ASTM D8068-19

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D8068 − 18 D8068 − 19
Standard Practice for
Collection of Culturable Airborne Fungi or Bacteria on Agar
Plates by Inertial Impaction Systems
This standard is issued under the fixed designation D8068; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This practice was introduced to bring uniformity to the process of sample collection for culturable
fungi or bacteria using inertial impaction samplers for analysis by culture and optical microscopy.
1. Scope
1.1 The purpose of this practice is to describe procedures for the collection of culturable airborne fungal spores or fragments
or bacteria on agar plates using inertial impaction sampling techniques.
1.2 This practice does not include collection of culturable fungi or bacteria by devices not using agar plates.
1.3 This practice presumes that the user has a fundamental understanding of field investigative techniques related to the
scientific process, and sampling plan development and implementation. It is important to establish the related hypothesis to be
tested and the supporting analytical methodology needed in order to identify the sampling media to be used and the laboratory
conditions for analysis.
1.4 This practice does not address the development of a formal hypothesis or the establishment of appropriate and defensible
investigation and sampling objectives. It is presumed the investigator has the experience and knowledge base to address these
issues.
1.5 This practice does not provide the user sufficient information to allow for interpretation of the analytical results from sample
collection. It is the user’s responsibility to seek or obtain the information and knowledge necessary to interpret the sample results
reported by the laboratory.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D3195/D3195M Practice for Rotameter Calibration
D6044 Guide for Representative Sampling for Management of Waste and Contaminated Media
D3195/D3195M Practice for Rotameter Calibration
E2589 Terminology Relating to Nonsieving Methods of Powder Characterization
This practice is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.08 on Assessment, Sampling, and
Analysis of Microorganisms.
Current edition approved Nov. 1, 2018March 1, 2019. Published November 2018March 2019. Originally approved in 2018. Last previous edition approved in 2018 as
D8068 – 18. DOI: 10.1520/D8068-18.10.1520/D8068-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8068 − 19
F1671 Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Blood-Borne Pathogens Using
Phi-X174 Bacteriophage Penetration as a Test System
3. Terminology
3.1 Definitions—For definitions of terms used in this practice, see Terminology D1356.
3.1.1 agar, n—a semisolid culture medium used to support the growth of bacteria and other micro-organisms. F1671
3.1.2 sample, n—a portion of a population.
3.1.2.1 Discussion—
A portion of material that is taken for testing or record purposes. D6044
3.1.3 sample, representative, n—a sample collected in such a manner that it reflects the characteristics of interest of a population
(as defined) from which it is collected.
adapted from D6044
3.1.3.1 Discussion—
A population in the context of this standard refers to culturable fungi- or bacteria colony-forming units that exist at the time and
location of sampling.
3.1.4 sampling train, n—the assemblage of equipment necessary to sample atmospheres. D1356
3.1.4.1 Discussion—
Complete assembly from the pump system through to the agar plate including any transport tubing and connectors.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 aerodynamic diameter (d ), n—the diameter of a unit density sphere that has the same inertial properties as the particle
a
under analysis under the same conditions. E2589 – 09
3.2.1.1 Discussion—
For fungal spores, this is generally based on a water droplet (spherical particle) having a density of 1 g/cm . Aerodynamic diameter
has been developed to categorize the sizes of particles of different shapes and densities with a single dimension. The aerodynamic
diameter is not necessarily equal to the physical diameter due to variations in shape or density.
3.2.1 bacteria, n—any of a class of microscopic prokaryotic organisms reproducing by fission or by spores.
3.2.2 chain of custody (COC), n—a document that provides for the traceable transfer of field samples to the analytical
laboratory.
3.2.2.1 Discussion—
The COC may or may not be combined with the Field Data Sheet.
3.2.3 fungus (s), fungi (pl), n—eukaryotic, heterotrophic, absorptive organisms that usually develop a rather diffuse, branched,
tubular body (that is, network of hyphae) and usually reproduce by means of spores. adapted from Kendrick
3.2.3.1 Discussion—
The terms ‘mold’ and ‘mildew’ are frequently used by laypersons when referring to various fungal colonization.
3.2.4 inertial impactor, n—a device designed for the collection of particles that are separated from the air stream by inertia to
force the impact onto an adhesive surface.
3.2.4.1 Discussion—
Kendrick, B., The Fifth Kingdom, Focus Publishing / R. Pullins and Co, 2008.
D8068 − 19
Inertial impactors are available in many designs and include both ‘multi-orifice’ (also known as ‘multiple-hole’ or ‘sieve plate’)
and ‘slit to agar’ (also known as rotating slit) samplers.
4. Significance and Use
4.1 This practice is intended for the collection of airborne particles on agar plates using inertial impaction for the purpose of
culturing fungi or bacteria.
4.2 This practice is valuable when species level identification or quantity of culturable aerosolized fungi and bacteria are
important factors for the indoor air quality investigation.
4.3 It is the responsibility of the user to assure that they are in compliance with all local, state, and federal regulations governing
the inspection of buildings for fungal and bacterial colonization and the collection of associated samples.
4.4 This practice is intended to provide the user with a basic understanding of the equipment, materials, and instructions
necessary to effectively collect air samples on agar plates using an inertial impactor.
4.5 This practice is intended to minimize systematic sampling variations between different data sets.
D8068 − 19
5. Preparation of Sampling Equipment
5.1 Equipment List:
5.1.1 Sampling Train—The combination of components from the pump or fan system through to the agar plate including any
transport tubing, flow controller, and connectors. The configuration may be an integrated assembly or components that have been
configured with an external pump.
NOTE 1—Rotary vane, diaphragm, linear magnetic, piston, and fan driven devices may have the open flow capacity for specific impactors; however,
resistance to flow through the impactor can dramatically reduce flow rates. Care must be taken to select a pump and calibrator that are compatible with
impactors to set and measure flow rates properly.
5.1.1.1 For external pump assemblies, use flexible tubing and connector
...