ASTM D7132-19

• Abstract:

  ABSTRACT; This test method covers the determination of retained blowing agent in extruded polystyrene foam. The internal standard preparation procedures of the material are presented in details. The procedures for determination of retained blowing agent in extruded polyester foam are presented in details.; SCOPE; 1.1 This test method covers the determination of retained blowing agent in extruded polystyrene foam. ; 1.2 This test method applies to organic blowing agents which lend themselves to a convenient analysis by gas chromatography. The method is not applicable to blowing agents such as nitrogen, carbon dioxide, or water. ; 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 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. ; Note 1: There is no known ISO equivalent to this standard. ; 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.

• Status: Published
• Publication Date: 31-Mar-2019
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

• Replaces: ASTM D7132-14 - Standard Test Method for Determination of Retained Blowing Agent in Extruded Polystyrene Foam
• Effective Date: 01-Apr-2019

Overview

ASTM D7132-19: Standard Test Method for Determination of Retained Blowing Agent in Extruded Polystyrene Foam is an internationally recognized test method developed by ASTM International. This standard specifies procedures for quantitatively determining the retained organic blowing agent in extruded polystyrene foam using gas chromatography. Accurate measurement of retained blowing agents is essential for assessing product performance, environmental impact, and compliance with regulatory requirements in the plastics and insulation industries.

Key Topics

• Applicability: The standard applies to extruded polystyrene foam materials containing organic blowing agents that can be analyzed by gas chromatography. It is not suitable for inorganic agents such as nitrogen, carbon dioxide, or water.
• Test Method: The retained blowing agent is released by dissolving the foam in a solvent (e.g., toluene), followed by gas chromatographic analysis using an internal standard for quantification.
• Precision and Quality Assurance: The method includes calibration with reference solutions, daily quality assurance parameters, and requirements for instrument performance and sample handling to ensure reliable results.
• Safety and Sample Handling: Instructions emphasize proper safety, health, and environmental practices. Careful sample preparation is necessary to minimize loss of volatile blowing agents and ensure representative analysis.
• Results Interpretation: Results are typically expressed as weight percent of retained blowing agent in the foam sample, determined through calibration and quality control measures.

Applications

The ASTM D7132-19 standard test method has wide-ranging applications in industries and laboratory settings that utilize or manufacture extruded polystyrene foam:

• Product Quality Control: Manufacturers of extruded polystyrene boards use this method to monitor retained blowing agent levels, which influence insulation performance and material properties.
• Environmental Compliance: Tracking the amount of retained organic blowing agents helps ensure products meet environmental regulations on volatile organic compound (VOC) emissions and ozone depletion potential.
• Research and Development: Laboratories leverage this standard for developing new foam formulations, optimizing blowing agent usage, and evaluating changes in manufacturing processes.
• Regulatory Documentation: Provides a consistent and internationally recognized approach for regulatory submissions and documentation in the construction, packaging, and insulation sectors.
• Performance Verification: Enables suppliers and customers to verify foam composition, ensuring reliability and traceability of materials for end-use applications.

Related Standards

For organizations and laboratories seeking to implement or complement ASTM D7132-19, the following related standards may provide additional test methods or guidance:

• ASTM D3576 - Standard Test Method for Cell Size of Rigid Cellular Plastics
• ASTM D1622 - Standard Test Method for Apparent Density of Rigid Cellular Plastics
• ASTM C518 - Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus

Note: There is no direct ISO equivalent to ASTM D7132-19 at the time of writing.

Practical Value

The use of ASTM D7132-19 ensures reliable, repeatable, and accurate determination of retained blowing agents in extruded polystyrene foam. This supports manufacturers in producing high-quality insulation materials, enables compliance with evolving environmental standards, and provides robust technical data for product development and market access. By following this standardized gas chromatographic methodology, stakeholders can achieve greater transparency and efficiency in product evaluation and regulatory reporting.

Keywords: ASTM D7132, retained blowing agent, extruded polystyrene foam, gas chromatography, plastic insulation, quality control, VOC analysis, foam manufacturing standard.

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: D7132 − 19
Standard Test Method for
Determination of Retained Blowing Agent in Extruded
Polystyrene Foam
This standard is issued under the fixed designation D7132; 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* matograph (GC) with standard solutions allows conversion of
the GC response to the amount of blowing agent retained in the
1.1 This test method covers the determination of retained
foam matrix.
blowing agent in extruded polystyrene foam.
1.2 This test method applies to organic blowing agents
3. Interferences
which lend themselves to a convenient analysis by gas chro-
3.1 The gas chromatogram has the potential to contain a
matography. The method is not applicable to blowing agents
signal(s) from the polymer matrix that interferes with the
such as nitrogen, carbon dioxide, or water.
signal(s) from the blowing agent components. Test calibration
1.3 The values stated in SI units are to be regarded as
solutions with and without the polymer matrix to rule out any
standard. No other units of measurement are included in this
interference.These calibration solutions shall contain about the
standard.
same amount of dissolved resin as in the foam sample being
1.4 This standard does not purport to address all of the
analyzed.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Apparatus
priate safety, health, and environmental practices and deter-
4.1 Any GC equipped with a column suitable for resolving
mine the applicability of regulatory limitations prior to use.
blowing agent components is suitable for use. For example, if
NOTE 1—There is no known ISO equivalent to this standard. separating non-polar blowing agents, a 100 % dimethyl-
polysiloxane with 530-µm thick film and 30-m length is a
1.5 This international standard was developed in accor-
reasonable selection. If separating polar blowing agents, a 50
dance with internationally recognized principles on standard-
% dipheny/50 % dimethyl polysiloxane column with 530-µm
ization established in the Decision on Principles for the
thick film and 30-m length is suitable. Typical operating
Development of International Standards, Guides and Recom-
parameters for the GC are:
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. Head pressure (kPa) 50
Initial oven temperature (°C) 50
Initial hold time (min) 3.5
2. Summary of Test Method
Temperature program rate (°C/min) 25
Final temperature (°C) 150
2.1 Polystyrene foams are made with a variety of blowing
Final hold time (min) 3
agents such as hydrocarbons, hydrofluorocarbons, ethers,
Injector temperature (°C) 250
Detector temperature (°C) 300
ketones, and other volatile organic chemicals.Afraction of the
Carrier gas He
blowing agent used in the manufacture of foam is retained in 3
Carrier gas flow rate (cm /min) 30
theproduct,someresidinginthecellwallsandsomeentrapped
Injection sample size (µL) 0.2
inside the cells. This test method is based on releasing the
NOTE 2—An autosampler is not recommended as the transfer of a
retained blowing agent by dissolving the polystyrene foam in a
solution containing volatile components can lead to loss of the volatile
solvent, such as toluene, and then analyzing the solution for its
analyte.
components by gas chromatography. An internal standard is
4.2 Analytical balance with at least 250 g full scale and 0.1
used as a reference analyte and calibration of the gas chro-
mg resolution.
4.3 Instrument grade air supplied at 515 6 40 kPa, helium
at 450 6 40 kPa, and hydrogen at 380 6 40 kPa.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods. 4.4 Volumetric flasks.
Current edition approved April 1, 2019. Published May 2019. Originally
3 3
4.5 1-cm syringe with Chaney Adapter, and 10-cm gas
approved in 2005. Last previous edition approved in 2014 as D7132 – 14. DOI:
10.1520/D7132-19. tight syringe with Chaney Adapter.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7132 − 19
4.6 1-µL syringe. 8.1.2 Fill the 10-cm syringe from the flask using the
3 Chaney adapter for volume control.
4.7 Tall, wide mouth 125-cm sample bottles with caps and
8.1.3 Inject the toluene into a pre-weighed sample bottle.
teflon/silicon septa.
Weigh the bottle. The weight shall be ⁄10 of the weight
4.8 30-cm serum vials with crimp on teflon/silicon septa.
obtained in step 8.1.1 within 0.01 gram.
4.9 Rubber sleeve stoppers for volumetric flask. 3
8.2 Add about 90 cm of toluene to another volumetric flask
4.10 Septa for GC. that meets the needs for the number of standards and samples
for the analysis. Cap the flask with an unused rubber sleeve
4.11 Ice water bath.
stopper. Remove any static and dry the outside of flask with an
4.12 Weights to keep sample bottle submerged.
ionized air blower.
4.13 Refrigerator for sample storage.
8.3 Place the flask on the balance pan, allow it to stabilize,
and tare the balance.
4.14 Insulated mailing containers with ice packs for ship-
ping samples.
8.4 The flask shall not cause the balance to respond before
actually touching the balance pan.
5. Reagents and Materials
8.5 Inject 0.2 to 0.4 cm heptane into the flask and weigh to
5.1 Certified grade toluene with minimum purity of 99.8
the nearest 0.1 mg (W ).
istd
mol%.
8.6 Dilute to the mark with toluene. It is acceptable to retain
5.2 Certified grade normal heptane with minimum purity of
this internal standard (ISTD) solution for 24 hours.
99.8 mol%.
5.3 Instrument grade standards for blowing agents to be
9. Calibration
analyzed.
9.1 Tareanempty30-cm serumvial(withaseptaandseal).
6. Hazards 9.2 Fill the serum vial with toluene to about 90 % capacity.
Affix the septa and seal. Obtain the weight of the toluene to 0.1
6.1 Some blowing agents are compressed liquids or gases at
mg (W ).
room temperature. Appropriate care shall be taken when
preparing calibration solutions from such blowing agents.
9.3 Tare the balance with the vial containing the toluene.
Inject an appropriate mass of blowing agent into the vial.
7. Sampling, Test Specimens, and Test Units
Weigh the vial and record the weight to the nearest 0.1 mg
(W ). Repeat with additional blowing agents to create a
7.1 Record the manufacture date of the foam and the date of 2
combined calibration solution. This solution is not to be
material sampling.
retained for more than eight hours.
7.2 Tare sample bottle with cap and septum. Cut a piece of
NOTE 6—The amount of blowing agent added to create a calibration
foam using a sharp knife, transfer it immediately to the sample
solution should bracket the expected concentration of the target blowing
bottle, and seal with cap and septum. Record the sample
agent in the sample.
NOTE 7—See Annex A1 for injecting volatile or gaseous blowing
weight.
agents.
NOTE 3—The cutting action produces open cells and the blowing agent
9.4 Using the calibrated syringe and the technique shown in
trapped in these cells is lost immediately. The sample size and shape shall
Fig. 1, withdraw 10.0 cm of the ISTD solution and inject into
be such as to minimize the ratio of area of cut surfaces to total surface
area. The foam sample shall also be of dimensions such that it can easily
a tightly capped empty sample bottle.
be placed in the sample bottle without causing any break or tear in the
9.5 Place the sample bottle containing the ISTD on the
sample. To establish the optimum sample size, ma
...

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: D7132 − 14 D7132 − 19
Standard Test Method for
Determination of Retained Blowing Agent in Extruded
Polystyrene Foam
This standard is issued under the fixed designation D7132; 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 the determination of retained blowing agent in extruded polystyrene foam.
1.2 This test method applies to organic blowing agents which lend themselves to a convenient analysis by gas chromatography.
The method is not applicable to blowing agents such as nitrogen, carbon dioxide, or water.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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 to determine the
applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
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. Summary of Test Method
2.1 Polystyrene foams are made with a variety of blowing agents such as hydrocarbons, hydrofluorocarbons, ethers, ketones,
and other volatile organic chemicals. A fraction of the blowing agent used in the manufacture of foam is retained in the product,
some residing in the cell walls and some entrapped inside the cells. This test method is based on releasing the retained blowing
agent by dissolving the polystyrene foam in a solvent, such as toluene, and then analyzing the solution for its components by gas
chromatography. An internal standard is used as a reference analyte and calibration of the gas chromatograph (GC) with standard
solutions allows conversion of the GC response to the amount of blowing agent retained in the foam matrix.
3. Interferences
3.1 The gas chromatogram has the potential to contain a signal(s) from the polymer matrix that interferes with the signal(s) from
the blowing agent components. Test calibration solutions with and without the polymer matrix to rule out any interference. These
calibration solutions shall contain about the same amount of dissolved resin as in the foam sample being analyzed.
4. Apparatus
4.1 Any GC equipped with a column suitable for resolving blowing agent components is suitable for use. For example, if
separating non-polar blowing agents, a 100 % dimethyl-polysiloxane with 530-μm thick film and 30-m length is a reasonable
selection. If separating polar blowing agents, a 50 % dipheny/50 % dimethyl polysiloxane column with 530-μm thick film and
30-m length is suitable. Typical operating parameters for the GC are:
Head pressure (kPa) 50
Initial oven temperature (°C) 50
Initial hold time (min) 3.5
Temperature program rate (°C/min) 25
Final temperature (°C) 150
Final hold time (min) 3
Injector temperature (°C) 250
Detector temperature (°C) 300
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved March 1, 2014April 1, 2019. Published March 2014May 2019. Originally approved in 2005. Last previous edition approved in 20132014 as
D7132 – 13.14. DOI: 10.1520/D7132-14.10.1520/D7132-19.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7132 − 19
Carrier gas He
Carrier gas flow rate (cm /min) 30
Injection sample size (μL) 0.2
NOTE 2—An autosampler is not recommended as the transfer of a solution containing volatile components can lead to loss of the volatile analyte.
4.2 Analytical balance with at least 150250 g full scale and 0.1 mg resolution.
4.3 Instrument grade air supplied at 515 6 40 kPa, helium at 450 6 40 kPa, and hydrogen at 380 6 40 kPa.
4.4 100-cmVolumetric volumetric flasks.
3 3
4.5 1-cm syringe with Chaney Adapter, and 10-cm gas tight syringe with Chaney Adapter.
4.6 1-μL syringe.
4.7 Tall, wide mouth 125-cm sample bottles with caps and teflon/silicon septa.
4.8 30-cm serum vials with crimp on teflon/silicon septa.
4.9 Rubber sleeve stoppers for volumetric flask.
4.10 Septa for GC.
4.11 Ice water bath.
4.12 Weights to keep sample bottle submerged.
4.13 Refrigerator for sample storage.
4.14 Insulated mailing containers with ice packs for shipping samples.
5. Reagents and Materials
5.1 Certified grade toluene with minimum purity of 99.8 mol%.
5.2 Certified grade normal heptane with minimum purity of 99.8 mol%.
5.3 Instrument grade standards for blowing agents to be analyzed.
6. Hazards
6.1 Some blowing agents are compressed liquids or gases at room temperature. Appropriate care shall be taken when preparing
calibration solutions from such blowing agents.
7. Sampling, Test Specimens, and Test Units
7.1 Record the manufacture date of the foam and the date of material sampling.
7.2 Tare sample bottle with cap and septum. Cut a piece of foam using a sharp knife, transfer it immediately to the sample bottle,
and seal with cap and septum. Record the sample weight.
NOTE 3—The cutting action produces open cells and the blowing agent trapped in these cells is lost immediately. The sample size and shape shall be
such as to minimize the ratio of area of cut surfaces to total surface area. The foam sample shall also be of dimensions such that it can easily be placed
in the sample bottle without causing any break or tear in the sample. To establish the optimum sample size, make some preliminary measurements as
a function of sample size/shape until a constant value of the retained blowing agent is obtained.
NOTE 4—If testing foam board, the sample dimensions and location such as surface or core should be reported.
7.3 Typically, the sample weight is 1 gram.
7.4 Store the samples at about 4°C, and analyze within a week.
NOTE 5—When samples need to be shipped, use an insulated container equipped with frozen ice packs. Shipping should be by overnight service.
7.5 Record the date of the blowing agent analysis.
8. Internal Standard Preparation
8.1 Affix a Chaney adapter to the 10-cm syringe and calibrate the syringe in accordance with steps 8.1.1 – 8.1.3.
3 3
8.1.1 Measure and record the weight of 100 cm of toluene in a 100-cm volumetric flask.
8.1.2 Fill the 10-cm syringe from the flask using the Chaney adapter for volume control.
8.1.3 Inject the toluene into a pre-weighed sample bottle. Weigh the bottle. The weight shall be ⁄10 of the weight obtained in
step 8.1.1 within 0.01 gram.
3 3
8.2 Add about 90 cm of toluene to another 100-cm volumetric flask. flask that meets the needs for the number of standards
and samples for the analysis. Cap the flask with an unused rubber sleeve stopper. Remove any static and dry the outside of flask
with an ionized air blower.
8.3 Place the flask on the balance pan, allow it to stabilize, and tare the balance.
D7132 − 19
NOTE 6—The flask shall not cause the balance to respond before actually touching the balance pan.
8.4 The flask shall not cause the balance to respond before actually touching the balance pan.
8.5 Inject 0.2 to 0.4 cm heptane into the flask and weigh to the nearest 0.1 mg (W ).
istd
8.6 Dilute to the mark with toluene. It is acceptable to retain this internal standard (ISTD) solution for 24 hours.
9. Calibration
9.1 Tare an empty 30-cm serum vial (with a septa and seal).
9.2 Fill the serum vial with toluene to about 90 % capacity. Affix the septa and seal. Obtain the weight of the toluene to 0.1 mg
(W ).
9.3 Tare the balance with the vial containing the toluene. Inject 1 to 2 g an appropriate mass of blowing agent into the vial.
Weigh the vial and record the weight to the nearest 0.1 mg (W ). Repeat with additional blowing agents to create a combined
calibration solution. This solution is not to be retained for more than eight hours.
NOTE 7—See Annex A1 for injecting vol
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