ASTM D1975-21

Standard Test Method for Environmental Stress Crack Resistance of Plastic Injection Molded Open Head Pails

SIGNIFICANCE AND USE
5.1 These procedures provide an indication of the environmental stress-crack resistance of injection molded open head pails, covers, and components from a selected group or lot. Provided the thermal history of each container is constant, this test method may be used for determining the applicability of various plastic resins and mold designs for injection molding of open head pails and covers.  
5.2 The environmental stress-crack that occurs is indicative of what results when a container is exposed to agents such as soaps, organics, or any surface active solutions while under environmental conditions of stress.  
5.3 Environmental stress-cracking is a mechanism of chemical attack that is highly dependent upon the test reagent, resin, container manufacturing or processing history, exposure temperature, applied stress, and other factors. The combination of these factors may result in eventual stress-crack failure.  
5.4 Procedure A minimizes the potential for test variability by providing the user with rigidly defined test conditions. This test method may be used for production quality control of injection molded open head containers.  
5.5 Procedure B allows the user to select and evaluate extreme individual elements or the interaction of several test levels on container performance. These conditions are established based on laboratory experience and available knowledge of the distribution environment. This test method may be used for identifying critical stresses which could aid in container design or help in minimizing the occurrence of these stresses during distribution.  
5.6 This test method is intended only as a pass/fail procedure in accordance with the user's specification, or as agreed upon between the user and the supplier. It is not intended as a predictor or indicator of field performance regarding time to failure.
SCOPE
1.1 This test method provides procedures for an indication of the environmental stress crack resistance of plastic injection molded open head pails, covers, and components as a summation of the effects of container design, resin, manufacturing conditions, field performance, and other factors.  
1.2 This test method may be used to evaluate a container's resistance to mechanical failure by cracking when in the presence of chemical and physical stresses.  
1.3 Two procedures are provided as follows:  
1.3.1 Procedure A, Specified Stress-Crack Resistance Test Method—This procedure is particularly useful for quality control since the conditions of the test are specified.  
1.3.2 Procedure B, User Selected Stress-Crack Resistance Test Method—This procedure allows individual selection of test levels and is particularly useful as a design and development tool.  
1.4 These procedures are not designed to test the ability of the cover gasketing material or closure to retain the test reagent. Loss or leakage of the reagent through these openings does not constitute container failure. However, this may indicate an internal pressure loss that might affect test results.  
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.6 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. Specific warning statements are given in 6.2, 10.2.3, 10.2.4, 10.2.6, and 10.2.8.  
1.7 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 Trad...

General Information

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 83.140.99 - Other rubber and plastics products
• Technical Committee: D10 - Packaging
• Drafting Committee: D10.21 - Shipping Containers and Systems - Application of Performance Test Methods

Relations

• Refers: ASTM D4332-13 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 15-Mar-2013
• Refers: ASTM E122-09e1 - Standard Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
• Effective Date: 01-Aug-2011
• Refers: ASTM D996-10a - Standard Terminology of Packaging and Distribution Environments
• Effective Date: 01-Dec-2010
• Refers: ASTM E122-09 - Standard Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
• Effective Date: 01-Aug-2009
• Refers: ASTM E122-07 - Standard Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
• Effective Date: 01-Oct-2007
• Refers: ASTM D4332-01(2006) - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 01-Nov-2006
• Refers: ASTM D996-04 - Standard Terminology of Packaging and Distribution Environments
• Effective Date: 01-Apr-2004
• Refers: ASTM D996-02 - Standard Terminology of Packaging and Distribution Environments
• Effective Date: 10-Apr-2002
• Refers: ASTM D996-99 - Standard Terminology of Packaging and Distribution Environments
• Effective Date: 10-Apr-2002
• Refers: ASTM D4332-01 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 10-Apr-2001
• Refers: ASTM D4332-99 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 10-Apr-2001
• Refers: ASTM D4332-01e2 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 10-Apr-2001
• Refers: ASTM D4332-00 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 10-Apr-2001
• Refers: ASTM D4332-01e1 - Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
• Effective Date: 10-Apr-2001
• Refers: ASTM E122-99 - Standard Practice for Calculating Sample Size to Estimate, With a Specified Tolerable Error, the Average for Characteristic of a Lot or Process
• Effective Date: 10-Oct-2000

Overview

ASTM D1975-21 is the Standard Test Method for Environmental Stress Crack Resistance of Plastic Injection Molded Open Head Pails. Developed by ASTM International, this method provides procedures for evaluating the resistance of injection molded plastic open head pails, covers, and related components to stress cracking under defined chemical and physical conditions. This standard is widely utilized in the packaging industry to ensure the durability and integrity of plastic containers, especially when exposed to harsh environments or chemical agents.

Environmental stress cracking is a common failure mode for plastic containers, particularly when they are subjected to material stresses and chemical exposures during use, transport, or storage. ASTM D1975-21 outlines both quality control and design-focused testing approaches, supporting the selection of suitable resins, mold designs, and manufacturing practices.

Key Topics

• Environmental Stress Crack Resistance (ESCR): The standard defines procedures to measure the susceptibility of plastic pails to cracking when exposed to stress and potentially aggressive chemical agents.
• Injection Molded Plastic Pails: Focuses specifically on open head pails and covers made via injection molding, a method common in industrial and commercial packaging.
• Two Test Procedures:
  • Procedure A: Specified Stress-Crack Resistance Test
    Delivers consistent, repeatable test conditions for quality control.
  • Procedure B: User Selected Stress-Crack Resistance Test
    Offers flexibility for customized testing, valuable in product design and development.
• Test Variables: Considers factors such as plastic resin type, container manufacturing history, reagent type, exposure temperature, and applied load stress.
• Pass/Fail Criteria: Designed as a pass/fail assessment tool, in line with user specifications or supplier agreements, rather than as a predictor of field life.

Applications

ASTM D1975-21 is highly relevant in industries where plastic open head pails are used to store or transport soaps, organic materials, or other chemicals. Common applications include:

• Quality Control: Routine production batch verification to ensure compliance with stress-crack resistance requirements.
• Material Selection: Comparing the performance of various resins and molded designs for optimal environmental stress crack resistance.
• Design & Development: Evaluating prototype containers to identify potential weaknesses and improve durability before market release.
• Distribution Environment Validation: Simulating shipping and handling conditions to minimize the risk of container failure during logistics.
• Regulatory and Compliance Testing: Supporting documentation for performance claims and regulatory submissions concerning container durability.

The test methods help manufacturers prevent costly failures and product recalls, improve package reliability, and demonstrate compliance with industry standards.

Related Standards

The following standards are referenced in ASTM D1975-21 and provide complementary guidance:

• ASTM D996: Terminology of Packaging and Distribution Environments - Provides definitions relevant to packaging and distribution.
• ASTM D4332: Practice for Conditioning Containers, Packages, or Packaging Components for Testing - Details procedures for conditioning packaging items prior to testing.
• ASTM E122: Practice for Calculating Sample Size to Estimate, with Specified Precision, the Average for a Characteristic of a Lot or Process - Supports statistical sampling and analysis.

Keywords: environmental stress cracking, plastic pails, injection molded containers, stress crack resistance, ASTM D1975, packaging testing, quality control, plastic container durability, chemical resistance, container design testing.

By applying ASTM D1975-21, organizations can enhance the safety, reliability, and market acceptance of plastic open head containers across diverse industries.

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: D1975 − 21
Standard Test Method for
Environmental Stress Crack Resistance of Plastic Injection
Molded Open Head Pails
This standard is issued under the fixed designation D1975; 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* ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method provides procedures for an indication
mendations issued by the World Trade Organization Technical
of the environmental stress crack resistance of plastic injection
Barriers to Trade (TBT) Committee.
molded open head pails, covers, and components as a summa-
tion of the effects of container design, resin, manufacturing
2. Referenced Documents
conditions, field performance, and other factors.
2.1 ASTM Standards:
1.2 This test method may be used to evaluate a container’s
D996 Terminology of Packaging and Distribution Environ-
resistance to mechanical failure by cracking when in the
ments
presence of chemical and physical stresses.
D4332 Practice for Conditioning Containers, Packages, or
Packaging Components for Testing
1.3 Two procedures are provided as follows:
E122 Practice for Calculating Sample Size to Estimate,With
1.3.1 Procedure A, Specified Stress-Crack Resistance Test
Specified Precision, the Average for a Characteristic of a
Method—This procedure is particularly useful for quality
Lot or Process
control since the conditions of the test are specified.
1.3.2 Procedure B, User Selected Stress-Crack Resistance
3. Terminology
Test Method—This procedure allows individual selection of
3.1 Definitions—Reference Terminology D996 for defini-
test levels and is particularly useful as a design and develop-
tions applicable to this test method.
ment tool.
3.2 Definitions of Terms Specific to This Standard:
1.4 These procedures are not designed to test the ability of
3.2.1 environmental stress crack—an external or internal
the cover gasketing material or closure to retain the test
crack that develops when a container is exposed to chemical or
reagent. Loss or leakage of the reagent through these openings
physical stresses, or both.
does not constitute container failure. However, this may
indicate an internal pressure loss that might affect test results.
3.2.2 stress crack failure—any environmental stress crack
that causes a loss or leakage of the test reagent shall be
1.5 The values stated in inch-pound units are to be regarded
interpreted as container failure.
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
4. Summary of Test Method
and are not considered standard.
4.1 The environmental stress-crack resistance is determined
1.6 This standard does not purport to address all of the
by subjecting an injection molded open head pail and cover
safety concerns, if any, associated with its use. It is the
that is filled and sealed with a stress-crack reagent to a
responsibility of the user of this standard to establish appro-
mechanical top load at elevated temperatures. The recom-
priate safety, health, and environmental practices and deter-
mendedminimumtestdurationshallbe14days,orasspecified
mine the applicability of regulatory limitations prior to use.
by the user. The time to stress-crack failure is observed.
Specific warning statements are given in 6.2, 10.2.3, 10.2.4,
4.1.1 ProcedureAexposesaminimumofthreecontainersto
10.2.6, and 10.2.8.
specified levels of chemical and physical stresses.
1.7 This international standard was developed in accor-
4.1.2 Procedure B exposes containers to varying chemical
dance with internationally recognized principles on standard-
and physical stresses based on the user’s knowledge and
objectives.
This test method is under the jurisdiction of ASTM Committee D10 on
Packaging and is the direct responsibility of Subcommittee D10.21 on Shipping
Containers and Systems - Application of Performance Test Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2021. Published November 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1991. Last previous edition approved in 2016 as D1975 – 16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D1975-21. the ASTM website.
*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
D1975 − 21
5. Significance and Use 7. Reagents
5.1 These procedures provide an indication of the environ- 7.1 ProcedureA; Nonyl Phenoxypoly (Ethyleneoxy) Ethanol
mental stress-crack resistance of injection molded open head Solution—Prepare a 10 % solution, by volume, of the stress-
pails, covers, and components from a selected group or lot. cracking agent and water.
Provided the thermal history of each container is constant, this
NOTE 1—Due to the viscosity of the stress-cracking agent, it is helpful
test method may be used for determining the applicability of
to prepare the solution at an elevated temperature. A maximum tempera-
variousplasticresinsandmolddesignsforinjectionmoldingof
ture of 122 °F (50° C) is an acceptable level provided caution is used to
avoid prolonged heating and eventual volume losses.
open head pails and covers.
7.2 Procedure B—Any reagent or proprietary product
5.2 The environmental stress-crack that occurs is indicative
(liquid, solid, etc.) that is potentially a stress-cracking agent.
of what results when a container is exposed to agents such as
soaps, organics, or any surface active solutions while under
8. Sampling
environmental conditions of stress.
8.1 Aminimum of three containers are required for this test
5.3 Environmental stress-cracking is a mechanism of
method. When possible, for direct comparison, the test con-
chemical attack that is highly dependent upon the test reagent,
tainers should be produced on the same equipment, including
resin, container manufacturing or processing history, exposure
mold and under identical conditions from the same production
temperature, applied stress, and other factors.The combination
lot. It is suggested that test container resin, machine, mold, and
of these factors may result in eventual stress-crack failure.
molding conditions be thoroughly documented to improve
5.4 Procedure A minimizes the potential for test variability
statistical reliability of the test data. (Practice E122.)
by providing the user with rigidly defined test conditions. This
9. Conditioning
test method may be used for production quality control of
injection molded open head containers.
9.1 Condition empty test containers at 73 °F 6 2 °F (23 °C
6 1.3 °C) 50 % 6 3 % relative humidity for 48 h prior to
5.5 Procedure B allows the user to select and evaluate
testing (see Practice D4332).
extreme individual elements or the interaction of several test
levels on container performance. These conditions are estab-
10. Procedure
lishedbasedonlaboratoryexperienceandavailableknowledge
10.1 Procedure A—Specified Stress-Crack Resistance
of the distribution environment. This test method may be used
Method:
for identifying critical stresses which could aid in container
10.1.1 Place the environmental chamber set point control at
design or help in minimizing the occurrence of these stresses
122 °F 6 2 °F (50 °C 6 1.3 °C) and allow it to reach
during distribution.
equilibrium. Fill each test specimen to 98 % of the container’s
5.6 This test method is intended only as a pass/fail proce-
maximum volumetric capacity (with cover in place) with the
dure in accordance with the user’s specification, or as agreed
test reagent. Apply the cover to the pail as specified by the
upon between the user and the supplier. It is not intended as a
manufacture’s closing instructions.
predictor or indicator of field performance regarding time to
10.1.2 Place test specimens in the environmental chamber
failure.
on an even horizontal surface. Place an identical pail filled to
rated capacity with sand or water on top of each test specimen.
6. Apparatus
Apply additional weight (if needed) to the top of the pail filled
6.1 Environmental Chamber—The environmental chamber
with sand or water to bring the total top load weight (sand or
should be capable of maintaining a temperature control of
water pail plus weight) up to the values specified in Table 1.
62.5 °F (61.4 °C) of set point. For best circulation and a
Example is shown in Fig. X1.1 in Appendix X1. Record the
constant temperature throughout, a forced air system is recom-
time and date the test was started.
mended.
10.1.3 Inspect the test pails and covers daily for any
6.2 Top Load—Requires a pail identical to the test pail be
evidence of stress-crack failure. Inspection of the cover may
filled to rated capacity or weight and
...

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: D1975 − 16 D1975 − 21
Standard Test Method for
Environmental Stress Crack Resistance of Plastic Injection
Molded Open Head Pails
This standard is issued under the fixed designation D1975; 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 Scope*
1.1 This test method provides procedures for an indication of the environmental stress crack resistance of plastic injection molded
open head pails, covers, and components as a summation of the effects of container design, resin, manufacturing conditions, field
performance, and other factors.
1.2 This test method may be used to evaluate a container’s resistance to mechanical failure by cracking when in the presence of
chemical and physical stresses.
1.3 Two procedures are provided as follows:
1.3.1 Procedure A, Specified Stress-Crack Resistance Test Method—This procedure is particularly useful for quality control since
the conditions of the test are specified.
1.3.2 Procedure B, User Selected Stress-Crack Resistance Test Method—This procedure allows individual selection of test levels
and is particularly useful as a design and development tool.
1.4 These procedures are not designed to test the ability of the cover gasketing material or closure to retain the test reagent. Loss
or leakage of the reagent through these openings does not constitute container failure. However, this may indicate an internal
pressure loss that might affect test results.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety problems,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 warning statements are given in 6.2, 10.2.3, 10.2.4,
10.2.6, and 10.2.8.
1.7 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.
This test method is under the jurisdiction of ASTM Committee D10 on Packaging and is the direct responsibility of Subcommittee D10.21 on Shipping Containers and
Systems - Application of Performance Test Methods.
Current edition approved June 1, 2016Nov. 1, 2021. Published July 2016November 2022. Originally approved in 1991. Last previous edition approved in 20102016 as
D1975 – 95 (2010).D1975 – 16. DOI: 10.1520/D1975-16.10.1520/D1975-21.
*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
D1975 − 21
2. Referenced Documents
2.1 ASTM Standards:
D996 Terminology of Packaging and Distribution Environments
D4332 Practice for Conditioning Containers, Packages, or Packaging Components for Testing
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or
Process
3. Terminology
3.1 Definitions—Reference Terminology D996 for definitions applicable to this test method.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 environmental stress crack—an external or internal crack that develops when a container is exposed to chemical or physical
stresses, or both.
3.2.2 stress crack failure—any environmental stress crack that causes a loss or leakage of the test reagent shall be interpreted as
container failure.
4. Summary of Test Method
4.1 The environmental stress-crack resistance is determined by subjecting an injection molded open head pail and cover that is
filled and sealed with a stress-crack reagent to a mechanical top load at elevated temperatures. The recommended minimum test
duration shall be 14 days, or as specified by the user. The time to stress-crack failure is observed.
4.1.1 Procedure A exposes a minimum of three containers to specified levels of chemical and physical stresses.
4.1.2 Procedure B exposes containers to varying chemical and physical stresses based on the user’s knowledge and objectives.
5. Significance and Use
5.1 These procedures provide an indication of the environmental stress-crack resistance of injection molded open head pails,
covers, and components from a selected group or lot. Provided the thermal history of each container is constant, this test method
may be used for determining the applicability of various plastic resins and mold designs for injection molding of open head pails
and covers.
5.2 The environmental stress-crack that occurs is indicative of what results when a container is exposed to agents such as soaps,
organics, or any surface active solutions while under environmental conditions of stress.
5.3 Environmental stress-cracking is a mechanism of chemical attack that is highly dependent upon the test reagent, resin,
container manufacturing or processing history, exposure temperature, applied stress, and other factors. The combination of these
factors may result in eventual stress-crack failure.
5.4 Procedure A minimizes the potential for test variability by providing the user with rigidly defined test conditions. This test
method may be used for production quality control of injection molded open head containers.
5.5 Procedure B allows the user to select and evaluate extreme individual elements or the interaction of several test levels on
container performance. These conditions are established based on laboratory experience and available knowledge of the
distribution environment. This test method may be used for identifying critical stresses which could aid in container design or help
in minimizing the occurrence of these stresses during distribution.
5.6 This test method is intended only as a pass/fail procedure in accordance with the user’s specification, or as agreed upon
between the user and the supplier. It is not intended as a predictor or indicator of field performance regarding time to failure.
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.
D1975 − 21
6. Apparatus
6.1 Environmental Chamber—The environmental chamber should be capable of maintaining a temperature control of 62.5°F
(61.4°C)62.5 °F (61.4 °C) of set point. For best circulation and a constant temperature throughout, a forced air system is
recommended.
6.2 Top Load—Requires a pail identical to the test pail be filled to rated capacity or weight and then nested above the test pail.
Free weights are then placed above in amounts necessary to equal the specified top load. A calibrated pneumatic or hydraulic
cylinder may be substituted for the additional free weights. (Warning—WarningThe—The potential exists for catastrophic
stress-crack failure causing an instability of the applied top load. Precautionary steps should be taken (that is, through restraining
or guiding of the top load) to reduce the chance for injury to the operators or damage to the test chamber and surrounding test
containers.)
7. Reagents
7.1 Procedure A; Nonyl Phenoxypoly (Ethyleneoxy) Ethanol Solution—Prepare a 10 % solution, by volume, of the stress-cracking
agent and water.
NOTE 1—Due to the viscosity of the stress-cracking agent, it is helpful to prepare the solution at an elevated temperature. A maximum temperature of
122°F (50°C)122 °F (50° C) is an acceptable level provided caution is used to avoid prolonged heating and eventual volume losses.
7.2 Procedure B—Any reagent or proprietary product (liquid, solid, etc.) that is potentially a stress-cracking agent.
8. Sampling
8.1 A minimum of three containers are required for this test method. When possible, for direct comparison, the test containers
should be produced on the same equipment, including mold and under identical conditions from the same production lot. It is
suggested that test container resin, machine, mold, and molding conditions be thoroughly documented to improve statistical
reliability of the test data. (Practice E122.)
9. Conditioning
9.1 Condition empty test containers at 7373 °F 6 2°F (23 6 1.3°C) 502 °F (23 °C 6 1.3 °C) 50 % 6 3 % relative humidity for
48 hours 48 h prior to testing (see Practice D4332).
10. Procedure
10.1 Procedure A—Specified Stress-Crack Resistance Method:
10.1.1 Place the environmental chamber set point control at 122122 °F 6 2°F (502 °F (50 °C 6 1.3°C)1.3 °C) and allow it to
reach equilibrium. Fill each test specimen to 98 % of the container’s maximum volumetric capacity (with cover in place) with the
test reagent. Apply the cover to the pail as specified
...