ASTM D4597-10(2021)

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.
Designation: D4597 − 10 (Reapproved 2021)
Standard Practice for
Sampling Workplace Atmospheres to Collect Gases or
Vapors with Solid Sorbent Diffusive Samplers
This standard is issued under the fixed designation D4597; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers the sampling of workplace atmo-
D1356Terminology Relating to Sampling and Analysis of
spheresforthepresenceofcertaingasesorvaporsbymeansof
Atmospheres
diffusion across a specified quiescent region and subsequent
D3686Practice for Sampling Atmospheres to Collect Or-
sorption on a solid sorbent (1).
ganic Compound Vapors (Activated Charcoal Tube Ad-
1.2 A list of organic compounds which are applicable to
sorption Method)
solid sorbent sampling where the sorbent is contained in a bed
D3687Test Method for Analysis of Organic Compound
through which air is passed is given in Annex A1 of Practice
VaporsCollectedbytheActivatedCharcoalTubeAdsorp-
D3686. Diffusive samplers may be applicable to a similar
tion Method
rangeofcompoundsbutthismustbeconfirmedbyreferenceto
D6306Guide for Placement and Use of Diffusive Samplers
the individual sampler manufacturer’s literature.
for Gaseous Pollutants in Indoor Air
2.2 Other Document:
1.3 The valid use of diffusive samplers depends on the
Title 29CFR 1910.1000Subpart Z, Occupational Health and
existence of actual laboratory or field validation, or both.
Safety Standard
Guidance on validation can be obtained from published proto-
cols (2-6). This practice is not designed to cover the
3. Terminology
verification, validation, or specific test procedures used to
assess the accuracy or precision of diffusive samplers.
3.1 Definitions—For definitions of terms used in this
practice, refer to Terminology D1356.
1.4 The values stated in SI units are to be regarded as
3.2 Definitions of Terms Specific to This Standard:
standard. No other units of measurement are included in this
3.2.1 diffusion, n—the movement of gas or vapor molecules
standard.
from a region of high concentration to a region of low
1.5 This standard does not purport to address all of the
concentration as described by Fick’s first law (8.1).
safety concerns, if any, associated with its use. It is the
3.2.2 diffusive sampler, n—assembly used for sampling gas
responsibility of the user of this standard to establish appro-
or vapor molecules from the atmosphere.
priate safety, health, and environmental practices and deter-
3.2.3 sampling rate, n—the ratio of mass of a given com-
mine the applicability of regulatory limitations prior to use.
pound collected by a diffusive sampler per unit time of
1.6 This international standard was developed in accor-
exposure to the concentration of that compound in the atmo-
dance with internationally recognized principles on standard-
sphere being sampled.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.2.3.1 Discussion—The sampling rate is sometimes re-
ferredtoastheuptakerate.Unitsareng(ormg)/mg/m /min(or
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. h), which are dimensionally equivalent to a volume flow-rate
(for example cm /min).
This practice is under the jurisdiction of ASTM Committee D22 on Air
Qualityand is the direct responsibility of Subcommittee D22.04 on WorkplaceAir For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Quality. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved March 1, 2021. Published March 2021. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1987. Last previous edition approved in 2015 as D4597–10 (2015). the ASTM website.
DOI: 10.1520/D4597-10R21. Code of Federal Regulations available from U.S. Government Printing Office,
The boldface numbers in parentheses refer to a list of references at the end of Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-
this standard. 0001, http://www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4597 − 10 (2021)
4. Summary of Practice 6.6 Errors may arise in estimating exposure using diffusive
samplers in instances in which the concentration of the gas or
4.1 Molecules (gases and vapors) are sampled from the
vapor being sampled varies significantly over time.
atmosphere by a diffusive sampler. During the sampling
6.7 Where multiple gases or vapors are sampled
process, the molecules diffuse from the environment adjacent
simultaneously, care must be exercised to ensure there is no
to the sampler through a region of defined geometric structure
mutual interference in the analytical method chosen.
andintoaregioncontainingthesorbentmedium.Thetheoryof
diffusive sampling is given in this practice.
7. Apparatus
4.2 Instructionsaregivenforthecorrectuseofthesampling
7.1 Diffusive Sampling Devices:
devices to enable their field application.
7.1.1 A diffusive sampler consists of a cavity or group of
4.3 Informationonthecalculationofenvironmentalconcen-
cavities containing air and terminated at one end by a sorbent
tration based on sampler assay is given.
substrate and opening at the other to the environment. The
cavity or group of cavities form a region of defined geometry
5. Significance and Use
whichactsasacontrolontherateofgaseousdiffusionfromthe
external environment to the sorbent substrate. Barriers to the
5.1 Regulations such as those promulgated by the U.S.
entry of external air movements are common. Samplers where
OccupationalSafetyandHealthAdministrationinTitle29CFR
the diffusion of gas or vapor is through materials other than air
1910.1000 designate that certain hazardous gases and vapors
are covered by this practice, but it should be noted that the
must not be present in the workplace air at concentrations
influence of temperature on diffusion may be more pro-
above specific values.
nounced.
5.2 Thispractice,whenusedinconjunctionwithananalyti-
7.1.2 Diffusive samplers are equipped with a means of
caltechnique,suchasthatgivenfororganiccompoundsinTest
attachment to the body for personal sampling or to a suitable
Method D3687, may provide a means for the determination of
support for area sampling. Samplers are contained in vapor
time-weighted airborne concentrations of many of the hazard-
impermeable packages or are sealed with vapor impermeable
ous gases and vapors in applicable regulations (for example,
caps both before and after sampling. Labels for unique identi-
Title 29CFR 1910.1000), as well as others.
fication of a collected sample are required.
5.3 The manufacturer’s literature should be consulted for
8. Diffusive Sampling Theory
the appropriate list of chemicals which may be sampled by a
8.1 Fick’s first law of diffusion states that for a constant
particular device.
concentration gradient, the mass of material transferred to the
sampling layer can be expressed as follows:
6. Interferences
DA
6.1 The diffusive sampling process can be jeopardized by
M 5 ~C 2 C !t (1)
o
L
physicalblockageofentrancestotheinteriorofthedevicesuch
as by liquid droplets or dust particles.
where:
M = mass of material, ng,
6.2 The diffusive sampling process can be jeopardized by
D = diffusion co-efficient, cm /min (Note 1),
structural damage to any membranes or other elements used to
A = crosssectionalareaofdiffusioncavity(ies),cm (Note 2),
control either the geometry of the diffusion path or turbulence
L = length of diffusion path, cm (Note 3),
within the diffusion path.
C = gas phase concentration at face of sampler, ng/cm ,
6.3 The diffusive sampling process can be jeopardized by
C = gasphaseconcentrationatsorbentsurface,ng/cm ,and
o
t = exposure time, min.
air movement within the diffusion path. Recent sampler de-
NOTE 1—The diffusion coefficient of a molecule is a function of the
signs have incorporated elements to decrease this possibility.
temperature and the nature of the medium through which it is diffusing.
6.4 The diffusive sampling process can be jeopardized by
Shouldthemediumbeacompressiblefluid(forexample,air)thediffusion
insufficient mixing of the air external to the sampler. This is coefficient will also be a function of the pressure.
NOTE 2—The presence of barriers to the entry of external air move-
known as starvation. The manufacturer should provide a
ments may alter the effective cross-sectional area of the sampler.
recommended minimum ambient air velocity, below which the
NOTE 3—Under certain circumstances the length of the diffusion path
sampler should not be used.
canbesignificantlyextendedintothethicknessofthesorbentlayerduring
sampling. Certain types of sampler make use of this phenomenon to give
6.5 Thediffusivesamplingprocesscanbejeopardizedifthe
a length of stain read-out. In this situation, the mathematical treatment of
concentration in air at the sorbent interface becomes sufficient
Fick’s law is more complex than that given here.
to significantly alter the diffusion gradient within the diffusion
8.2 The sampling rate (SR) of a diffusive sampler for a
path.Thiscanoccurthroughsorbentsaturation,eitherfromthe
specific gas or vapor may be expressed as follows:
presenceofcompetingspecies(whichmayincludewatervapor
DA M
molecules), or the selection of an inappropriate sorbent mate-
SR 5 5 (2)
L ~C 2 C !t
rialfortheconcentrationandtimeofexposure,orbyincreased
o
temperature. The manufacturer should provide, or the user
where:
should determine, the range of conditions over which signifi-
SR = sampling rate, cm /min.
cant bias from sorbent saturation will not occur.
D4597 − 10 (2021)
where: 9.2.1.4 Record all pertinent information such as
concentration (C, C ) is given in ppm (v/v) the units of SR temperature, barometric pressure, relative humidity, ambient
o
become ng/ppm/min. air velocity (for area samples), and gases and vapors being
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