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Title TEM Analysis Field Sampling Guide

Field Sampling Guide

Asbestos by TEM

The following field sampling guide is designed for use as a reference for the field consultant. It summarizes procedures and techniques for the sampling of asbestos for analysis by TEM, as they impact the analytical process.

For additional information on field sampling equipment, field health and safety, regulatory requirements for field sampling, sampling strategies and data interpretation, refer to the appropriate documented methodology and/or regulatory agency.



Collection Media

Recommended Volume

Detection Limit


Clearance Level

(not yet available)



40 CFR Part 763 (AHERA)

25 mm MCE filter with pore size <0.45 microns

> 1200 liters

0.005 s/cc

Unsampled cassette. 2 per set of 10


-if less than 1200 liters are collected, the screening for clearance cannot be used (mean < 70s/mm2). The laboratory may also inquire as to the need for 0.005 analytical sensitivity

-method is based on a sample set (collected on required media) which includes 5 inside and 5 outside samples, with 3 blanks. Report will contain a disclaimer for samples submitted otherwise


D 6281-98

25 to 50 mm cassette with pore size 0.45 micron

pending desired analytical sensitivity

calculated airborne structure concentration equivalent to 2.99 structures counted in the analysis

Unsampled cassette


-analysis reports fibers > .5 microns

-this method is used primarily as an alternative to AHERA. Applicability to regulatory limits should be determined prior to use


NIOSH 7402

.45 Cellulose ester membrane, 25mm; conductive cowl on cassette

400 – 1800 liters @ flow rate 2-10 L/min

one confirmed fiber > 95% of mean blank value

Unsampled cassette.

2 to 10 per set


method is used to determine asbestos fibers in the optically visible range and is intended to complement the results obtained by PCM (NIOSH 7400)


D 5755-95

25 mm or 37 mm MCE with pore size < 0.8 microns with plastic tubing cut at a 450 angle

100 cm2 with a minimum of 2 min. sampling time

4 structures per TEM analysis

Unsampled cassette. 1 per sample set


there are currently no clearance guidance levels for data from this analysis. available are suggested guidelines only.

Dust on Wipe

D 6480-99

particle free, sealed edge continuous filament cloth. ‘clean room wiper’

typically 100 cm2 , using a template

2.99 X calculated asbestos structures/cm2

Unsampled wipe


-template size can vary. results will be reported in asbestos structures/ cm2


EPA 100.2 (and 100.1)

1 liter polyethylene or glass container. sample containers should be analyzed for background level (blank determination) prior to sample collection.

should be collected in duplicate. 800 mls in 1 liter bottles and stored in the dark at 40 C. sample are to be shipped in order to be filtered at the laboratory within 48 hrs.

0.2 MFL (million fibers per liter)

-blank checks should be performed prior to sample collection.

-polyethylene bottles- one bottle from each batch or minimum of one from each 24

-glass bottles – four bottles from each 24.

-additional blanks may be desirable if low levels are suspected.


- method 100.2 counts fibers > 10 microns only

-100.2 is typically used for drinking water analysis

-100.1 is typically used for waste water analysis

-acceptable blank levels are < 0.01 MFL >10 microns in length

-time of collection should be recorded on the chain of custody as holding times effect the analysis. (see collection media column)

-information should be supplied to indicate if the samples come from bulk storage supply of from a distribution system (if collected in California).

-composting must be done in the laboratory, not the field.


New York State ELAP 198.4 and Chatfield Method


> 1 gm



-This method is intended for use in identifying and quantitating asbestos in non –friable organically bound (NOB) bulk materials. Use of this method for sample types other than NOB can produce results that may not provide the analytical reliability for which the method was intended.




1 cubic inch for materials such as floor tiles.




-The TEM section of this method is designed to provide a method for the detection of thin fibers below the resolution limit of optical microscopy

- Detection limits can vary with sample type, amount of sample analyzed or method of quantitation used.



The laboratory manager will contact the responsible party in the event there is a question on sample integrity. These may include circumstances which may include (but are not limited to):

    • Analysis requested outside laboratory’s scope of accreditation
    • Analysis requested outside laboratory capability (such as lack of equipment or staffing resources).
    • Obviously damaged or compromised samples, i.e. opened air cassettes, cassettes with torn or ripped filters.
    • Improper labeling
    • Improper packaging
    • Impossible deadlines
    • Obvious faulty sampling technique
    • Improper sample media
    • Incompatible samples packaged together (i.e.- air samples with bulk samples)
    • Inappropriate analytical methodology requested

There are a variety of field conditions, which can effect the analytical process. These include:

Air Samples

Sample overload -

  • The direct analytical method cannot be used if the general particulate matter loading of the sample collection filter as analyzed exceeds approximately 10% coverage of the collection filter by particulate matter

Wet filter – a wet filter can not be analyzed

Water Samples

Analytical Sensitivity may be elevated do to interfering matrices contained in the sample

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