Environmental Protection Agency Pt. 763, Subpt. E. App. A
an accredited inspector under para with each fiber closer than one fiber diame
graphs (a) (3). (4). (5) of this section, or ter.
an architect, project engineer or ac 5. Clean area—At controlled environment
which is maintained and monitored to assure
credited inspector under paragraph a low probability of asbestos contamination
(a)(7) of this section, the local edu to materials In that space. Clean areas used
cation agency shall have 180 days fol in this method have HEPA filtered air under
lowing the date of identification of positive pressure and are capable of sus
ACBM to comply with this subpart E. tained operation with an open laboratory
blank which on subsequent analysis has an
Appendix A to Subpart E—Interim average of less than 18 structure^mm’ in an
Transmission Electron Micros area of 0,057 mm^ (nominally 10 200-mesh grid
copy Analytical Methods—Man
openings) and a maximum of 53 structures/
mm^ for any single preparation for that same
datory AND Nonmandatory—AND area.
Mandatory Section to Determine 6. Cluster—Ai. structure with fibers in a ran
Completion of Response Actions dom arrangement such that all fibers are
Intermixed and no single fiber is Isolated
/. Introduction from the group. Groupings must have more
The following appendix contains three than two Intersections.
units. The first unit is the mandatory trans 7. £■£»—Electron diffraction.
mission electron microscopy (TEM) method 8. EDAA—Energy dispersive X-ray anal
which all laboratories must follow: it is the ysis.
minimum requirement for analysis of air 9. Fiber—A structure greater than or equal
samples for asbestos by TEM. The manda to 0.5 gm in length with an aspect ratio
tory method contains the essential elements (length to width) of 5:1 or greater and having
of the TEM method. The second unit con substantially parallel sides.
tains the complete non-mandatory method. 10. Grid—AiH open structure for mounting
The non-mandatory method supplements the on the sample to aid in its examination in
mandatory method by including additional the TEM. The term is used here to denote a
steps to improve the analysis. EPA rec 200-mesh copper lattice approximately 3 mm
ommends that the non-mandatory method be In diameter.
employed for analyzing air filters; however. 11. Intersection—Nonparallel touching or
the laboratory may choose to employ the crossing of fibers, with the projection having
mandatory methrxi. The non-mandatory an aspect ratio of 5:1 or greater.
method contains the same minimum require 12. Laboratory sample coordinator—That per
ments as are outlined in the mandatory son responsible for the conduct of sample
method. Hence, laboratories may choose ei handling and the certification of the testing
ther of the two methods for analyzing air procedures.
samples by TEM. 13. Filter background level—The concentra
The final unit of this Appendix A to sub tion of structures per square millimeter of
part E defines the steps which must be taken filter that is considered indistinguishable
to determine completion of response actions. from the concentration measured on a blank
(filters through which no air has been
This unit Is mandatory. drawn). For this method the filter back
II. Mandatory Transmission Electron ground level is defined as 70 structures/mm^.
Microscopy Method 14. Matrix—Fiber or fibers with one end
free and the other end embedded in or hidden
A. Definitions of Terms by a particulate. The exposed fiber must
meet the fiber definition.
1. Analytical sensitivity—Airborne asbestos 15. NSD—tio structure detected.
concentration represented by each fiber 16. Operator—A person responsible for the
counted under the electron microscope. It is TEM instrumental analysis of the sample.
determined by the air volume collected and 17. PCM—Phase contrast microscopy.
the proportion of the filter examined. This 18. SAED—Selected area electron diffrac
method requires that the analytical sensi tion.
tivity be no greater than 0.005 structures/ 19. SEM—Scanning electron microscope.
cm’. 20. STEM—Scanning transmission electron
2. Asbestiform—A specific type of mineral microscope.
fibrosity in which the fibers and fibrils pos 21. Structure—a microscopic bundle, clus
sess high tensile strength and flexibility. ter, fiber, or matrix which may contain as
3. Aspect ratitr—A ratio of the length to the bestos.
width of a particle. Minimum aspect ratio as 22. S'cnF—Structures per cubic centimeter.
defined by this method is equal to or greater 23. S/mnF—Structures per square milli
than 5:1. meter.
4. Bundle—A structure composed of three 24. TEM—Transmission electron micro
or more fibers in a parallel arrangement scope.
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NYC-WTC_000149395Source: NYC Law Department, mirrored locally