ASTM F739-20

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.
´1
Designation: F739 − 12 F739 − 20
Standard Test Method for
Permeation of Liquids and Gases Through Protective
Clothing Materials Under Conditions of Continuous Contact
This standard is issued under the fixed designation F739; 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.
ε NOTE—Editorially corrected 8.8.1 in February 2015.
INTRODUCTION
Workers involved in the production, use, and transportation of liquid and gaseous chemicals can be
exposed to numerous compounds capable of causing harm upon contact with the human body. The
deleterious health effects of these chemicals can range from acute trauma such as skin irritation and
burn, to chronic degenerative disease such as and mutagenic conditions, including cancer. Since
engineering controls may not eliminate all possible exposures, attention is often placed on reducing
the potential for direct skin contact through the use of protective clothing that resists permeation,
penetration, and degradation.
This test method is used to measure the permeation of liquids and gases through protective clothing
materials under the conditions of continuous contact of the clothing material by the test chemical.
Resistance to permeation under the condition of intermittent contact with the test chemical should be
determined by Test Method F1383. In certain situations, the permeation of liquids through protective
clothing materials can be measured using a permeation cup following Test Method F1407. Penetration
of liquids should be determined by Test Method F903. An undesirable change in the physical
properties of protective clothing materials is called degradation. Procedures for measuring the
degradation of rubbers, plastics, and coated fabrics are found in Test Method D471, Test Method
Practice D543, and Test Method D751, respectively. A starting point for selecting the chemicals to be
used in assessing the chemical resistance of clothing materials is Guide F1001.
1. Scope
1.1 This test method measures the permeation of liquids and gases through protective clothing materials under the condition of
continuous contact.
1.2 This test method is designed for use when the test chemical is a gas or a liquid, where the liquid is either volatile (that is,
having a vapor pressure greater than 1 mm Hg at 25°C)25 °C) or soluble in water or another liquid that does not interact with the
clothing material.
1.3 Values states in SI units are to be regarded as standard. Values given in parentheses are not exact equivalents and are given
for information only.
This test method is under the jurisdiction of ASTM Committee F23 on Personal Protective Clothing and Equipment and is the direct responsibility of Subcommittee
F23.30 on Chemicals.
Current edition approved Sept. 1, 2012Nov. 1, 2020. Published October 2012November 2020. Originally approved in 1981. Last previous edition approved in 20072012
as F739 – 07.F739 – 12. DOI: 10.1520/F0739-12E01.10.1520/F0739-20.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F739 − 20
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 7.
1.5 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:
D471 Test Method for Rubber Property—Effect of Liquids
D543 Practices for Evaluating the Resistance of Plastics to Chemical Reagents
D751 Test Methods for Coated Fabrics
D1777 Test Method for Thickness of Textile Materials
E105 Practice for Probability Sampling of Materials
E171E171/E171M Practice for Conditioning and Testing Flexible Barrier Packaging
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
F903 Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Liquids
F1001 Guide for Selection of Chemicals to Evaluate Protective Clothing Materials
F1194 Guide for Documenting the Results of Chemical Permeation Testing of Materials Used in Protective Clothing
F1383 Test Method for Permeation of Liquids and Gases Through Protective Clothing Materials Under Conditions of
Intermittent Contact
F1407 Test Method for Resistance of Chemical Protective Clothing Materials to Liquid Permeation—Permeation Cup Method
F1494 Terminology Relating to Protective Clothing
F2815 Practice for Chemical Permeation Through Protective Clothing Materials: Testing Data Analysis by Use of a Computer
Program (Withdrawn 2019)
2.2 ISO Standard:
ISO 6529 Protective Clothing—Determination of Resistance of Protective Clothing Materials to Permeation by Liquids and
Gases
3. Terminology
3.1 Definitions:
3.1.1 analytical technique, n—a procedure whereby the concentration of the test chemical in a collection medium is quantitatively
determined.
3.1.1.1 Discussion—
These techniques are often specific to individual chemical and collection medium combinations. Applicable techniques include,
but are not limited to,to: flame ionization, photo ionization, electro-chemical, ultraviolet and infrared spectrophotometry, gas and
liquid chromatography, colorimetry, length-of-stain detector tubes, and radionuclide tagging/detection counting.
3.1.2 breakthrough detection time, n—the elapsed time measured from the initial exposure to the test chemical to the sampling
time that immediately precedes the sampling time at which the test chemical is first detected.
3.1.2.1 Discussion—
(See Fig. 61.) The breakthrough detection time is dependent on the sensitivity of the method (see Appendix X1).
3.1.3 closed-loop, adj—refers to a testing mode in which there is no change in the volume of the collection medium except for
sampling.
3.1.4 collection medium, n—a liquid, gas, or solid that absorbs, adsorbs, dissolves, suspends, or otherwise captures the test
chemical and does not affect the measured permeation.
3.1.5 cumulative permeation, n—the total mass of chemical that permeates a specific area of protective clothing material during
a specified time from when the material is first contacted by the test chemical.
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.
The last approved version of this historical standard is referenced on www.astm.org.
F739 − 20
NOTE 1—Cell can be reconfigured for gas challenges. Collection chamber can be used in open- or closed-loop mode. Closed chamber is to right of
sample material; flow chamber to left.
FIG. 13 ASTM Permeation Test CellStandard Cell Configured for Liquid Challenges
NOTE 1—In each image, the closed chamber is on the right and the flow chamber is on the left of the assembly.
FIG. 2 Alternative Permeation Test Cell DesignTest Cell Setup—(a) 1 in. Diameter Cell; (b) 2 in. Diameter Cell
3.1.6 degradation, n—a deleterious change in one or more properties of a material.
3.1.6.1 Discussion—
For protective clothing materials, changes in physical properties are typically of most interest.
3.1.7 minimum detectable mass permeated, n—the smallest mass of test chemical that is detectable with the complete permeation
test system.
F739 − 20
FIG. 34 Example Set-upSetup for Continuous Collecting Medium Sample Withdrawal, Analysis, and Return
FIG. 45 Example Set-upSetup for Continuous Flow of Fresh Collecting Medium
3.1.7.1 Discussion—
This value is not necessarily the sensitivity of the analytical instrument.
3.1.8 minimum detectable permeation rate, n—the lowest rate of permeation that is measurable with the complete permeation test
system.
3.1.8.1 Discussion—
This value is not necessarily the sensitivity of the analytical instrument.
3.1.9 normalized breakthrough time, n—the time at which the permeation rate reaches 1.0 μg ⁄cm /min.
3.1.10 open loop, open-loop, adj—refers to a testing mode in which fresh collection medium flows continuously through the
collection chamber of the test cell.
3.1.11 penetration, n—for chemical protective clothing, the movement of substances through voids in protective clothing materials
or items on a non-molecular level.
3.1.11.1 Discussion—
Voids include gaps, pores, holes, and imperfections in closures, seams, interfaces, and protective clothing materials. Penetration
does not require a change if state; solid chemicals move through voids in materials as solids, liquids as liquids, and gases as gases.
Penetration is a distinctly different mechanism from permeation.
F739 − 20
NOTE 1—Fig. 56 shows five types of permeation behavior. Type A, the most typical, where the permeation rate stabilizes at a “steady state” value. Type
B behavior is due to the material specimen being structurally modified by the chemical, resulting in an increase or decrease in permeation rate. Type C
behavior occurs when the material specimen exhibits a sudden, very large increase in rate. Type D response happens when there is moderate to heavy
swelling of the material specimen, although the permeation rate eventually stabilizes. Type E response can occur when there is a high degree of swelling.
(Reprinted with permission by American Industrial Hygiene Association Journal Vol 42, 1981, pp. 217–225.)
FIG. 56 Five Types of Permeation Behavior
3.1.12 permeation, n—for chemical protective clothing, the movements of chemicals as molecules through protective clothing
materials by the processes of (1) absorption of the chemical into the contact surface of the materials, (2) diffusion of the absorbed
molecules throughout the material, and (3) desorption of the chemical from the opposite surface of the material.
3.1.12.1 Discussion—
Permeation is a distinctly different mechanism from penetration.
3.1.13 protective clothing, n—item of clothing that is specifically designed and constructed for the intended purpose of isolating
all or part of the body from a potential hazard; or, isolating the external environment from contamination by the wearer of the
clothing.
3.1.14 seam, n—a line along which two pieces of material are joined together in protective clothing.
F739 − 20
FIG. 61 The Breakthrough Detection Time for a method sensitivityMethod Sensitivity of 0.05 μg/cm /min is 23 minutes.25 min. The
Standardized Breakthrough Detection Time is 33 minutes.min. The Steady State Steady-State Permeation Rate is approximatelyAp-
proximately 0.15 μg/cm /min.
3.1.14.1 Discussion—
Common ways that seams are constructed include sewing with thread, welding with heat, taping, and gluing.
3.1.15 standardized breakthrough time, n—the time at which the permeation rate reaches 0.1 μg/cm /min.
3.1.16 steady-state permeation, n—the constant rate of permeation that occurs after breakthrough when the chemical contact is
continuous and all forces affecting permeation have reached equilibrium.
3.1.17 test chemical, n—the solid, liquid, gas, or mixture thereof, used to evaluate the performance of a protective clothing
material.
3.1.17.1 Discussion—
The liquid or gas may be either one component (for example, a neat liquid or gas) or have several components (for example, a
mixture).
3.1.18 volatile liquid, n—a liquid with a vapor pressure greater than 1 mm Hg at 25 °C.
3.2 For other protective clothing definitions, refer to Terminology F1494.
4. Summary of Test Method
4.1 The permeation of chemical(s) through a protective clothing material is assessed by measuring the breakthrough detection
time, standardized breakthrough time, normalized breakthrough time, subsequent permeation rate, and cumulative permeation over
a period of time through replicate specimens of the material.
4.2 In the permeation test apparatus, the protective clothing material specimen partitions the test chemical from the collection
medium.
4.2.1 The collection medium is analyzed quantitatively for its concentration of the test chemical and therebyand, thereby, the
amount of that chemical that has permeated the barrier as a function of time after its initial contact with the material.
4.2.2 By either graphical representation, appropriate calculations, or both, the breakthrough detection time, standardized
breakthrough time, and the permeation rate normalized breakthrough time, permeation rate, and cumulative permeation of the test
chemical are determined.
F739 − 20
5. Significance and Use
5.1 This test method is normally used to evaluate flat specimens from finished items of protective clothing and from materials that
are candidates for items of protective clothing.
5.1.1 Finished items of protective clothing include gloves, arm shields, sleeves, aprons, suits, hats, coveralls, hoods, boots,
respirators, and the like.
5.1.2 The phrase “specimens from finished items” encompasses seamed or other discontinuous regions as well as the usual
continuous regions of protective clothing items.
5.1.3 Selected seams for testing are representative of seams used in the principal construction of the protective clothing item and
typically include seams of both the base material and where the base material is joined with other types of materials.
5.2 The breakthrough detection time, standardized breakthrough time, permeation rate, and cumulative permeation are key
measures of the effectiveness of a clothing material as a barrier to the test chemical. Such information is used in the comparison
of clothing materials during the process of selecting clothing for protection from hazardous chemicals. Long breakthrough
detection times, long standardized breakthrough detection times, low amounts of cumulative permeation, and low permeation rates
are characteristics of better barriers.more effective barrier materials than materials with higher permeation characteristics.
NOTE 1—At present, only limited quantitative information exists about acceptable levels of dermal contact with most chemicals. Therefore, the data
obtained using this test method cannot be used to infer safe exposure levels.
5.2.1 The reporting of a standardized breakthrough time greater than a specific time period means that the test chemical has not
permeated the specimen at a rate exceeding 0.1 0.1 μg μg/cm⁄cm /min in the designated time. Permeation may or may not have
occurred at a lower rate during this time interval.
5.2.2 The reporting of cumulative permeation over a specified test period is another means to report barrier performance of
protective clothing for resistance to permeation. This measurement quantifies the total amount of chemical that passed through a
known area of the material during the specified test period.
NOTE 2—It is possible to relate cumulative permeation test results to the total amount of chemical to which an individual wearer may be exposed by
accounting for the exposed surface area and the underlying air layer. This information has value when there are known maximum permitted skin exposure
doses for specific chemicals.
5.3 The sensitivity of the test method in detecting low permeation rates or amounts of the test chemical that permeate is determined
by the combination of the analytical technique and collection system selected, and the ratio of material specimen area to collection
medium volume or flow rate.
5.3.1 The analytical technique employed shouldshall be capable of measuring the concentration of the test chemical in the
collection medium at,at or below, levelsbelow 0.05 μg ⁄cm consistent with the standardized breakthrough time value specified in
/min, 3.1.13and at,at or above,above the steady-state permeation rate.
5.3.2 Often permeation tests will require measurement of the test chemical over several orders of magnitude in concentration,
requiring adjustments in either the sample collection volume or concentration/dilution, or the analytical instrument settings over
the course of the test.
5.3.3 Higher ratios of material specimen area to collection medium volume or flow rate permit earlier detection of breakthrough
and detection of lower permeation rates and levels of cumulative permeation because higher concentrations of the test chemical
in the collection medium will develop in a given time period, relative to those that would occur at lower ratios.
5.4 Comparison of results requires specific information on the test cell, procedures, and analytical techniques. Results obtained
from closed-loop and open-loop testing may not be directly comparable.
5.4.1 The sensitivity of an open-loop system is characterized by its minimum detectable permeation rate. A method for
determining this value is presented in Appendix X1.
F739 − 20
5.4.2 The sensitivity of a closed-loop system is characterized by its minimum detectable mass permeated.
5.5 A group of chemicals for use in permeation testing is given in Guide F1001.
5.6 These test procedures are also a part of ISO 6529. ISO 6529 provides a harmonized standard that also permitsWhile this
method specifies standardized breakthrough time as the time at which the permeation rate reaches 0.1 μg ⁄cm using some practices
commonly followed in Europe for permeation testing, for example, using a breakthrough time normalized /min, it is acceptable
to continue the testing and also report a normalized breakthrough time at a permeation rate of 1.0 1.0 μg μg/cm⁄cm /min instead
of 0.1μg/cm/min. /min as used in this method. For this reason, the reporting of all permeation data must include the method that
is used in the testing. Guide F1194 provides guidance on reporting permeation test results.
5.7 It is recommended that the test be continued for the measurement of maximum or steady-state permeation rate or for the
duration specified for the determination of cumulative permeation.
5.7.1 It is permitted to terminate tests early if there is catastrophic permeation of the chemical through the protective clothing
material and the rate of permeation could overwhelm the capability of the selected analytical technique.
5.8 Guide F1194 provides a recommended approach for reporting permeation test results.
6. Apparatus
6.1 Thickness Gauge, suitable for measuring thicknesses to the nearest 0.02 mm (or the nearest 0.001 in.), as specified in Test
Method D1777, shall be used to determine the thickness of each protective clothing material specimen tested.
6.2 Analytical Balance, readable and reproducible to 60.5 mg, 60.5 mg, shall be used to determine weight per unit area of each
test specimen.
6.3 Test Cell, Cell—theThe test apparatus consists of a two-chambered cell for contacting the specimen with the test chemical on
the specimen’s normally outside surface and with a collection medium on the specimen’s normally inside surface. See Fig. 2.
NOTE 3—Use of a 2 in. (50 mm) diameter cell (Fig. 2(b)) is preferred over a 1 in. (25 mm) diameter cell (Fig. 2(a)) due to higher ratios of material
specimen surface area to collection medium volume.
6.3.1 Liquid Test Chemical, for liquid chemicals, the test cell,The chambers are shown in Fig. 1, is constructed of two sections
of straight glass pipe, each nominally sized to a 25.4-mm (1.0-in.) diameter.of two types: Materials other than glass may be used.
Such materials would be required for tests involving chemicals (for example, hydrofluoric acid) which are incompatible with glass.
The section that is designated to contain the test chemical is 25.4 mm (1.0 in.) in length. The second section, which is designated
to contain the collection medium, is 32 mm (1.2 in.) or less in length.
6.3.1.1 Closed Chamber—The closed chamber contains a fixed volume of liquid and a straight bore, standard taper spout for
adding challenge chemical or collection medium. Small volumes of collection medium may be removed with or without
replacement for analysis. The 1 in. closed chamber is 23 mm (0.917 in.) in length and 25.3 mm (1.0 in.) internal diameter (see
Fig. 2(a)). The internal volume of the closed chamber is 17.1 mL. The 2 in. closed chamber is 22.0 mm (0.87 in.) in length and
50 mm (2.0 in.) internal diameter (see Fig. 2(b)). The internal volume of the closed chamber is 48 mL.
6.3.1.2 Flow Chamber—The flow chamber has inlet and outlet ports with valves through which a challenge chemical or a
collection medium flows during the test. The flow chamber is used for continuously passing a gaseous challenge over the normally
outside surface of the test specimen, or continuously passing a gaseous or liquid collection medium over the normally inside
surface of the test specimen. The 1 in. flow chamber is 31 mm (1.25 in.) in length and 25.3 mm (1.0 in.) internal diameter. The
inlet and outlet ports have 4 mm (0.19 in.) internal diameters (see Fig. 2(a)). The internal volume of the flow chamber is 17.8 mL.
The 2 in. flow chamber is 35 mm (1.38 in.) in length and 50 mm (2.0 in.) internal diameter. The inlet and outlet ports have 4 mm
(0.16 in.) internal diameters (see Fig. 2(b)). The internal volume of the flow chamber is 68.7 mL.
6.3.1.3 The open open, circular end of each chamber is flared to create a flange that facilitates clamping the chambers together.
F739 − 20
6.3.1.4 Inlet and outlet ports, with stopcock valves, if desired, are added to each chamber to enable the introduction and
withdrawal of test chemical and collection medium, if appropriate. The collection medium inlet tube should direct the collection
medium directly towards the center of the clothing material specimen. The inside diameter of tubing, ports, stopcocks, etc. should
be at least 2 mm (0.08 in.) to prevent undesirable pressure differences in the system.Use chemically inert and non-absorptive test
cell parts that contact the test chemical.
NOTE 4—The standard closed and flow chambers are made of glass. Test chemicals (for example, hydrofluoric acid) that are corrosive to glass require
chambers constructed of alternative materials.
6.3.1.3 Each chamber may also be equipped with a straight bore, standard taper spout. This spout may be useful for adding and
removing test chemical and collection medium. The spouts may also be used to introduce stirrers into the chambers.
6.3.1.4 Upon assembly, the clothing material is clamped between the two chambers by means of a yoke having at least three bolts.
Two PTFE gaskets having smooth, rounded edges are used at the joint, with the clothing material between them.
6.3.2 Select the test cell configuration based on the challenge chemical and most appropriate analytical method.
NOTE 5—The configuration can be of two closed chambers, two flow chambers, or one closed and one flow chamber.
6.3.2.1 When the flow chamber contains the challenge chemical, the chemical is introduced through the longer stem that goes all
the way to the end of the chamber. A shorter stem on the side of the test chamber provides the challenge chemical a means of exit
from the test chamber. This mode of entry and exit of the challenge chemical aids in mixing of the chemical inside the test chamber.
Flow of the challenge chemical must be regulated such that its composition and the concentration does not change over time.
6.3.3 The test specimen is sandwiched between two PTFE or butyl gaskets and the assembly is clamped between the two
chambers.
NOTE 6—Butyl gaskets can become contaminated and contaminate future tests.
NOTE 7—Adequate seal of elastomeric specimens may be achieved without use of gaskets.
6.3.4 Discussion—Additional Information: The bolts shall be tightened with sufficient torque to prevent leakage of the test
chemical or the collection medium but avoid damage to the clothing material or the test cell.
6.3.4.1 Leak-tight Make leak-tight connections to the collection chamber inlet and outlet tube must be made. tube. In addition,
all tubing coming into use tubing which is in contact with the test chemical should bethat is made from material that does not
absorb or react with the test chemical. Glass, PTFE, or stainless steel can be usedare appropriate choices in most cases.
Connections It is recommended to make connections of external tubing to the glass inlet and outlet ports of the test cell chambers
can be made via PTFE pressure-fit union connectors.
6.3.4.2 In non-flow tests where increased analytical sensitivity is required, use a closed chamber to reduce the volume of the
collection medium. This increases the sensitivity of the method by increasing the ratio of material specimen area to the collection
medium volume. Similarly, use a lower volume test chamber for a high hazardous chemical to minimize the amount of chemical
being used for testing
6.3.4.3 In closed-loop tests where increased analytical sensitivity is required, a shorter length chamber may be used to reduce the
volume of the collection medium. This increases the sensitivity of the method by increasing the ratio of material specimen area
to the collection medium volume. In open-loop tests, lower collection medium flow rates will increase the system sensitivity by
lowering the minimum detectable permeation rate. However, these approaches to increasing sensitivity must be achieved within
the constraints of having sufficient volumes and mixing rates so as not to interfere with the permeation process.
NOTE 8—A flow rate of 0.1 L ⁄min has been found to achieve the required analytical sensitivity for minimum detectable permeation rate with an optimal
mixing efficiency.
The test cell as shown isclosed and flow chambers are available from Pesce Lab Sales, P.O. Box 235, 226 Birch St., 355 N. Lincoln St, Kennett Square, PA 19348.
F739 − 20
6.3.2.3 Liquid test chemicals that are mixtures must be stirred to minimize concentration gradients. Stirring may be effected by
a stirring rod inserted through the fill spout or a magnetic stirrer. If there is not a good seal of the shaft of the rod and the spout,
evaporation of the chemical can occur, reducing its volume and potentially changing its composition.
6.3.2.4 For a liquid collection medium that is not circulated, the two chambers of the test cell must permit the mixing, withdrawal
and replenishment of the collection medium during the test.
6.3.5 For gaseous test chemicals, the test cell can consist of two chambers one of which allows the gaseous test chemical to be
circulated from its reservoir. Flow must be such that the composition and concentration of the gas in the test chamber does not
change with time, and the test gas in the chamber is well mixed.Special considerations with liquids that are mixtures:
6.3.5.1 In case of liquids that are mixtures and for liquid collections, minimize concentration gradients by mounting the test cell
setup on a rocker table in a vertical orientation to ensure both surfaces of the specimen are fully contacted by liquids. Set the table
rocker to be continuous with lowest speed sufficient to promote uniform mixing.
6.3.5.2 Alternatively, liquid test chemicals that are mixtures can be stirred to minimize concentration gradients. Use a stirring rod
inserted through the fill spout or a magnetic stirrer.
6.3.5.3 If a stirrer is used, do not let it contact or damage the specimen.
NOTE 9—If there is a poor seal of the shaft of the rod with the spout, evaporation of the chemical can occur, reducing its volume and potentially changing
its composition.
6.3.5.4 For a liquid collection medium that is not circulated, use a test cell design and permeation test setup that permits the
mixing, withdrawal, and replenishment of the collection medium during the test.
6.4 Alternative Test Cell—Cells—Alternative permeation test cells may be shall be permitted to be used, provided that the results
are the type of test cell used is reported as prescribed in Section 12. The cellscell and configuration described above and shown
in Fig. 1Figs. 2 and 3, however, areis the standards.standard. If a differentan alternate cell is used, it the equivalence of the
alternative test cell must be documented as described in Section 12. An alternative design that has been documented is shown in
Fig. 2.
6.5 Constant Temperature Constant-Temperature Chamber or Bath, used to maintain the test cell within 61.0°C61.0 °C of the
test temperature. The standard temperature for this test is 27°C.is 27 °C. Condition all test materials, including the test cells and
chemicals, in the chamber(s) ofor bath(s) prior to testing.
6.6 Circulating Pump, if appropriate, is used to transport the collection medium,medium or test chemical, or both, through the test
cell. All parts contacting the test chemical or fluid containing it must be chemically inert and non-absorptive to the test chemical.
The flow rate must be sufficiently high to provide adequate mixing,mixing or dilution, or both, within the test cell.
NOTE 10—If a circulating pump is used, care should be taken to avoid inducing pressure which may deform or damage the test specimen.
6.7 Flow Meter, used to measure the flow rate of the collection medium through the collection chamber. A calibrated rotameter,
or similarly accurate device, mayshall be used. The flow rate shall be measured in-line with all system components in place at the
start of each test.
6.8 Thermometer or Thermocouple, used to measure the temperature of the constant-temperature chamber (or bath), or the
collection chamber of the test cell, or both. A calibrated device,device accurate to 60.5°C must60.5 °C shall be used.
7. Safety Precautions
7.1 Before this test method is carried out, safety precautions recommended for handling any potentially hazardous chemical should
be identified and reviewed to provide full protection to all personnel.
F739 − 20
7.1.1 For carcinogenic, mutagenic, teratogenic, and other toxic (poisonous) chemicals, the work area should be isolated,
well-ventilated, well ventilated, and meticulously clean. Involved personnel should be outfitted with protective clothing and
equipment.
7.1.2 For corrosive or otherwise hazardous chemicals, involved personnel should, as a minimum, should be outfitted with
protective clothing and equipment.
7.2 Emergency equipment, such as a safety shower, eye wash, and self-contained breathing apparatus, should be readily accessible
from the test area.
7.3 Appropriate procedures for the disposal of the chemicals should be followed.
8. Testing and Analytical Technique Consideration
8.1 Each protective clothing material specimen may shall be permitted to consist of either a single layer or a composite of multiple
layers that is representative of an actual protective clothing construction, with all layers arranged in proper order. In each test, the
specimen’s normally outer surface shall contact the test chemical.
8.1.1 If,If in a proposed design of an item of protective clothing,protective clothing different materials or thicknesses of materials
are specified at different locations, specimens from each location shall be tested.
8.1.2 If,If in a proposed design, design of protective clothing seams are specified,used, additional specimens containing such
seams shall be tested. Care must be taken to ensure that the test cell can be properly sealed when specimens of nonuniform
thickness are tested.
NOTE 11—Use of a 2 in. (50 mm) diameter cell is preferred over a 1 in. (25 mm) diameter cell for this reason.
8.2 Each material specimen to be tested shall have a minimum cross dimension of 43 mm (1.7 in.). A 51-mm (2-in.) diameter circle
is convenient.Sample size is dependent on test cell dimensions.
8.2.1 For a 2 in. (50 mm) diameter cell, each material specimen to be tested shall have a minimum cross dimension of 68.6 mm
(2.7 in.). A 76.2 mm (3 in.) diameter circle is convenient.
8.2.2 For a 1 in. (25 mm) diameter cell, each material specimen to be tested shall have a minimum cross dimension of 43 mm
(1.7 in.). A 51 mm (2 in.) diameter circle is convenient.
8.2.3 Specimens are permitted to extend beyond the edge of the sealing surface if the larger specimen does not interfere with the
ability to seal the test cell.
8.3 A minimum of three random specimens shall be tested. Random specimens shall be generated as described in Practice E105.
8.4 To avoid incidental contamination of exposed surfaces, clean gloves mayshall be worn when handling specimens.
8.5 To avoid affecting permeation measurements, aquantification, the collection medium should not interact with the test
material,material and must have adequate capacity for the permeant. To have adequate capacity for the permeant, the collection
medium should not exceed 20%20 % of its saturation concentration from the permeant at any time during the test. For a liquid
collection medium, saturation is the maximum solubility or miscibility of the permeant in the liquid at the test temperature. For
a gaseous collection medium, saturation is determined by the vapor pressure of the permeant.
8.6 Under conditions in which the test chamber or bath is at a temperature significantly different from that of the test chemical
or collection medium that is being introduced into the test cell, the temperature in the test chemical chamber and/oror the collection
chamber chamber, or both, should be measured. It may be necessary to pre-conditionprecondition the test chemical or collection
medium before it enters into the test cell. Similarly, it may be necessary to maintain the temperature of the collection medium after
it leaves the test cell to prevent condensation or precipitation.
F739 − 20
8.7 The combination of system configuration, analytical technique, and collection medium shall be selected to allow
measurementquantification of the test chemical over the range of concentrations that is consistent with 5.3.1, without exceeding
the maximum concentration limits within the system as defined in 8.5.
8.7.1 The combination of system configuration, analytical technique, and collection medium shall be calibrated with the test
chemical over the range of permeant concentrations consistent with 8.7.
8.7.2 Distilled water is preferred as a collection medium for non-volatile and semi-volatile test chemicals and non-water sensitive
protective clothing materials. Consider alternative liquids only when the test chemical does not meet the solubility requirements
as described in 8.5. or when the protective clothing material is water sensitive.
8.7.3 Air, nitrogen, and helium are the preferred choices for the collection medium for volatile test chemicals. Consider alternative
gases only when these gases interfere with analytical detection of the test chemical. Regardless of the gas used, its purity must be
sufficiently high so as not to interfere with the permeation process or the analytical procedure.
8.7.4 In open-loop testing, the system shall have a sensitivity of at least 0.1μg/cm0.05 μg ⁄cm /min. (See Appendix X1.)
8.7.5 In closed-loop testing, the system shall have a minimum sensitivity to detect a permeation rate of 0.1μg/cm0.05 μg ⁄cm /min
over a five minute 5-min sampling period.
8.8 With the nominal 25 mm diameter cell and in open-loop mode or in closed-loop mode with a circulating collection medium,
the minimum flow rate for the collection medium is 100 cm /min. Higher flow rates are preferred within the constraints imposed
by analytical sensitivity, temperature control, and pressure gradients in the system.
8.9 With the nominal 2550 mm diameter cell and in open-loop mode or in closed-loop mode with a circulating collection medium,
the minimum flow rate for the collection medium is 100 cmflow rate is 300 cm /min. Higher flow rates are preferred within the
constraints imposed by analytical sensitivity, temperature control, and pressure gradients in the system. (A minimum collection
medium flow rate of 300 cm /min is required for a nominal 50-mm diameter cell.)
8.9.1 The purpose of agitating/mixing the collection medium is twofold: to ensure that it is homogeneous for sampling and
analytical purpose and to prevent or minimize concentration boundary layers of permeant at the interface of the clothing material
and the collection medium. The degree of agitation necessary to achieve these objectives is dependent on the permeation rate and
the relative solubilities of the test chemical in the clothing material and the collection medium. At this time, sufficient data are not
available to specify minimum agitation rates. However, as guidance, in any system in which the collection medium is flowing
through the collection chamber, the minimum flow rate should be five chamber volumes per minute. Higher rates may be required
for permeants with low solubilities in the collection medium or high permeation rates. High flow rates also result in better mixing
in the chamber and consequentlyand, consequently, more uniform samples for analysis. For these reasons, it is recommended that
the condition of steady-state permeation be verified by measuring it at two different flow rates (see 10.9). Note, however, that
higher flow rates will reduce the sensitivity of the system to the detection of breakthrough. For non-circulating collection medium
systems, adequate mixing levels can be determined by preliminary experiments in which the rapidity of the dispersion of a dye
is observed.
8.10 Care must be taken so as not to pressurize the test or collection chambers. Overly high pressures may develop at high gas
flow rates or as a result of attachments that restrict the flow of gas from the chamber. Tightly-packed Tightly packed activated
carbon beds or highly restrictive sparger tubes are examples of such attachments. A differential pressure gauge can be used to
measure pressures within the test or collection chamber over the range of expected flow rates by use of a modified chamber having
an access port. As a rule of thumb, internal pressures should not exceed ambient pressure by more than 5 %. Over-
pressurizationOverpressurization of either chamber of the test cells may resultsresult in distortion of the specimen, with concurrent
increase in specimen surface area and decrease in specimen thickness.
8.11 In closed-loop systems with sample withdrawal, replenishment of the collection medium may be necessary to maintain a fixed
ratio of collection medium volume to surface area of the test specimen in contact with the collection medium. See 11.4 for
calculations related to this issue.
F739 − 20
8.12 In cases where samples are withdrawn, analyzed, and returned to the test cell, no provision for volume maintenance is
necessary.
9. Conditioning
9.1 Condition each protective clothing material specimen for a minimum of 24 h by exposure to a temperature of 27 6 2°C
(81 6 4°F)27 6 2 °C (81 6 4 °F) and a relative humidity of 30 to 80 % as described in SpecificationPractice E171E171/E171M.
9.2 Different types of specimen preconditions are permitted, including repeated flexing or abrasion, on samples from which
permeation test specimens are removed. Describe any specific preconditions used in the test report.
10. Procedure
10.1 Measure the thickness of each conditioned specimen to the nearest 0.02 mm (or nearest 0.001 in.) at three locations within
the area of the specimen that is to be exposed to the test chemical. Calculate the average thickness and record.
10.2 Determine specimen weight per unit area,area in grams per square centimetrecentimeter by weighing the specimen on an
analytical balance (62 mg) and dividing by the area (60.4 cm ), and record. This value, along with thickness, is a key
characteristic of the material and is needed when comparing the results of permeation testing.
10.3 Measure and record the inside diameter of the nominal 25-mm 25 mm diameter opening of the PTFE gasket. Mount the first
specimen in the test cell and assemble as shown in Fig. 1Figs. 2 and 3 and described in 6.3.1 and 6.3.3.
10.3.1 Seal the test specimen in the test cell to prevent leakage but to avoid damage to the test specimen.
10.3.2 Special gasket materials are generally needed to seal specimens with uneven surfaces such as seams, which join two
materials.
10.4 Place the assembled test cell into a constant-temperature chamber or bath at 27°C,27 °C, the standard temperature for this
method. Other temperatures may be used,used but must be noted in the report. The test cell must not be removed from the
temperature chamber or bath for the duration of the test.
10.5 Charge the collection medium into the test-cell chamber to which the normally test cell chamber that contacts the inside
surface of the material specimen is exposed. specimen. The collection medium must be at the test temperature when it is
introduced. Depending upon the combination of analytical technique and collection medium selected, attach peripheral devices as
appropriate (see Figs. 34 and 45). The cell, along with the collection medium, should be maintained at the test temperature for at
least 30 minutes 30 min before the test proceeds further. Temperature variances have significant effects on the results and
reproducibility of the method.
10.6 Stir, circulate, or flow the collection medium continuously. (See Discussion following 8.88.9.1.)
10.7 Initiate sampling of the collection medium, either continuously or discretely, and continue on a predetermined schedule
throughout the test duration. Promptly complete analysis of each sample for test chemical content. Sampling is initiated before the
test chemical is added to the test cell to establish the baseline values against which subsequent analytical data will be compared.
(See Note 2.)
NOTE 12—The method chosen for collection medium withdrawal shall be based on the technique selected for analytical detection. For example, UV or
IR spectroscopy is often used for continuous analysis of a sample stream (although compounding and curing agents often used in protective clothing
materials can interfere)interfere), while gas chromatography requires the analysis of discrete samples. When sampling using open-loop techniques, the
flow of collection medium should never be interrupted. This will minimize adsorption of permeated test chemical on the walls of the test cell and
associated tubing.
10.8 Add the test chemical into the test chemical chamber.
F739 − 20
10.8.1 For liquid test chemicals, the chemical can be introduced by pouring, syringe, cannula, etc. Fill the chamber to a level that
indicates the liquid is covering the clothing material specimen, with no air bubbles. Begin timing the test when the addition of the
liquid commences.
10.8.2 For gaseous test chemicals, begin the flow of the gas into the test chemical chamber. Begin timing the test when the
equivalent of five chamber volumes of gas have passed through the chamber as determined by means of a rotameter or other flow
monitoring flow-monitoring device placed in the outlet stream of the test chemical chamber.
10.9 Record the concentration of the test chemical found in each sample and the associated time that has elapsed between the time
that the challenge chemical was charged to the cell and the withdrawal of the sample.
10.9.1 An analytical sample should be collected as soon as possible after contact of the specimen with the test chemical, but must
be collected within the first 15 minutesmin of contact.
10.10 Discontinue sampling and terminate the test after o
...