|New Asbestos Detection Limit Practice Under Development
A new Standard Practice for Determining a Detection Limit for
Asbestos Measurements Based on Counts is being developed by scientists
serving on ASTM Subcommittee D22.07 on Sampling and Analysis of
Asbestos under Committee D22 on Sampling and Analysis of Atmospheres.
In the final stages of development at ASTM, the proposed detection
limit practice applies to asbestos in air samples measured by
phase contrast microscopy or transmission electron microscopy,
and asbestos in dust measured by transmission electron microscopy.
Nearly 20 scientists drafting the standard collaborated on the
specific requirements of asbestos fiber-counting, instrumentation,
and protocol, according to D22 member Naomi S. Montague, vice
president, E. M. Analytical, Inc., Dania, Fla.
Montague said the detection-limit concept addresses potential
measurement interpretation errors: For our subcommittee, the
detection limit is a parameter that is used to determine whether
the fiber measurement in a sample is statistically different than
the background level. To date, no formal method or practice for
determining a detection limit for asbestos measurements is available
from ASTM or any other organization.
The methods for sampling and analysis of asbestos that our subcommittee
has published (as well as all other published methods) have employed
a definition of detection limit that has become accepted only
because of convention and the passage of time. This practice now
allows our subcommittee to provide a definition of detection of
limit and a constructive procedure for determining its numerical
value that is scientifically sound.
For further technical information, contact Bertram Price, Price Associates, Inc. (phone: 202/457-9007). Committee D22
meets April 2-5 in Phoenix, Ariz. For meeting or membership details,
contact Director George Luciw, ASTM (phone: 610/832-9710). //
Copyright 2001, ASTM