ASTM F3136-22

Standard Test Method for Oxygen Gas Transmission Rate through Plastic Film and Sheeting using a Dynamic Accumulation Method

SIGNIFICANCE AND USE
5.1 The Oxygen Transmission Rate is an important determinant of packaging functionality afforded by packaging materials for a wide variety of packaged products including food, pharmaceuticals and medical devices. In some applications, sufficient oxygen must be allowed to permeate into the package. In others, the oxygen ingress must be minimized to maintain product quality.  
5.2 Other ASTM Standard Methods to measure the oxygen transmission rate are described in Test Method D3985 and Test Method F2622.
SCOPE
1.1 This test method covers a procedure for determination of the transmission rate of oxygen gas through plastics in the form of film, sheeting, laminates, coextrusions, coated or uncoated papers or fabrics.  
1.2 This test method is not the only method for measurement of the oxygen transmission rate (OTR). There are other methods of OTR determination that use other oxygen sensors and procedures.  
1.3 The values stated in SI units are to be regarded as standard. Commonly used metric units used to report Oxygen Transmission Rate are included in Terminology, Procedure, Precision and Bias sections and in the Calculation section of the Appendix.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
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.

General Information

• Status: Published
• Publication Date: 30-Nov-2022
• ICS: 75.180.30 - Volumetric equipment and measurements
• Technical Committee: F02 - Primary Barrier Packaging
• Drafting Committee: F02.10 - Permeation

Relations

• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM F2622-08(2013) - Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
• Effective Date: 01-Oct-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM D3985-05(2010)e1 - Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor
• Effective Date: 01-Oct-2010
• Refers: ASTM E177-10 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2010
• Refers: ASTM E177-08 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2008
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM F2714-08 - Standard Test Method for Oxygen Headspace Analysis of Packages Using Fluorescent Decay
• Effective Date: 01-Aug-2008
• Refers: ASTM F2622-08e1 - Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
• Effective Date: 01-Apr-2008
• Refers: ASTM F2622-08 - Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
• Effective Date: 01-Apr-2008
• Refers: ASTM E177-06b - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 15-Nov-2006
• Refers: ASTM E177-06a - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2006
• Refers: ASTM E691-05 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2005

Overview

ASTM F3136-22 is a widely recognized standard developed by ASTM International that provides a test method for determining the oxygen gas transmission rate (OTR) through plastic film and sheeting using a dynamic accumulation method. This standard is essential for evaluating the barrier properties of packaging materials used in industries such as food, pharmaceuticals, and medical devices, where the management of oxygen ingress is vital for product quality and shelf life.

Unlike other techniques, the dynamic accumulation method quantitatively measures the oxygen permeation across plastic films, laminates, coextrusions, coated or uncoated papers, and fabrics. It provides consistency and reproducibility, enabling manufacturers and researchers to benchmark packaging performance effectively.

Key Topics

• Oxygen Transmission Rate (OTR): OTR denotes the quantity of oxygen gas passing through a unit area of plastic film per unit of time under specified conditions. It is a crucial parameter for assessing the functional barrier properties of packaging materials.
• Dynamic Accumulation Method: This method involves mounting the film sample as a semi-barrier between two chambers in a permeation apparatus. A stream of nitrogen purges the sensing well, while a gas with a known oxygen concentration is introduced into the driving well. Oxygen accumulation in the sensing well is periodically measured, and OTR is calculated based on changes in concentration over time.
• Test Conditions: The standard emphasizes the importance of controlling variables such as temperature, humidity, and partial pressure of oxygen to ensure accurate and reproducible results.
• Calibration and Measurement: Fluorescence-based oxygen sensors are calibrated using gases with known oxygen concentrations. The test relies on monitoring fluorescence decay, which corresponds to oxygen concentration changes in the sensing well.

Applications

The ASTM F3136-22 standard is used across various industries to:

• Food Packaging: Assessing the capability of multilayer plastic films to minimize oxygen ingress and thereby extend product freshness and shelf life.
• Pharmaceutical and Medical Packaging: Evaluating barrier materials to ensure product efficacy by limiting oxygen exposure, which can affect sensitive drugs and medical devices.
• Material Development: Comparing new packaging materials, coatings, and laminates based on their oxygen barrier performance for optimized functionality.
• Quality Control: Routine monitoring of plastic film manufacturing to maintain consistent quality and compliance with regulatory requirements.

Organizations use this standardized method to determine if packaging materials meet required OTR specifications, helping to reduce product spoilage and ensuring customer satisfaction.

Related Standards

Several other ASTM standards are referenced within ASTM F3136-22 for measuring OTR and for supporting terminology and practices:

• ASTM D3985: Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor.
• ASTM F2622: Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors.
• ASTM F2714: Test Method for Oxygen Headspace Analysis of Packages Using Fluorescent Decay.
• ASTM E177 & E691: Standards for precision, bias, and interlaboratory studies relating to test methods.

ASTM F3136-22 aligns with internationally recognized guidelines for standardization and is compliant with principles established by the World Trade Organization Technical Barriers to Trade (TBT) Committee. Its application ensures consistency and transparency in measuring oxygen permeability, providing important technical assurance for global trade and quality assurance initiatives.

Keywords: oxygen transmission rate, OTR, ASTM F3136, plastic film permeability, barrier packaging, dynamic accumulation, packaging materials, food packaging standard, pharmaceutical packaging standard, oxygen permeation testing.

Standards Content (Sample)

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: F3136 − 22
Standard Test Method for
Oxygen Gas Transmission Rate through Plastic Film and
Sheeting using a Dynamic Accumulation Method
This standard is issued under the fixed designation F3136; 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 E177Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
1.1 This test method covers a procedure for determination
E691Practice for Conducting an Interlaboratory Study to
of the transmission rate of oxygen gas through plastics in the
Determine the Precision of a Test Method
form of film, sheeting, laminates, coextrusions, coated or
F2622Test Method for Oxygen Gas Transmission Rate
uncoated papers or fabrics.
Through Plastic Film and Sheeting UsingVarious Sensors
1.2 This test method is not the only method for measure-
F2714Test Method for Oxygen Headspace Analysis of
ment of the oxygen transmission rate (OTR). There are other
Packages Using Fluorescent Decay
methods of OTR determination that use other oxygen sensors
and procedures.
3. Terminology
1.3 The values stated in SI units are to be regarded as
3.1 Definitions:
standard. Commonly used metric units used to report Oxygen
3.1.1 Oxygen Transmission Rate (OTR), n—the quantity of
Transmission Rate are included in Terminology, Procedure,
oxygen gas passing through a unit area of the parallel surfaces
Precision and Bias sections and in the Calculation section of
of a plastic film per unit time under the conditions of test. The
the Appendix.
SI unit of transmission rate is the mol/(m ·s). The test condi-
1.4 This standard does not purport to address all of the
tions including temperature, relative humidity and oxygen
safety concerns, if any, associated with its use. It is the
partial pressure on both sides of the film must be stated in the
responsibility of the user of this standard to establish appro-
report.
priate safety, health, and environmental practices and deter-
3.1.1.1 Discussion—A commonly used unit of OTR is the
mine the applicability of regulatory limitations prior to use.
3 2
cm (STP)/(m ·day) at one atmosphere pressure difference
1.5 This international standard was developed in accor-
where 1 cm (STP) is 44.62 µmol, 1 atmosphere is 0.1013
dance with internationally recognized principles on standard-
MPa, and one day is 86.4 × 10 s. The OTR in SI units is
ization established in the Decision on Principles for the
obtained by multiplying the value in commonly used units by
Development of International Standards, Guides and Recom-
-10
5.160 × 10 .
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 The specimen is mounted as a sealed semi-barrier
2.1 ASTM Standards:
between two chambers, which together make up the perme-
D3985Test Method for Oxygen Gas Transmission Rate
ation apparatus. The sensing well which contains the oxygen
Through Plastic Film and Sheeting Using a Coulometric
sensor is slowly purged by a stream of pure nitrogen or other
Sensor
oxygen deficient gas mixture until the oxygen concentration
represents that of the purge gas. A commercial grade of
compressed nitrogen containing less than 0.05% oxygen is
ThistestmethodisunderthejurisdictionofASTMCommitteeF02onPrimary recommended.Agasofknownoxygenconcentration,typically
Barrier Packaging and is the direct responsibility of Subcommittee F02.10 on
air or pure oxygen, is directed into the opposite chamber, the
Permeation.
driving well. Oxygen concentration in the sensing well con-
Current edition approved Dec. 1, 2022. Published December 2022. Originally
taining the oxygen sensor is measured periodically and the
approved in 2015. Last previous edition approved in 2015 as F3136–15. DOI:
10.1520/F3136-22.
accumulating oxygen concentration recorded. The Oxygen
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Transmission Rate (OTR) parameter is determined from the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
slope of the logarithm of accumulated oxygen concentration in
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the sensing well versus time as described in 14.2.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3136 − 22
5. Significance and Use 7.1.1.3 The sensing well of the permeation apparatus shall
have a low-permeability window transparent to wavelengths
5.1 The Oxygen Transmission Rate is an important deter-
used to activate and read the oxygen sensor which is mounted
minant of packaging functionality afforded by packaging
within the sensing well.
materials for a wide variety of packaged products including
7.1.1.4 The oxygen sensor incorporates a fluorophore that
food, pharmaceuticals and medical devices. In some
fluoresces in response to a certain wavelength of light, but is
applications, sufficient oxygen must be allowed to permeate
quenched in the presence of oxygen. The oxygen quenching
into the package. In others, the oxygen ingress must be
effect is calibrated to oxygen concentration. This sensing
minimized to maintain product quality.
technology is identical to the sensing technology described in
5.2 OtherASTM Standard Methods to measure the oxygen
Test Method F2714.
transmissionratearedescribedinTestMethodD3985andTest
7.1.1.5 The permeability apparatus shall incorporated suit-
Method F2622.
able fittings for the introduction and exhaust of gases without
significant loss or leakage.
6. Interferences
7.2 It is necessary to control the temperature of the perme-
6.1 Any leakage within the permeation apparatus or
ability apparatus during the test period. A simple heating/
mounted packaging film will affect results. A means to assess
cooling chamber regulated to 60.5°C, is adequate for this
leakage is described in 9.2.
purposeinwhichtheapparatusishousedduringthetestperiod.
6.2 The condition of the sample film must be noted such as
7.3 Flow meters having an operating range from 1cm /min
wrinkles or other defects can affect results.
to 100 cm /min are required to monitor the flow rate of the
nitrogen purge stream and, if used, the oxygen or compressed
7. Apparatus
air circulation stream. Sufficiently low flow rates and/or
7.1 Oxygen Gas Transmission Apparatus,asdiagrammedin
balanced pressures on each side of the film are required to
Fig. 1 with the following:
avoid stretching the specimen which would modify the effec-
7.1.1 Permeation Apparatus (diffusion cell) shall consist of
tive sensing well volume.
two metal halves, which, when closed upon the test specimen,
7.4 An external light source provides sufficient light in the
will define a known gas transmission area. The volume of the
appropriate wavelength to activate the oxygen sensor.
sensing well containing the oxygen sensor must be accurately
known.
7.5 A light detector, and associated electronics, determines
7.1.1.1 O-ring—A circular transmission area permits appli-
the fluorescence decay constant, which is proportional to
cation of a static O-ring in a properly constructed O-ring
oxygen concentration.
groove in the side of the permeation apparatus that does not
7.6 A computer is used to calculate the oxygen concentra-
contain the oxygen sensor. The test area of the sensing well is
tion at specified time intervals based on decay rates. The
considered to be that area established by the inside contact
oxygen transmission rate of the film is calculated from that
diameter of the compressed O-ring when the permeation
data.
apparatus is clamped shut. The area, A, can be obtained by
measuring the inside diameter of the imprint left by the O-ring
8. Reagents and Materials
onthespecimenafterithasbeenremovedfromthepermeation
apparatus. 8.1 Nitrogen enriched purge gas shall contain a known
7.1.1.2 The sensing well of the permeation apparatus shall concentration of nitrogen. Commercial grade compressed ni-
haveaflatraisedrim.Sincethisrimisacriticalsealingsurface trogen(<0.05%oxygen),certifiedpurenitrogengas,cryogeni-
against which the test specimen is pressed, it shall be smooth cally stored nitrogen or nitrogen enriched gas produced using
and flat without radial scratches. on-site generators may be used.
FIG. 1 A Practical Arrangement of Components for the Measurement of Oxygen Transmission Rate Using an Optical Florescent Oxygen
Sensor and a Permeation Apparatus
F3136 − 22
An example of a Permeation Apparatus (aka Diffusion Cell) is pictured (above).
FIG. 2 Permeation Apparatus as described in this method (film specimen is shown adhered to the sensing well)
8.2 Transmission gas shall be of a known oxygen concen- 10. Sampling
tration with an oxygen concentration at least 10% greater than
10.1 Film samples used for the determination of OTR shall
the purge gas. Typically, commercial grade compressed
be representative of materials for which the data are required.
oxygen,certifiedgasorairisused.Also,regulatedcompressed
Careshallbetakentoensurethatsamplesarerepresentativeof
air can be used or the driving well can simply be left open to
conditions across the width and along the length of a roll of
ambient air. When using ambient air as the test gas, it’s
film.
important to note the humidity of the air as some materials are
moisture sensitive and their measured oxygen transmission
11. Test Specimens
rates can change with varying humidity levels. Classic ex-
11.1 Test specimens shall be representative of the material
amples of these material include (but not limited to): Coated
and shall be free of defects including wrinkles, creases, and
Papers, polyimide and Ethylene Vinyl Alcohol copolymers
pinholes, unless these are characteristics of the material being
(EVOH).
tested and included in the material description.
8.3 Sealing Grease—High-viscosity silicone stop cock
11.2 Average thickness shall be determined 6 3 µm using a
grease or high-vacuum grease is required for sealing the
calibrateddialgage(orequivalent)ataminimumoffivepoints
specimen film in the diffusion cell.
distributed over the entire test area. Maximum, minimum, and
averagevaluesshallberecorded.Samplethicknessneednotbe
9. Precautions
measured for determination of sample OTR only.
9.1 Temperature is a critical parameter affecting the mea-
11.3 Ifthetestspecimenisofanasymmetricalconstruction,
surement of OTR. Careful temperature control can help to
the two surface shall be marked by appropriate distinguishing
minimize variations due to temperature fluctuations. During
marks and the orientation of the test specimen within the
testing,thetemperatureshallbemonitoredandcontrolledto 6
permeation apparatus shall be reported.
0.5°C. Temperature variations should be minimized. The
average temperature and a range of temperatures during a test
shall both be recorded. 12. Calibration
9.2 Oxygen that leaks into the sensing well through faulty 12.1 General Approach—The oxygen sensor fluoresces
valves, fittings, or through an improperly sealed window can when exposed to certain wavelengths of light. Oxygen
significantly affect the accuracy of the measurement. Periodic quenches the fluorescent decay response.The sensor apparatus
leak checks using impervious films such as metal foils with utilizes a light source to deliver light to the oxygen sensor
thicknesses ≥25 µm (with their expected permeations of zero) which, in turn, fluoresces. This light is measured by the
shouldbetakentoidentifysuspectedsystemleaks.Leakcheck detector. The detector determines the exponential fluorescent
permeation tests should be run at least every 3-6 months and response decay constant, which is calibrated to oxygen con-
each test should be run for a minimum of 12 hours. centration.
F3136 − 22
12.2 Calibration—The sensor system is calibrated by mea- stated previously, care must be taken to prevent any pressure
suringoxygenconcentrationattwoknownvalues,typicallyair differential on either side of the film specimen which may
(20.9%oxygen)andpurenitrogen(0%oxygen).Thesevalues distort it, changing the sensing well volume.
define a calibration curve from which unknown oxygen levels
13.3.3 Oxygen concentration in the sensing well is mea-
may be determined. Alternatively, 2 gases of known concen-
sured periodically at time increments sufficient to indicate a
trations nearer to the level under test may prove to yield a
small gain in oxygen with each reading (changes of 0.05%
better calibration value (perhaps 3% and 0% oxygen).
oxygen have been found satisfactory between readings).
13.3.4 The test should continue until such time as the
13. Procedure
experimenter is satisfied that the indicated increase in oxygen
13.1 Apply a thin layer of sealing grease (see 8.3) around
concentration during the test period is consistent with results
theraisedrimofthesensingwelloppositetheO-ring.Placethe
obtained from previous periods.
specimen on the greased surface, taking care to avoid wrinkles
13.4 Start/End Points—The permeation of the sample and
or creases. Close and secure the permeation apparatus.
the permeation precision sought will determine the oxygen
13.2 The system can be calibrated with the test specimen in
levelsatwhichtostartandendrecordingdata.Asguidance,the
place.
following table can be used.
13.2.1 Openboththeinletandoutletvalvesconnectedtothe
Barrier Level Range Start % End %
3 2 3
sensing well of the permeation apparatus. If using air as the
Medium 2 cm (STP)/(m ·day) to 100 cm (STP)/ 0.50 2.00
(m ·day)
upper oxygen level calibration gas, there is no need to purge
3 2
Poor greater than 100 cm (STP)/(m ·day) 1.00 3.00
thesensingwellasitalre
...

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: F3136 − 15 F3136 − 22
Standard Test Method for
Oxygen Gas Transmission Rate through Plastic Film and
Sheeting using a Dynamic Accumulation Method
This standard is issued under the fixed designation F3136; 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.
1. Scope
1.1 This test method covers a procedure for determination of the transmission rate of oxygen gas through plastics in the form of
film, sheeting, laminates, coextrusions, coated or uncoated papers or fabrics.
1.2 This test method is not the only method for measurement of the oxygen transmission rate (OTR). There are other methods of
OTR determination that use other oxygen sensors and procedures.
1.3 The values stated in SI units are to be regarded as standard. Commonly used metric units used to report Oxygen Transmission
Rate are included in Terminology, Procedure, Precision and Bias sections and in the Calculation section of the Appendix.
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.
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:
D3985 Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor
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
F2622 Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
F2714 Test Method for Oxygen Headspace Analysis of Packages Using Fluorescent Decay
3. Terminology
3.1 Definitions:
3.1.1 Oxygen Transmission Rate (OTR)—(OTR), n—the quantity of oxygen gas passing through a unit area of the parallel surfaces
This test method is under the jurisdiction of ASTM Committee F02 on FlexiblePrimary Barrier Packaging and is the direct responsibility of Subcommittee F02.10 on
Permeation.
Current edition approved April 1, 2015Dec. 1, 2022. Published April 2015December 2022. Originally approved in 2015. Last previous edition approved in 2015 as
F3136 – 15. DOI: 10.1520/F3136-15.10.1520/F3136-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
F3136 − 22
of a plastic film per unit time under the conditions of test. The SI unit of transmission rate is the mol/(m —s). The test conditions
including temperature, relative humidity and oxygen partial pressure on both sides of the film must be stated in the report.
3.1.1.1 Discussion—
3 2 3
A commonly used unit of OTR is the cm (STP)/(m —day) at one atmosphere pressure difference where 1 cm (STP) is 44.62 μmol,
1 atmosphere is 0.1013 MPa, and one day is 86.4 × 10 s. The OTR in SI units is obtained by multiplying the value in commonly
-10
used units by 5.160 × 10 .
4. Summary of Test Method
4.1 The specimen is mounted as a sealed semi-barrier between two chambers, which together make up the permeation apparatus.
The sensing well which contains the oxygen sensor is slowly purged by a stream of pure nitrogen or other oxygen deficient gas
mixture until the oxygen concentration represents that of the purge gas. A commercial grade of compressed nitrogen containing
less than 0.05%0.05 % oxygen is recommended. A gas of known oxygen concentration, typically air or pure oxygen, is directed
into the opposite chamber, the driving well. Oxygen concentration in the sensing well containing the oxygen sensor is measured
periodically and the accumulating oxygen concentration recorded. The Oxygen Transmission Rate (OTR) parameter is determined
from the slope of the logarithm of accumulated oxygen concentration in the sensing well versus time as described in 14.2.
5. Significance and Use
5.1 The Oxygen Transmission Rate is an important determinant of packaging functionality afforded by packaging materials for
a wide variety of packaged products including food, pharmaceuticals and medical devices. In some applications, sufficient oxygen
must be allowed to permeate into the package. In others, the oxygen ingress must be minimized to maintain product quality.
5.2 Other ASTM Standard Methods to measure the oxygen transmission rate are described in Standard Test Method D3985 and
Standard Test Method F2622.
6. Interferences
6.1 Any leakage within the permeation apparatus or mounted packaging film will affect results. A means to assess leakage is
described in paragraph 9.2.
6.2 The condition of the sample film must be noted such as wrinkles or other defects can affect results.
7. Apparatus
7.1 Oxygen Gas Transmission Apparatus, as diagrammed in Fig. 1 with the following:
7.1.1 Permeation Apparatus (diffusion cell) shall consist of two metal halves, which, when closed upon the test specimen, will
define a known gas transmission area. The volume of the sensing well containing the oxygen sensor must be accurately known.
7.1.1.1 O-ring—A circular transmission area permits application of a static O-ring in a properly constructed O-ring groove in the
side of the permeation apparatus that does not contain the oxygen sensor. The test area of the sensing well is considered to be that
FIG. 1 A Practical Arrangement of Components for the Measurement of Oxygen Transmission Rate Using an Optical Florescent Oxygen
Sensor and a Permeation Apparatus
F3136 − 22
An acceptable example of a Permeation Apparatus (aka Diffusion Cell) is available from OxySense, Inc., 6000 S. Eastern Ave., Suite 14G, Las Vegas, NV 89119,
USA.pictured (above).
FIG. 2 Permeation Apparatus as described in this method (film specimen is shown adhered to the sensing well)
area established by the inside contact diameter of the compressed O-ring when the permeation apparatus is clamped shut. The area,
A, can be obtained by measuring the inside diameter of the imprint left by the O-ring on the specimen after it has been removed
from the permeation apparatus.
7.1.1.2 The sensing well of the permeation apparatus shall have a flat raised rim. Since this rim is a critical sealing surface against
which the test specimen is pressed, it shall be smooth and flat without radial scratches.
7.1.1.3 The sensing well of the permeation apparatus shall have a low-permeability window transparent to wavelengths used to
activate and read the oxygen sensor which is mounted within the sensing well.
7.1.1.4 The oxygen sensor incorporates a fluorophore that fluoresces in response to a certain wavelength of light, but is quenched
in the presence of oxygen. The oxygen quenching effect is calibrated to oxygen concentration. This sensing technology is identical
to the sensing technology described in ASTM Test Method F2714.
7.1.1.5 The permeability apparatus shall incorporated suitable fittings for the introduction and exhaust of gases without significant
loss or leakage.
7.2 It is necessary to control the temperature of the permeability apparatus during the test period. A simple heating/cooling
chamber regulated to 60.5°C,60.5 °C, is adequate for this purpose in which the apparatus is housed during the test period.
3 3
7.3 Flow meters having an operating range from 11 cm /min to 100 cm /min are required to monitor the flow rate of the nitrogen
purge stream and, if used, the oxygen or compressed air circulation stream. Sufficiently low flow rates and/or balanced pressures
on each side of the film are required to avoid stretching the specimen which would modify the effective sensing well volume.
7.4 An external light source provides sufficient light in the appropriate wavelength to activate the oxygen sensor.
7.5 A light detector, and associated electronics, determines the fluorescence decay constant, which is proportional to oxygen
concentration.
7.6 A computer is used to calculate the oxygen concentration at specified time intervals based on decay rates. The oxygen
transmission rate of the film is calculated from that data.
F3136 − 22
8. Reagents and Materials
8.1 Nitrogen enriched purge gas shall contain a known concentration of nitrogen. Commercial grade compressed nitrogen
(<0.05%(<0.05 % oxygen), certified pure nitrogen gas, cryogenically stored nitrogen or nitrogen enriched gas produced using
on-site generators may be used.
8.2 Transmission gas shall be of a known oxygen concentration with an oxygen concentration at least 10%10 % greater than the
purge gas. Typically, commercial grade compressed oxygen, certified gas or air is used. Also, regulated compressed air can be used
or the driving well can simply be left open to ambient air. When using ambient air as the test gas, it’s important to note the humidity
of the air as some materials are moisture sensitive and their measured oxygen transmission rates can change with varying humidity
levels. Classic examples of these material include (but not limited to): Coated Papers, polyimide and Ethylene Vinyl Alcohol
copolymers (EVOH).
8.3 Sealing Grease—High-viscosity silicone stop cock grease or high-vacuum grease is required for sealing the specimen film in
the diffusion cell.
9. Precautions
9.1 Temperature is a critical parameter affecting the measurement of OTR. Careful temperature control can help to minimize
variations due to temperature fluctuations. During testing, the temperature shall be monitored and controlled to 6 0.5°C.0.5 °C.
Temperature variations should be minimized. The average temperature and a range of temperatures during a test shall both be
recorded.
9.2 Oxygen that leaks into the sensing well through faulty valves, fittings, or through an improperly sealed window can
significantly affect the accuracy of the measurement. Periodic leak checks using impervious films such as metal foils with
thicknesses ≥25 μm (with their expected permeations of zero) should be taken to identify suspected system leaks. Leak check
permeation tests should be run at least every 3-6 months and each test should be run for a minimum of 12 hours.
10. Sampling
10.1 Film samples used for the determination of OTR shall be representative of materials for which the data are required. Care
shall be taken to ensure that samples are representative of conditions across the width and along the length of a roll of film.
11. Test Specimens
11.1 Test specimens shall be representative of the material and shall be free of defects including wrinkles, creases, and pinholes,
unless these are characteristics of the material being tested and included in the material description.
11.2 Average thickness shall be determined 6 3 μm using a calibrated dial gage (or equivalent) at a minimum of five points
distributed over the entire test area. Maximum, minimum, and average values shall be recorded. Sample thickness need not be
measured for determination of sample OTR only.
11.3 If the test specimen is of an asymmetrical construction, the two surface shall be marked by appropriate distinguishing marks
and the orientation of the test specimen within the permeation apparatus shall be reported.
12. Calibration
12.1 General Approach—The oxygen sensor fluoresces when exposed to certain wavelengths of light. Oxygen quenches the
fluorescent decay response. The sensor apparatus utilizes a light source to deliver light to the oxygen sensor which, in turn,
fluoresces. This light is measured by the detector. The detector determines the exponential fluorescent response decay constant,
which is calibrated to oxygen concentration.
12.2 Calibration—The sensor system is calibrated by measuring oxygen concentration at two known values, typically air
(20.9%(20.9 % oxygen) and pure nitrogen (0%(0 % oxygen). These values define a calibration curve from which unknown oxygen
levels may be determined. Alternatively, 2 gases of known concentrations nearer to the level under test may prove to yield a better
calibration value (perhaps 3%3 % and 0%0 % oxygen).
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13. Procedure
13.1 Apply a thin layer of sealing grease (see 8.3) around the raised rim of the sensing well opposite the O-ring. Place the
specimen on the greased surface, taking care to avoid wrinkles or creases. Close and secure the permeation apparatus.
13.2 The system can be calibrated with the test specimen in place.
13.2.1 Open both the inlet and outlet valves connected to the sensing well of the permeation apparatus. If using air as the upper
oxygen level calibration gas, there is no need to purge the sensing well as it already contains air and readings from the sensor can
be taken immediately. If using other than air as the upper oxygen level calibration gas, then the sensing well must be purged with
that gas. Purge the sensing well with the higher oxygen level calibration gas at 5-10 cm /min. Note that whenever purging with
a sample in the chamber, care must be taken to avoid stretching or bulging the film. A flow rate of 5-10 cm /min with valves open
has been determined to not cause undue sample bulging or stretching. Oxygen concentration should be monitored until the reported
value does not change. Expect to purge with at least 5 chamber volumes of gas (typically 5-10 minutes). Once the indicated
concentration remains steady, calibrate the oxygen sensor to this known value.
13.2.2 Purge the sensing well with the lower oxygen level calibration gas (typically nitrogen) at a flow rate o
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