which in particular are used in the form of roofing. The most important of these products are Asbestos cement corrugated sheets and Asbestos cement sheets.

Due to the high tensile strength of Asbestos fibers, which is achieved in spite of their fineness, Asbestos fibers are a favored reinforcing material for cement products. The resistance to tearing of e.g. chrysotile is like that of iron wire. Asbestos fibers are hollow, which accounts for their insulation capacity and the good attachment with all binding materials. Asbestos fibers do not burn, have a high melting point and are largely insensitive against chemicals. They are resistant to alkalis, salts, alcohols, mineral oils, and tar, and do not corrode and are resistant to dry gases.

Asbestos cement products show in general a limited resistance against moss formation, fungus accumulation or moulding. They are not resistant to acids, vegetable oils and fats, solutions of magnesium salts, sulfates, ammonium salts, iron chloride, warm distilled water and hot condensed water. Other harmful agents are chlorine, sulfur dioxide and smoke over long periods.

4.3.2 Asbestos in Water Mains

In water mains Asbestos cement pipes are particularly relevant due to their many technical properties. Asbestos cement pipes are normed for DN 65-600 and up to PN 16. The high tensile strength of Asbestos fibers ( 750-2250 N/mm² ) permits their use as reinforcing material in cement pipes.

The deciding criteria in the use of Asbestos cement pipes are the resistance against inner and outer corrosion for most soils and waters, the low weight for small nominal diameters, the simple manufacturing of the pipe joint, the mobility lengthwise, the bendability in the sockets and also the smooth pipe wall. The inner pressure of Asbestos cement pipes is generally 10 bar, or a maximum of 16 bar.

Aside from the health hazard, other negative aspects to be mentioned are: the low bending tensile strength, the very low breaking elongation, and the sensitivity against additional stresses primarily for small nominal diameters. In addition, special care is required for the transport and bedding of the pipes, and the pipeline fittings are partly made of other materials. Special measures are needed to take up the axial forces, and an additional effort arises for the processing of cut pipe ends, since the equipment must be permitted (prevention of Asbestos dust).

The application areas for Asbestos cement pipes are primarily in soils with relatively high corrosiveness and in rural areas. However, Asbestos cement pipes are not more resistant to corrosion than concrete pipes. In developing countries, primarily the H2S-corrosion of cement-bound materials needs to be considered.

<TOC5>> 4.4 Other application areas

Aside from the structural elements and other construction products, the so-called friction products are an important application area for Asbestos. These are primarily in the form of Asbestos containing brake and clutch linings, which are to some extent still found in numerous countries.

The many mechanical, physical and chemical properties of Asbestos have generated many additional application forms. Table 14 presents an overview of these Asbestos containing products. In total, Asbestos manufacturing (manufacturing of Asbestos containing products) amounts to about 30 - 40 million tons per year (1985).

Table 14: Summary of Asbestos Containing Products

Product

Average percent Asbestos

Binding Agent

Period of Use

Friction products

50

various polymers

1910 - present

Plastic products




Floor tile and sheet

20

PVC, asphalt

1950 - present

Coatings and sealants

10

Asphalt

1900 - present

Rigid plastics

< 50

Phenolic resin

? - present

Cement pipe and sheet

20

Portland cement

1930 - present

Paper products




Roofing felt

15

Asphalt

1910 - present

Gaskets

80

Various Polymers

? - present

Corrugated paper pipe wrap

80

Starches, sodium silicate

1910 - present

Other paper

80

Polymer, starches, silicates

1910 - present

Textile Products

90

Cotton, wool

1910 - present

Insulating and decorative products.




Sprayed coating

50

Portland cement, silicates, organic binders

1935 - 1978

Trowelled coating

70

Portland cement, silicates

1935 - 1978

Preformed pipe wrap

50

Magnesium carbonate, Calcium

1926 - 1975

Insulation hoard

30

silicate


Boiler insulation

10

silicate

unknown



Magnesium

1890 - 1978



carbonate, calcium silicate


Other Uses

< 50

Many types

1900 - present

Source: US-EPA Asbestos Waste Management Guidance - Generation. Transport, Disposal; 1985

Comment: The stated dates are to be taken relatively and can vary depending on the country; the term "present" indicates that these products can still be found.

Due to the combination of material properties, Asbestos is also used in street construction, in the manufacturing of rubber and tires and in the production of vehicles, airplanes and ships.

Table 15 shows the main uses of chrysotile Asbestos and their typical trade classifications.

Table 15: Usual Trade Classification of Chrysolite Asbestos

Classification*

Description

Primarily used for:

1

Crude 1

Woven textile, protective clothing, gasket

2

Crude 2

High quality It-sheets

3

Spun fiber

Pressure pipes, filters, etc.

4

Slate fiber

It-sheets, Asbestos cement sheets, pipes and formed pieces of pipe, gasket, Asbestos paper, spraying Asbestos, etc.

5

Long cardboard fiber

Asbestos cement sheets, Asbestos pipes, Asbestos singles, Asbestos cardboard for example for cushion-vinyl-lining, brake lining and clutch lining

6

Cardboard fibers

Clutch lining

7

Short fibers

Asbestos cardboard, friction lining, PVC-floor lining, and for casing of welding electrodes, etc.

8

Sand and waste


*) Classes 1 and 2 refer to hand-picked unprocessed Asbestos pieces with fibers of more than 19 mm (Crude 1) and of cat 9.5 to 19 mm lengths (Crude 2); Classes 3-8 refer to Asbestos qualities according to mechanical processing (milled fibers): Classification according to normed sifling methods of the QAPA (Quebec Asbestos Producers Association).

Source: Frank, K.: Asbestos Hamburg 1952, (cited from the UBA-Report 1180)

5. Occupational safety measures in handling Asbestos

The following alternatives are principally available as safety measures against fine Asbestos dust:

5.1 Suitable fiber binding

Since fine Asbestos particulates arise with every type of mechanical processing of Asbestos containing materials, it is necessary to reduce the release of fibers as far as possible by suitably binding them in the matrix. This can be achieved by selection of a suitable binding agent or through the lowest possible fiber amount (fiber number / unit weight).

Due to the very weak binding of sprayed Asbestos, it is one of the most hazardous applications. In most countries sprayed Asbestos is no longer permitted to be used. A relatively strong fiber binding is found in all Asbestos containing flat packing materials, in which the fibers are bound with elastomeres. In the relevant Technical Guidelines for Asbestos (Technischen Richtlinie fur Asbest, TRGS 517), it is therefore assumed that the exposure is below the limit when working with pressing and cutting tools. Other examples of Asbestos containing materials with relatively strong fiber binding are:

- grouting compounds, which are used in the electronic industry for the manufacturing of collectors

- yarns or bands impregnated with rubber or artificial resin, which are further processed by wrapping, calendering, pressing and hardening.

5.2 Wet operations

In many cases the release of fibers can be reduced by technical measures in processing the materials, for instance, by using slow running saws, instead of the abrasive cutter typically used in the past.

A further reduction in the release of fibers during the processing of Asbestos containing materials is achieved through the use of so-called wet operations. The following techniques are representative:

1. The processing of wet mixtures on calenders and form presses in the manufacturing of Asbestos cement, gaskets, friction linings, grouting compounds and filters;

2. The cutting of wet materials, e.g for construction parts made of Asbestos cement;

3. Forming and other processing of Asbestos cement products while wet;

4. Interweaving of moist Asbestos yarn.

However, with all of these techniques it must be noted that after drying, the material remains on the processing tools tend to release more fibers, and therefore special safety measures are needed during cleaning.

5.3 Enclosure

The best control of fine Asbestos dust exposure is achieved through enclosure of the working area. This prevents people from direct contact with Asbestos fibers and prevents fibers from reaching areas where people are situated. Enclosure is primarily used in the feeding of raw Asbestos to mixing and stirring plants for the manufacturing of materials. This process can be described as follows:

1. Asbestos fibers are brought in air-tight plastic sacks to the feeder.

2. The closed sacks are opened automatically in special facilities.

3. The Asbestos fibers are transported from the feeding point in closed conveyor systems to the processing point.

4. After the mixing process, the Asbestos fibers are embedded in moist binding agents, and additives and are brought in this state to the manufacturing station.

These process methods are state of the art for nearly all areas, such as production of Asbestos cement, friction linings, yarns, gaskets, and filters, as well as manufacturing of intermediate materials (mixtures, nonwoven, formed fabric, etc.).

In addition to the use of closed circuits, the avoidance of the generation of fine Asbestos dust in the processing of Asbestos containing materials is also possible through enclosure for discontinuous systems, e.g. automatic stamping, pressing and other mechancical processing operations in the manufacturing of e.g. gaskets and friction linings at stations with tool feeding and retrieval equipment. These processes can be characterized as follows:

1. The processing stations at which Asbestos dust arises are encapsulated dust-tight.
2. The operating personnel stand outside of the capsule.
3. The arising Asbestos dust from the processing is vacuumed up by an air exhaust cleaning unit.

A regular and careful cleaning of the processing station within the enclosure is important in order to prevent an accumulation of easily releasable fibers.

5.4 Vacuuming of dust near the point of origin

The processing of Asbestos containing materials to products, such as gaskets, brake and clutch linings, is only conditionally feasible in closed circuits or in the above-described enclosure. If in these cases, a nonpermissable generation of fibrous dust cannot be achieved through adequately strong binding of fibers in the materials, the arising dust must be directly vacuumed up at the processing point.

The main attention must be on the design of the vacuum element, which guarantees on the one hand that the fine dust does not reach the breathing area of the operating personnel, and on the other hand that the view and tasks of the operating personnel are not impaired. The vacuum element must also be fitted to the special requirements in each case. Basically, the vacuum elements should be positioned on the opposite side of the dust source from the operating person, so that the dust is vacuumed away from the breathing area.

With stamping and pressing machines, the machinery cleaning must be considered. These operations are generally not adequately performed by vacuuming, so that mechanical cleaning procedures are necessary. The cleaning of the machines should not be performed with compressed air guns.

If vacuuming directly at the site of origin is not possible or not adequately effective, an appropriate room ventilation system must be installed. The system of air conduction should be arranged in such a way that the personnel do not work in the stream of contaminated air. The efficiency of the room exhauster is typically less than that of vacuuming directly at the point of origin. With local dust accumulation, an uncontrolled elevation of concentration can temporarily arise.

Generally, the vacuumed air is permitted to be returned to the working area only under strict requirements. Stationary facilities of this kind require permits. The approval of the supervising authority (Trade Supervision Authority, Employers' Association for Accident Insurance) is only given in exceptional cases.

Financial studies show that direct vacuuming at the dust source is typically the less expensive alternative. The safety rules for air quality facilities at the workplace must be followed in operating the exhaust system.

5.5 Limiting the areas in which Asbestos dust may arise

Work areas in which Asbestos or Asbestos containing products are processed cannot typically be kept completely free of Asbestos dust, at least not through room air exhausting.

For this reason, such areas must be labelled and isolated so that the exposure cannot be carried over to neighboring rooms. This presumes an areal separation between Asbestos operations and others. Whether air transfer tubes are needed to prevent the spread of contaminated air depends on the individual case. Frequently, a slightly lower pressure in the contaminated area is sufficient.

The Asbestos particulates exhausted from the operating stations and rooms must be cleaned in particulate filters before being released outdoors. Filtering separators are used for the cleaning of Asbestos contaminated exhaust. The guideline value for the cleaned air emitted is defined as 0.1 mg/m³ in the Technical Instructions on Clean Air (Technischen Anleitung zur Reinhaltung der Luft).

5.6 Personal respiratory protection

If the required purity of air at the workplace cannot be maintained through technical or operational means, the workers at the workplace must wear respiratory protection. This basically applies when:

1. The particulate concentration exceeds the guideline value of 1x106 fibers/m³.

2. The limit of 0.25 X106 F/m³ is exceeded, and due to the process or the spatial and climatic conditions, elevated intake of fine Asbestos dust may occur via the lungs.

The wearing of respiratory protection should not be a permanent protection measure.

5.7 Regular and thorough cleaning of workplaces

The importance of regular and thorough cleaning of workplaces has already been emphasized by most of the safety measures. Which cleaning intervals need to be maintained depends on the operational circumstances. It is recommended to exactly prescribe the frequency based on experiences and measurements at individual workplaces and to monitor the compliance. This applies especially to work with rewards depending on productivity. Special attention should be given to the compliance with applicable regulations of the Employers Association for Accident Insurance (Berufsgenossenschaften).

The cleaning of workplaces is not only a technical and supervisory problem. Priority should be given to developing awareness of the problem among the workers through training and provision of information.

5.8 Dust-free waste collection and landfill disposal

Asbestos fibers and dust wastes. as well as Asbestos containing materials waste arising during the processes, and Asbestos containing dust from filters must be collected in dust-tight containers. In order to avoid unnecessary transferrals, these containers should also be usable for transportation.

For fine-grained Asbestos containing wastes, plastic bags with sufficient sturdiness can be used. Rough-edged pieces of waste should only be collected and transported in containers. For example, sealable drums in which the raw materials were delivered would be suitable. Furthermore, it should be tested whether moistening can further reduce particulate release. The wastes should be brought to permitted landfills under dust-free conditions. The further treatment should be negotiated with the responsible authorities.

6 Aspects of Asbestos abatement and disposal of Asbestos containing materials

Before Asbestos abatement using different methods is performed, it must first be clarified whether or not Asbestos materials are present. This trivial question represents a frequent problem in the practice of investigating old sites. Since in the developing countries specialized laboratories for definite microscopic determination of Asbestos fibers are not available in some cases, it is recommendable to analyze the building materials used. In Annex 5, examples of different Asbestos containing building materials are listed.

A visual investigation of the applied building materials by trained personnel is recommended as a first survey of potential Asbestos containing materials. Particular attention should be paid to fibrous and easily breakable building materials. The main application areas for Asbestos containing materials (see Part II Chapter 4) should be particularly investigated during the visual inspection.

Identification of the particularly hazardous sprayed Asbestos can also be performed visually to some extent: "Sprayed Asbestos is a white-gray, gray or gray-blue typically soft material which can be indented by the finger. The surface is typically scarred, even if it is protected with laitance or paint." (UBA-Report 5/91).

6.1 Evaluation guidelines on the urgency of abatement

The Asbestos Guidelines (Guidelines for the Evaluation and Abatement of Friable Asbestos Products in Buildings) describe the procedure for Asbestos abatement in Germany. These guidelines have proved effective in practice and are presented below.

On the basis of these rules the following criteria play a rule in evaluating the urgency of abatement:

· Type of Asbestos use
· Type of Asbestos
· Surface condition of the product (structure/damage)
· Impairment of the product from the outside
· Use of room
· Position of the product

The investigated object is assigned a grade on the urgency of abatement based on the above criteria.

The following urgency levels exist (see Evaluation form on the following page):

Urgency Level I

(>= 80 Points)

Abatement is required without delay



Such uses pose a definite hazard in the sense of Article 3 of the Framework Building Ordinance (Musterbau-ordnung). If abatement is not immediately possible, measures should be quickly undertaken to reduce the hazard by reducing the Asbestos fiber concentrations indoors. The final abatement should begin within 3 years.

Urgency Level II

(70-79 Points)

Abatement is required in mid-term.



A repeated investigation and evaluation is required at intervals of at most 2 years.

Urgency Level III

(< 70 Points)

Abatement is required in the long-term.



A repeated evaluation should be performed after a maximum of 5 years.

The form for the evaluation of the necessity of abatement with the weighting of individual criteria is presented on the following page. It is well-designed for a practical risk estimation.

6.2 Asbestos abatement techniques

After the urgency of abatement has been checked, abatement can basically be performed according to 3 methods:

Method 1: Removal

The removal of Asbestos is preferred when the Asbestos product has the following characteristics:

· poor physical condition,

· frequent repairs needed,

· exposed to vibrations and impacts,

· simple geometric form,

· necessary prerequisites for these methods are present (e.g. sufficient space for the removal technique and for the health and safety measures),

· no violations of necessary and required regulations concerning protection against fire, heat, noise or vibrations would result due to the elimination of the Asbestos product.

Standard Form for the Evaluation of Priority of Removal (Annex 1 of the Asbestos Remediation Guidelines)

Line

Groupe

Asbestos Products - Evaluation of Priority of Removal



Building:

Evaluation*

Corresponding Evaluation Grade



Room:





Product:




I

What kind of Asbestos hag been used?



1


Sprayed Asbestos

O

20

2


Asbestos containing wall finish

O

10

3


Lightweight Asbestos containing slabs

O

5

4


Other Asbestos containing products

O

5-20


II

Kinds of Asbestos



5


Blue Asbestos

O

2

6


Other Asbestos (white, gray)

O

0


III

Condition of surface/structure of Asbestos product



7


Loosened fiber structure

O

10

8


Firm fiber structure with or without sufficiently sealed surface cover

O

4

9


Laminated, sealed surface

O

0


IV

Surface condition/damage of Asbestos product



10


Heavy damages

O

6

11


Light damages

O

3

12


No damages

O

0


V

Exposure to wear / damages of Asbestos product



13


Damages of product due to direct access (floor to reaching height)

O

10

14


Occasional works done at product

O

10

15


Product is exposed to mechanical impacts

O

10

16


Product is exposed to vibrations

O

10

17


Product is exposed to extreme climatic changes

O

10

18


Product is exposed to excessive air flow

O

10

19


Excessive air circulations in room with Asbestos containing products

O

7

20


Improper operation may cause wear of product

O

0

21


No external damage to product possible




Vl

Room use



22


Room is used regularly by children, youths, athletes

O

25

23


Room is permanently or frequently used by other persons

O

20

24


Room is used temporarily

O

15

25


Room is rarely used

O

8


VII

Location of Asbestos product



26


Directly in room

O

25

27


In ventilation system of room (lining or jacket of leading ducts)

O

25

28


Behind a suspended unsealed ceiling or panel

O

25

29


Behind a suspended sealing ceiling or panel. behind dustproof lining or lamination. outside of tightly sealed ventilation ducts

O

0

30

Total Points of Evaluation




Removal:




31

urgently required

(Urgency level I)

O

80

32

required

(Urgency level II)

O

70-79


long range project

(Urgency level III)

O

70

* Check. when applicable. If more than one item was checked in one group, use only one - the highest evaluation figure. when total is calculated (Line 30).

Method 2: Encapsulation

This Asbestos abatement method is generally preferred if the Asbestos product:

· has sufficient resistance to ripping,
· has a hard, sealed surface,
· is not worn through repairs and physical impacts,
· has a complicated geometric form,
· is hard to reach,

or

· if the Asbestos product cannot be removed for reasons of protection against fire, heat, noise and /or vibrations.

Method 3: Enclosure

Is to be applied, if the Asbestos product:

· is in perfect physical condition,

· is located on easily accessible building parts with simple geometric forms and dimensions which are not too large,

· lies in an area endangered by physical impacts,

or

· if the Asbestos product cannot be removed from the site for reasons of protection against fire, heat, noise and/or vibrations.

The following page presents the decision process for the selection of the Asbestos abatement method to be applied.

The selection of the abatement method is primarily dependent on the condition of the Asbestos containing material. The removal of the material is appropriate in most cases, as long as the listed restrictions are not the determining factors. Removal is also the only permanent solution. With the other two methods of enclosure as well as encapsulation, it should be noted that in a later state, e.g. during building demolition, the Asbestos containing material will have to be removed. From this standpoint, both of these latter methods represent only a time-limited intermediate solution.


Figure 3: Selection of the Potential Abatement Method

Furthermore, enclosure can only be applied, if it is possible to isolate Asbestos containing materials in narrowly defined regions. Additionally, it must be noted that constant and regular inspections are necessary or ensure proper health protection.

With encapsulation, it should be considered that in some cases the later removal of the Asbestos containing substances might be more difficult and therefore more expensive.

In general, the abatement methods "encapsulation" as well as "enclosure" should only be performed, if the Asbestos containing materials are in good condition.

Aside from these rather general considerations, the actual case is certainly decisive, namely: which Asbestos containing materials in which amounts and in which condition are to be abated under consideration of relevant secondary considerations (e.g. form of use).

In Annex 6, the advantages and disadvantages of the individual abatement methods are summarized together in a table from the US EPA Guidance For Controlling Asbestos-Containing Materials In Buildings, 1985.

6.3 Disposal of Asbestos containing materials

Although nearly a complete substitution of Asbestos containing products is currently possible, in the future further increases in the arisings of Asbestos containing wastes are expected, since many of the products produced in the past are nearing the end of their lifespan. Asbestos abatement projects are another source of Asbestos containing wastes.

The main portion of Asbestos containing wastes arise from building materials (Asbestos cement and sprayed Asbestos). For a long time the disposal situation was such that these materials could be mixed with other building debris in a more or less carefree manner, and be deposited at landfills for building debris and excavated soil, (IACS, S. 12.1 ) without provision of measures against dust formation and possible Asbestos fiber release.

Just the more recent national and supra-national legislation considers the hazard of Asbestos containing wastes. The Basel Convention against cross-boundary transport of wastes, for example, lists Asbestos containing wastes in the catalogue of substances to be controlled. The EC-Guideline 78/319/EEC from 1978 also categorizes Asbestos dust and fibers as hazardous wastes. The federal German waste legislation treats Asbestos dust and sprayed Asbestos as wastes requiring particular supervision according to Article 2 Para. 2 of the Waste Law (§ 2 Abs.2 AbfG). The foreseen disposal paths are: deposition at a special waste landfill or domestic waste landfill, as well as chemical/physical treatment.

Based on the environmental relevance of Asbestos containing substances, there are no arguments against the deposition at domestic waste landfills, since no special measures are necessary regarding discharge of leachate with subsequent potential soil and groundwater contamination. The environmental relevance of Asbestos containing wastes arises from the health damaging effect from Asbestos exposure. For this reason, fiber emissions during the disposal are to be minimized. There are relatively simple possibilities for this minimization of emissions:

· Encapsulation with binding agent (cement)
· Reduce dust by maintaining wet conditions
· Transport Asbestos containing wastes in closed containers

The German States' Working Group on Wastes (Landerarbeitsgemeinschaft Abfall, LAGA) have published instructions on the disposal of Asbestos containing wastes with the following recommendations:

1. Abestos containing wastes are not reusable/recyclable.

2. The incineration of Asbestos containing wastes is not allowed.

3. Asbestos dust and wastes with friable Asbestos and other Asbestos containing wastes in which Asbestos fibers can easily be released are to be treated so that they can be disposed of at domestic waste landfills or mono-landfills. The treatment includes basically the encapsulation with hydraulic binding agents, if possible at the site of origin.

4. Wastes with nonfriable Asbestos fibers should be kept moist until they are deposited at the landfill (mono or domestic wastes), in order to avoid dust generation.

In summary, the transport and disposal of Asbestos containing wastes should be performed using measures to prevent dust development and the release of Asbestos fibers. Firm binding, e.g. with cement, is recommended for the final deposition.

TO PREVIOUS SECTION OF BOOK TO NEXT SECTION OF BOOK