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close this bookAsbestos Overview and Handling Recommendations (GTZ, 1996)
close this folderPart II. Asbestos
close this folder6 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

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.