ISO 19671:2018

Additional lubricants for male natural rubber latex condoms -- Effect on condom strength

This document specifies a method of assessing the effect or compatibility of an additional or personal lubricant with lubricated male natural rubber latex condoms. It also applies to topical medicines and any other substances that come into contact with such condoms. It describes the measurement of changes in physical properties of the condoms after exposure to the test substance (i.e. lubricant, topical medicine, etc.) and specifies the pass/fail criteria for such changes. This document is not applicable to the assessment of the compatibility of lubricants applied to a condom at the time of manufacture. It is not directly applicable to the assessment of the compatibility of a particular condom with lubricants or other substances. It is not directly applicable to tests using female condoms, although similar principles can apply. The test methods are applicable to condoms made from natural rubber latex and from synthetic materials, but a pass/fail criterion is only stipulated for natural rubber latex.

Lubrifiants supplémentaires pour préservatifs masculins en latex de caoutchouc naturel -- Effet sur la résistance du préservatif

General Information

• Status: Published
• Publication Date: 30-Oct-2018
• ICS: 11.200 - Birth control. Mechanical contraceptives
• Technical Committee: ISO/TC 157 - Non-systemic contraceptives and STI barrier prophylactics
• Drafting Committee: ISO/TC 157/WG 15 - Additional lubricants
• Current Stage: 6060 - International Standard published
• Start Date: 30-Sep-2018
• Completion Date: 31-Oct-2018

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 19671
First edition
2018-11
Corrected version
2020-02
Additional lubricants for male natural
rubber latex condoms — Effect on
condom strength
Lubrifiants supplémentaires pour préservatifs masculins en latex de
caoutchouc naturel — Effet sur la résistance du préservatif
Reference number
ISO 19671:2018(E)
ISO 2018
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ISO 19671:2018(E)
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© ISO 2018

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ii © ISO 2018 – All rights reserved
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ISO 19671:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 2

5 Apparatus ..................................................................................................................................................................................................................... 2

6 Materials ....................................................................................................................................................................................................................... 3

7 Samples and tests ................................................................................................................................................................................................ 3

7.1 Sample overview ................................................................................................................................................................................... 3

7.2 Condom sample groups ................................................................................................................................................................... 4

7.3 Sample size ................................................................................................................................................................................................. 4

7.4 Quantity of test substance ............................................................................................................................................................. 4

7.4.1 Inflation testing ................................................................................................................................................................. 4

7.4.2 Tensile testing .................................................................................................................................................................... 4

8 Procedure..................................................................................................................................................................................................................... 4

8.1 General ........................................................................................................................................................................................................... 4

8.2 (Negative) control testing .............................................................................................................................................................. 5

8.3 Inflation testing ...................................................................................................................................................................................... 5

8.4 Tensile testing .......................................................................................................................................................................................... 5

9 Positive control testing .................................................................................................................................................................................. 6

10 Pass/Fail criteria .................................................................................................................................................................................................. 6

11 Expression of results ........................................................................................................................................................................................ 8

Annex A (normative) Determination of force and elongation at break of test pieces of condoms ......9

Annex B (informative) Determination of the confidence interval for the ratio of two means...............12

Bibliography .............................................................................................................................................................................................................................15

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ISO 19671:2018(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 157, Non-systemic contraceptives and STI

barrier prophylactics.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 19671:2018 incorporates the following corrections:
— specifications for viscosity and specific gravity of positive control in 6.2;

— specifications for viscosity and specific gravity of positive control in Clause 9;

— “test substance” has been replaced by “lubricant” in A.3.3;
— subscript in Formula (B.4).
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ISO 19671:2018(E)
Introduction

Weakening of natural rubber latex is known to occur after contact with certain lubricants, particularly

petroleum-based products. This procedure was developed as a screening method for lubricant

manufacturers to determine whether or not a particular personal lubricant or topical medicine has

a significant effect on the tensile and airburst properties of condoms. It is also applicable to topical

medicines and other chemicals that might come in contact with vulval, vaginal or rectal tissues, and

hence with condoms.

The method is designed for use on male condoms that meet the criteria of ISO 4074. While the test

method can be effective for male condoms made of other raw materials, there is no evidence upon

which to base pass/fail criteria for these materials.

This test method does not determine the safety of either the test substance or the condom.

This test method is to be used only to determine if the tensile or airburst properties of the condom have

been significantly affected by the test substance.
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INTERNATIONAL STANDARD ISO 19671:2018(E)
Additional lubricants for male natural rubber latex
condoms — Effect on condom strength
1 Scope

This document specifies a method of assessing the effect or compatibility of an additional or personal

lubricant with lubricated male natural rubber latex condoms. It also applies to topical medicines

and any other substances that come into contact with such condoms. It describes the measurement

of changes in physical properties of the condoms after exposure to the test substance (i.e. lubricant,

topical medicine, etc.) and specifies the pass/fail criteria for such changes.

This document is not applicable to the assessment of the compatibility of lubricants applied to a condom

at the time of manufacture. It is not directly applicable to the assessment of the compatibility of a

particular condom with lubricants or other substances. It is not directly applicable to tests using female

condoms, although similar principles can apply.

The test methods are applicable to condoms made from natural rubber latex and from synthetic

materials, but a pass/fail criterion is only stipulated for natural rubber latex.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 4074:2015, Natural rubber latex male condoms — Requirements and test methods
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 4074 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
personal lubricant

additional lubricant intended for application by the user at the time of condom use

3.2
positive control

test substance (3.3) which is known to cause deterioration in the physical properties of a condom

3.3
test substance

lubricant (3.1), topical medicine (3.4) or other material which is being tested for compatibility with

condoms
3.4
topical medicine

medicine intended to be used vaginally or rectally, and which might come into contact with a

condom in use
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ISO 19671:2018(E)
4 Principle

This test method measures the change in tensile properties and inflation properties of condoms, after

60 min of contact with a lubricant or other test substance to which this document refers. Force at break

is the principal and most sensitive variable used in assessing the effect of test substances.

For tensile testing, rings cut from condoms are exposed to the test substance, heated to body

temperature, cleaned of excess test substance, and tested for force at break and percent elongation at

break in accordance with Annex A. Those properties are compared to control rings that are subjected

to the same procedures using distilled water instead of the test substance.

For inflation testing, the parts of the condoms which are subject to inflation are exposed to the test

substance and are then heated to body temperature. They are then subjected to inflation testing as

prescribed in ISO 4074 or ISO 23409. The results are compared to control condoms that are subjected

to the same using distilled water instead of the test substance.
5 Apparatus
5.1 Environmental chamber or oven, capable of maintaining (40 ± 2) °C.

5.2 Specimen containers for inflation testing, capable of holding one condom and sealing volatile

components of the test substance, so they cannot escape into the atmosphere. The excess space in the

container should be kept to a minimum.
NOTE A glass jar is a suitable container.

5.3 Specimen containers for tensile testing, capable of holding one tensile sample and sealing

volatile components of the test substance, so they cannot escape into the atmosphere. The excess space

in the container should be kept to a minimum.
NOTE A glass jar is a suitable container.

5.4 Tensile tester and roller grips, capable of testing ring specimens according to Annex A.

5.5 Ring-cutting die, mechanical press, and replaceable cutting surface, for cutting ring specimens

from condoms, compliant with Annex A.

5.6 Mounts, suitable for holding ring samples while they are being coated with test substance. These

mounts may be two cylindrical rollers about 15 mm in diameter, placed with their axes about 50 mm

apart, over which the samples are stretched. Refer to Annex A.

5.7 Soft paintbrush, suitable for spreading the test substance on the condoms. A width of

approximately 10 mm and thickness 5 mm to 10 mm, is recommended.

5.8 Cylindrical mounts, suitable for coating and storing condom samples for inflation testing. These

can be glass test tubes 32 mm to 38 mm in diameter, or plastic rods with approximately hemispherical

ends, mounted in such a way that the condoms can easily be unrolled onto them.

NOTE The tubes are intended to produce a smooth condom surface for applying the test substance, and also

to allow easy removal of the condom after coating. The dimensions are not critical.

5.9 Inflation tester, suitable for testing condoms in accordance with ISO 4074:2015, Annex H.

5.10 Syringes or pipettes, for dosing 1,5 ml and 0,2 ml of the substance under test.

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ISO 19671:2018(E)

5.11 Small beaker or cylindrical container, about 30 mm in diameter, for storing the test substance

and for moistening paintbrushes.
6 Materials

6.1 Condoms, complying with ISO 4074, to which the test substance is applied. The condoms shall

be smooth and parallel-sided. The mean thickness of the condoms used, when measured according to

ISO 4074 shall be between 0,055 mm and 0,07 mm. The mean force at break of the negative control

condoms shall be between 70 N and 100 N.

6.2 Liquid paraffin, for positive control testing, meeting the current requirements of the US, European

or British pharmacopeia, with a specific gravity of 0,83 to 0,85 at (25 ± 2) °C, and a kinematic viscosity

-5 2 -5 2

of 4·10 m /s to 5·10 m /s at 40 °C. The liquid paraffin is expected to cause significant degradation in

natural rubber condom physical properties when the test method is properly performed.

6.3 Cyclomethicone D5, for positive control testing, meeting the current requirements of the US,

European or British pharmacopeia. The cyclomethicone D5 is expected to cause significant reversible,

short-term degradation in natural rubber condom physical properties when the test method is properly

performed.
6.4 Distilled water, for negative control testing.

6.5 Solvents, including water, isopropanol (IPA), and mild detergent, for cleaning laboratory

equipment and supplies after each test substance group has been tested.

6.6 Cornstarch, or similar inert powder, to assist in dimensional measurements and tensile testing

(optional).

6.7 Low-lint laboratory-grade paper towels, for removing test substance from test samples after

oven conditioning.
7 Samples and tests
7.1 Sample overview

7.1.1 This test method shall be performed on three distinct, commercially available natural latex

condoms made in different factories and belonging to different independent companies. The products

shall be chosen from among leading brands in the country or countries where the test result is to be

applied or, in the case of internationally branded products, three major international brands. The mean

thickness for each product as determined in accordance with ISO 4074 shall be in the range 0,055 mm to

0,07 mm.

7.1.2 Each brand of condom should be lubricated, straight-walled, smooth condoms from a single

finished lot.
7.1.3 All natural rubber latex condoms shall meet the requirements of ISO 4074.

It is acceptable to purchase condoms that are stated to conform to ISO 4074 from retail outlets or

wholesalers.
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ISO 19671:2018(E)
7.2 Condom sample groups

7.2.1 Each of the three distinct brands of condoms shall be divided into two groups and tested for

physical properties in the following order:

a) Control group: Condoms are tested according to 8.3 and 8.4, but the tensile samples/condoms

are lubricated with distilled water. All other handling and testing of the control tensile samples/

condoms shall be exactly the same as for the test substance group. There is no contact with the test

substance in the control group.

b) Test substance group: Condoms are tested in accordance with Clauses 8 and 9 with a substance for

which condom compatibility is unknown.

7.2.2 For staff training and for periodic re-validation of the method, a third group of products exposed

to a positive control (with short or long-term effects) shall be tested, either instead of or after, the test

substance group.
7.3 Sample size
The sample size for tensile testing shall not be less than 30 condoms per group.
7.4 Quantity of test substance
7.4.1 Inflation testing
a) Lubricants: Each condom shall be exposed to (1,5 ± 0,15) ml of lubricant.

b) Topical medicines: Each condom shall be exposed to one normal dose of the medicine. Where

necessary to achieve even spreading over the sample, the medicine may be dissolved or dispersed

in a minimum quantity of distilled water at a temperature of up to 45 °C prior to application.

7.4.2 Tensile testing

a) Lubricants: Each ring sample shall be exposed to (0,2 ± 0,02) ml of lubricant.

b) Topical medicines: Each ring sample shall be exposed to (12 ± 1) % of one normal dose of the

medicine. Where necessary to achieve even spreading over the sample, the medicine may be

dissolved or dispersed in a minimum quantity of distilled water at a temperature of up to 45 °C

prior to application.
8 Procedure
8.1 General

The negative control test shall be performed first, and be followed immediately by the test on the

test substance. Additional substances may be tested thereafter, provided all equipment is thoroughly

cleaned of the previous test substance beforehand. Provision is made for testing positive controls,

liquid paraffin and cyclomethicone D5, to train operators and validate techniques.

NOTE Some regulatory bodies might require positive control results to be submitted along with the results

for the test substances.

Tests performed using natural latex condoms shall apply to claims of compatibility with natural latex

condoms only.
Tensile testing shall be conducted in accordance with Annex A.
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ISO 19671:2018(E)
8.2 (Negative) control testing

For both inflation and tensile testing, a control test shall be conducted immedia

...