ASTM F703-18(2022)

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: F703 −18 (Reapproved 2022)
Standard Specification for
Implantable Breast Prostheses
ThisstandardisissuedunderthefixeddesignationF703;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope F1251 Terminology Relating to Polymeric Biomaterials in
Medical and Surgical Devices (Withdrawn 2012)
1.1 This specification covers the requirements for silicone
F2038 GuideforSiliconeElastomers,Gels,andFoamsUsed
gel-filled and saline-inflatable silicone gel-filled implantable
in Medical Applications Part I—Formulations and Un-
breast prostheses intended for use in surgical reconstruction,
cured Materials
augmentation, or replacement of the breast.
F2042 GuideforSiliconeElastomers,Gels,andFoamsUsed
1.2 Limitations—This specification does not cover custom
in Medical Applications Part II—Crosslinking and Fabri-
fabricated implantable breast prostheses.
cation
1.3 Single-use saline-inflatable, smooth and textured sili- F2051 Specification for Implantable Saline Filled Breast
Prosthesis
cone shell implantable breast prostheses are addressed in
Specification F2051. 2.2 Other Documents:
Guidance for Industry and FDA Staff Saline, Silicone Gel,
1.4 The values stated in SI units are to be regarded as the
and Alternative Breast Implants, November 17, 2006
standard. The inch-pound units given in parentheses are for
ISO/AAMI/ANSI10993-1 BiologicalEvaluationofMedical
information only.
Devices—Part 1: Evaluation and Testing
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety, health, and environmental practices and deter-
3.1.1 barrier coat, n—a silicone elastomer layer that is part
mine the applicability of regulatory limitations prior to use.
of the shell of a silicone gel implantable breast prosthesis that
1.6 This international standard was developed in accor-
retards silicone bleed.
dance with internationally recognized principles on standard-
3.1.2 fixation site, n—an area of the shell of an implantable
ization established in the Decision on Principles for the
breast prosthesis containing material that allows tissue in-
Development of International Standards, Guides and Recom-
growth.
mendations issued by the World Trade Organization Technical
3.1.3 fused or adhered joints (seams), n—sitesintheshellor
Barriers to Trade (TBT) Committee.
other parts of an implantable breast prosthesis where materials
2. Referenced Documents
havebeenjoined(fusedorbonded)together,withorwithoutan
adhesive, as part of the manufacturing process.
2.1 ASTM Standards:
D412 Test Methods forVulcanized Rubber andThermoplas-
3.1.4 gel bleed, n—diffusion of liquid silicone components
tic Elastomers—Tension
of silicone gel through the shell of an implantable breast
D1349 Practice for Rubber—Standard Conditions for Test-
prosthesis.
ing
3.1.5 gel-filled breast prosthesis, n—implantable breast
F748 PracticeforSelectingGenericBiologicalTestMethods
prosthesis designed and provided with a pre-filled, fixed
for Materials and Devices
volume of silicone gel.
3.1.5.1 Type I breast prosthesis, n—implantable breast pros-
This specification is under the jurisdiction of ASTM Committee F04 on
thesis containing a single lumen containing a fixed amount of
Medical and Surgical Materials and Devices and is the direct responsibility of
Subcommittee F04.32 on Plastic and Reconstructive Surgery.
Current edition approved Oct. 1, 2022. Published October 2022. Originally The last approved version of this historical standard is referenced on
approved in 1981. Last previous edition approved in 2018 as F703 – 18. DOI: www.astm.org.
10.1520/F0703-18R22. Available from U.S. Department of Health and Human Services, Food and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Drug Administration (FDA), 5600 Fishers Ln., Rockville, MD 20857, http://
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.fda.gov/cdrh/ode/guidance/1239.
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F703 − 18 (2022)
silicone gel. or removing saline to or from the prosthesis to increase or
(1) Discussion—The lumen of a Type I breast prosthesis is decrease prosthesis volume.
not accessible for volume adjustments of any kind.
4. Significance and Use
3.1.5.2 Type II breast prosthesis, n—implantable breast
4.1 This specification contains requirements based on state-
prosthesis comprised of two complete lumens, one inside the
of-the-art science and technology as applicable to various
other.
considerations that have been identified as important to ensure
(1) Discussion—The inner lumen of a Type II implantable
reasonable safety and efficacy in implantable breast prostheses.
breast prosthesis contains a fixed amount of silicone gel and is
4.1.1 This specification is not intended to limit the science
not accessible for volume adjustments of any kind. The outer
andtechnologywhichmaybeconsideredandappliedtoensure
lumen is provided with a valve to facilitate filling the void
performance characteristics of breast prostheses in intended
between the inner and outer lumens with saline to adjust the
applications. When new information becomes available or
total volume of the prosthesis at the time of use. The valve
changes in state-of-the-art science and technology occur and
system may also be designed to facilitate postoperative saline
relevance to prostheses has been established by valid science,
volume adjustment by following the instructions provided in
it is intended that this specification will be revised in keeping
the product literature.
with the new information or advances in state-of-the-art
3.1.5.3 Type III breast prosthesis, n—implantable breast
science.
prosthesis comprised of two complete lumens, one inside the
other.
5. Materials and Manufacture
(1) Discussion—The area between the inner and outer
5.1 Silicone Elastomer—Select and specify elastomers for
lumens contains a fixed amount of silicone gel and is not
use in implantable breast prostheses in keeping with Guides
accessible for volume adjustments of any kind. The inner
F2038 and F2042.
lumen is contained within the silicone gel contained in the
5.1.1 Fabrication—Fabrication techniques must necessarily
outerlumenandhasavalvesystemtofacilitatefillingtheinner
be varied depending on the type of elastomer, the portion of an
lumen with saline to increase the volume of the prosthesis at
implantable breast prosthesis fabricated, its shape and its
the time of use. The valve system may also be designed to
location, and function on the prosthesis.
facilitate postoperative saline volume adjustment by following
5.1.2 Vulcanization and Postcure—Time and temperature of
the instructions provided in product literature.
vulcanizationandpostcuremustbeadjustedwithconsideration
3.1.6 low bleed, n—silicone gel implantable breast prosthe-
of the elastomer type and the multi-step fabrication require-
ses designed to have minimal silicone bleed when tested using
ments of specific prostheses. Final postcure is typically done
the test method in 9.2.1.
only after the shell or shells and all other portions have been
completely assembled. Time and temperature of final postcure
3.1.7 lumen, n—a cavity within a shell of an implantable
shall be adequate to drive the chemistry of vulcanization of all
breast prosthesis.
elastomers to completion and remove by-products of the cure
3.1.7.1 Discussion—A lumen may contain either a fixed,
in keeping with the chemical stoichiometry of the specific cure
non-adjustable volume of silicone gel, or it may be entirely or
systems (for example, after postcure no additional vulcaniza-
partly empty and intended to be inflated (filled) with saline.
tion should occur when heated additionally at the recom-
Inflatable lumens are accessible by valve to facilitate the
mended cure temperature).
addition of saline to adjust the volume of the prosthesis at the
timeofuse.Morethanonelumenmaybeformedwithinashell
5.2 Silicone Gel—Select and specify ingredients in keeping
by silicone elastomer membrane partitions.
with Guides F2038 and F2042.
5.2.1 Fabrication, Vulcanization, and Postcure:
3.1.8 orientation means, n—anymarkorpalpableportionof
5.2.1.1 Fabrication and Curing—Unvulcanized liquid gel is
an implantable breast prosthesis to assist the surgeon in
typicallyplacedinthelumenofashellandcuredandpostcured
positioning the implant.
in situ while the shell is maintained in its desired final shape.
3.1.9 saline, n—sodium chloride injection USP.
Fabrication techniques must necessarily be varied to satisfy the
requirements of the specific implant type and shape.
3.1.10 shell, n—a silicone elastomer continuous layer or
membrane container (sac) that encloses a lumen or multiple 5.2.1.2 Vulcanization and Postcure—The time and tempera-
ture of vulcanization and postcure shall be adequate to drive
lumens of an implantable breast prosthesis.
thevulcanizationchemistryofthegeltocompletioninkeeping
3.1.11 silicone elastomer, n—an elastomer containing cross-
withthechemicalstoichiometryofspecificsiliconegels.When
linked silicone polymer and fumed amorphous (non-
postcure is adequate, silicone gel does not undergo further
crystalline) silica as a reinforcing filler.
vulcanization with additional heating at the cure temperature.
3.1.12 silicone gel, n—a semisolid material consisting of a
crosslinked silicone polymer network in which liquid silicone 6. Volume and Dimensions
polymer is held (see definition of gel in Terminology F1251).
6.1 Volumes of Prostheses:
3.1.13 valve, n—user-sealable or self-sealing opening in an 6.1.1 Silicone Gel and Gel-Saline Prostheses—Because sili-
inflatable or gel saline prosthesis, extending from the exterior cone gel has a specific gravity of approximately one, volumes
surface of the shell into a lumen, designed to facilitate adding ofsiliconegel-containingprosthesesaretypicallycontrolledby
F703 − 18 (2022)
weight. 1 g = approximately 1 cm . The weight tolerance of a 9.1.3 Prior Biocompatibility Assays—When prior biocom-
silicone gel-containing prosthesis with volume ≥250 cm shall patibilitydataareavailableforsiliconeelastomersandgelsthat
be 65 g. The weight tolerance of a silicone gel-containing may also have histories of clinical use in breast implants, even
prosthesis with volume <250 cm shall be 62 % of labeled if not done by the exact protocols described in more recently
volume in equivalent grams. developed biocompatibility test method standards, such data
6.1.2 Gel-Saline Prostheses—The design or maximum rec- may satisfy all or part of the specific biocompatibility require-
ommended volume of saline fill shall be listed in the labeling. ments of Practice F748 or equivalent methodology.
6.2 Dimensions—Therangesofshapes,volumes,basesizes,
9.2 Physical Properties:
and anterior projections shall be determined by the manufac-
9.2.1 Test Procedure—Siliconeprosthesesshalldemonstrate
turer. Pertinent information shall be contained in the labeling.
an acceptable response in physical property tests. Prostheses
for testing should be selected from standard production
7. Fixation Sites
batches, or equivalent, which have gone through all manufac-
7.1 Fixation sites shall be optional features on a silicone gel turing processes, including sterilization. Unless otherwise
implantable breast prosthesis. When used, the size and loca- specified, the standard temperature for testing shall be 23 6
tions of fixation sites shall be clearly stated in the labeling. 2 °C (73.4 6 3.6 °F). When testing at any other temperature is
required, one of the temperatures specified in Practice D1349
8. Orientation Means shall be used. Requirements are as follows:
9.2.1.1 Shell Test Method—Cut the test specimens from
8.1 Orientation means shall be optional features on a sili-
units made from standard production batches, or equivalent,
cone gel implantable breast prosthesis. When orientation
which have gone through all manufacturing processes, includ-
means are claimed, the location and recommended techniques
ing sterilization. With silicone gel prostheses, remove gel and
for use shall be clearly described in the labeling.
clean shell with appropriate polar (for example, 2-propanol) or
nonpolar (aliphatic, aromatic, or chlorinated hydrocarbon)
9. Test Methods and Requirements
solvent, or both. If solvent cleaned, condition shell afterwards
9.1 Biocompatibility:
for3hat150°F (65.6 °C) in an air circulation oven to remove
9.1.1 Practice F748—New or existing materials shall be in
solvent. Test shells shall be wiped clean (not soaked or
compliance with Practice F748 or other acceptable standards
submerged) using lint-free tissue and isopropyl alcohol, then
such as ISO/AAMI/ANSI 10993-1. Biocompatibility assays of
left to dry at room temperature for at least 2 h. Cut required
materials with no or limited history of prior biocompatibility
tensile test dumbbell specimens from shells with Test Methods
testingandsuccessfulclinicaluseforimplantapplicationsshall
D412dies.Specimensshallbeconditionedbeforetestingforat
follow guidelines of Practice F748. Assays recommended by
least3hat23 6 2 °C (73.4 6 3.6 °F).
Practice F748 include cell culture cytotoxicity assays; short-
(1) Percent Elongation—Percent elongation shall be
term intramuscular implantation assay; short-term subcutane-
≥350 % when tested in accordance with Test Methods D412,
ous assay; carcinogenicity; long-term implant test; systemic
Die C.
injection (acute toxicity) assay; sensitization assay; mutagen-
(2) Breaking Strength—The ultimate breaking force shall
icity; and pyrogenicity.
be not less than 11.12 N (2.5 lb) when tested in accordance
9.1.2 Silicone Gel Prostheses—Test specimens for chronic
with Test Methods D412, Die C.
implantation assays (carcinogenicity and long-term implant
(3) Tensile Set—To determine tensile set at 300 %
tests)shallbefabricatedfromthesamecombinationofsilicone
elongation, stress the specimen for 3 min then allow 3 min for
elastomer and gel and by the same or similar procedures and
relaxation. The tensile set shall be <10 %, as determined in
conditions used in fabricating prostheses. The thickness of the
accordance with Test Methods D412.
shell in specimens shall be typical of the thickness used in
(4) Critical Fused or Adhered Joints—Joints or seams that
prostheses.
are critical to the integrity of the prosthesis envelope shall not
NOTE 1—To minimize palpability of prostheses and to effectively fail when the shell adjacent to the joint is stressed to 200 %
mimicthesoftnessofbreasttissue,siliconegelsusedinimplantablebreast
elongation for 10 s (see Fig. 1).
prostheses must be soft (have low modulus). State-of-the-art silicone gels
(5) Noncritical Fused or Adhered Joints—Fused joints or
with required low modulus are also low strength. When implanted long
seams that are bonded to the prosthesis envelope but are not
term without an enclosing silicone elastomer shell, silicone gel may not
critical to the envelope integrity (fixation sites, orientation
retain its physical shape and integrity. Clinical implantation of free
silicone gel sans shell is neither intended nor recommended. If shell
means, valve covers, and so forth) shall not fail when the shell
rupture occurs in an implanted silicone gel breast prosthesis, resulting in
adjacent to the joint is stressed to 100 % elongation for 10 s
direct contact between silicone gel and tissue, surgery for removal of the
(see Fig. 1).
ruptured prosthesis (with or without prosthetic replacement) and any free
(6) Shell Rupture/Failure Testing—No standard test for
gel is recommended. To help ensure relevancy of long-term biocompat-
ibility assays in animals to recommended clinical use of silicone gel assessing shell rupture/failure has yet been developed. When
implantable breast prostheses, the specimens used in chronic biocompat-
such test method has been developed it will be added to this
ibility assays shall have silicone gel contained in an enclosing silicone
specification.
elastomer shell, similar to silicone gel prostheses. Specimens of free
(7) Shell Leakage Testing for Type II and Type III
silicone gel may be used in all other biocompatibility assays as specified
Devices—Filla5to8qt stainless steel bowl with 70 %
in Practice F748 for implants used in tissue and tissue fluid contact
applications, including short-term intramuscular implantation assay. isopropyl alcohol. Submerge patched shell in bowl and gently
F703 − 18 (2022)
FIG. 1 Testing Fused or Adhered Joints
NOTE 2—The test results from cone/pendant gel testing are highly
apply pressure to the shell assembly. Visually inspect for any
dependent on strict adherence to the specifications for the test apparatus
bubbles. Reposition shell in hand until entire surface of shell
andtheproceduresdescribedinAnnexA1.Precisionandbiasdataforthis
has been tested while exposed. Reject shells whenever any
method have not been established.
bubbles are seen.
NOTE 3—With firmer more cohesive gels, a manufacturer may deter-
9.2.1.2 Valve Competence Test Method for Type II and Type
mine that an alternative test method, through an appropriate correlation
study, may satisfy this gel cohesion test method to demonstrate equivalent
III Devices—Prior to testing, manipulate valve to duplicate its
or better cohesiveness and the no gel separation requirement.
use for filling an inflatable lumen with saline as described in
instructions for use. Test the valve at both high and low
9.2.1.5 Gel Bleed Test Method—See Annex A2.
retrograde pressures. Use air, distilled water, or isotonic saline
(1) Requirements—Theallowablequantitiesofgelbleedin
as the test medium. Pressures in the order to be tested are
this testing have not been established.
30 cm and 3 cm H O pressure, respectively. Maintain each test
pressurefor5min.Whenairisthetestmedium,immersevalve
10. Other Test Methods
opening in water to check for leakage (bubbles). With water or
10.1 Additional specific tests, as described in the FDA
isotonic saline as the test medium, check for droplets at the
guidance document, should be addressed.
valve opening.
(1) Test Requirements—No observable or detectable leak- 10.2 Gel Penetration Test Method Described in
age. Annex A3—This in-process test is particularly useful to manu-
9.2.1.3 Silicone Gel Test Method—Remove test samples of
facturers for use in silicone gel development and quality
gel from finished production batches of silicone gel-containing control in that it provides quantitative results. This test method
implantable breast prostheses after all manufacturing, includ- isusedtocharacterizethefirmnessofverysoftgelandresilient
ing sterilization, has been completed. gel and is a way a manufacturer can ensure the gel mixing
(1) Weight L
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