ASTM F2695-12(2020)

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:F2695 −12 (Reapproved 2020)
Standard Specification for
Ultra-High Molecular Weight Polyethylene Powder Blended
With Alpha-Tocopherol (Vitamin E) and Fabricated Forms for
Surgical Implant Applications
This standard is issued under the fixed designation F2695; 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 2. Referenced Documents
1.1 This specification covers ultra-high molecular weight 2.1 ASTM Standards:
polyethylene (UHMWPE) powder blended with alpha- D648 Test Method for Deflection Temperature of Plastics
tocopherol (Vitamin E) intended for use in surgical implants. Under Flexural Load in the Edgewise Position
D790 Test Methods for Flexural Properties of Unreinforced
1.2 The requirements of this specification apply to alpha-
and Reinforced Plastics and Electrical Insulating Materi-
tocopherol-containing UHMWPE in two forms. One is virgin
als
polymer powder blended with alpha-tocopherol prior to con-
D1898 Practice for Sampling of Plastics (Withdrawn 1998)
solidation (Section 4). The second is any form fabricated from
D4020 SpecificationforUltra-High-Molecular-WeightPoly-
this blended, alpha-tocopherol-containing powder from which
ethylene Molding and Extrusion Materials
a finished product is subsequently produced (Section 5). This
F619 Practice for Extraction of Materials Used in Medical
specification does not apply to finished or semi-finished
Devices
products that are doped with Vitamin E after consolidation.
F648 Specification for Ultra-High-Molecular-Weight Poly-
1.3 Aside from blending with alpha-tocopherol, the provi-
ethylene Powder and Fabricated Form for Surgical Im-
sions of Specifications F648 and D4020 apply. Special require-
plants
ments detailed in this specification are added to describe
F748 PracticeforSelectingGenericBiologicalTestMethods
powders containing alpha-tocopherol that will be used in
for Materials and Devices
surgical implants. This specification addresses material char-
F749 Practice for Evaluating Material Extracts by Intracuta-
acteristics and does not apply to the packaged and sterilized
neous Injection in the Rabbit
finished implant. This specification also does not apply to
F756 Practice for Assessment of Hemolytic Properties of
UHMWPE materials extensively crosslinked by gamma and
Materials
electron beam sources of ionizing radiation.
F763 Practice for Short-Term Screening of Implant Materi-
1.4 The following precautionary caveat pertains only to the als
fabricated forms portion, Section 5, of this specification. This
F813 Practice for Direct Contact Cell Culture Evaluation of
standard does not purport to address all of the safety concerns, Materials for Medical Devices
if any, associated with its use. It is the responsibility of the user
F895 TestMethodforAgarDiffusionCellCultureScreening
of this standard to establish appropriate safety, health, and for Cytotoxicity
environmental practices and determine the applicability of
F981 Practice for Assessment of Compatibility of Biomate-
regulatory limitations prior to use. rials for Surgical Implants with Respect to Effect of
1.5 This international standard was developed in accor-
Materials on Muscle and Insertion into Bone
dance with internationally recognized principles on standard-
2.2 ISO Standards:
ization established in the Decision on Principles for the
ISO3451–1 Plastics—DeterminationofAsh,Part1:General
Development of International Standards, Guides and Recom-
Methods
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This specification is under the jurisdiction of ASTM Committee F04 on Standards volume information, refer to the standard’s Document Summary page on
Medical and Surgical Materials and Devices and is the direct responsibility of the ASTM website.
Subcommittee F04.11 on Polymeric Materials. The last approved version of this historical standard is referenced on
Current edition approved Nov. 15, 2020. Published November 2020. Originally www.astm.org.
approved in 2007. Last previous edition approved in 2012 as F2695 – 12. DOI: Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/F2695-12R20. 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
F2695−12 (2020)
ISO 10993 Biological Evaluation of Medical Devices, Parts 4.3.1.2 When measured based on agreement between the
1–12 vendor and purchaser, the alpha-tocopherol content added to
the powder shall be reported in units of ppm and percent mass.
3. Terminology 4.3.1.3 Uniformity of the alpha-tocopherol in the blended
powder shall be measured based on agreement between the
3.1 Definitions of Terms Specific to This Standard:
vendor and the purchaser.
3.1.1 crosslinking—the process by which ionizing irradia-
4.3.1.4 No other stabilizers or processing aids are to be
tion produces chemical bonds between UHMWPE molecules.
added to the virgin polymer powder.
3.1.2 extensively crosslinked UHMWPE—UHMWPE mate-
rial that has been subjected to total doses of gamma and/or
5. Alpha-Tocopherol-Blended UHMWPE Fabricated
electron beam ionizing irradiation greater than 40 kGy. Form Requirements
3.1.3 fabricated form—any bulk shape of UHMWPE, fab-
5.1 Compositional Requirements:
ricated from the virgin polymer powder, used during the
5.1.1 Only alpha-tocopherol-blended powder, specified in
process of fabricating surgical implants prior to crosslinking,
Section 4, is to be used to produce the fabricated form.
packaging, and sterilization. A fabricated form includes a
5.1.1.1 The alpha-tocopherol content in the fabricated form
semi-finished rod or sheet as well as a direct compression
may be based on agreement between the vendor and purchaser.
molded component.
5.1.1.2 When measured based on agreement between the
vendor and purchaser, the alpha-tocopherol content used to
3.1.4 generic property—that property which is determined
produce the fabricated form shall be reported in units of ppm
solely by the chemical composition and structure of the virgin
and percent mass.
polymer.
5.1.2 Uniformity of the alpha-tocopherol in the fabricated
3.1.5 ionizing irradiation—gamma ray or high-energy elec-
form shall be measured based on agreement between the
tron irradiation sources.
vendor and the purchaser.
3.1.6 virgin polymer powder—theinitiallydeliveredformof 5.1.3 No other stabilizers or processing aids are to be added
the polymer as synthesized from its monomers prior to any
tothealpha-tocopherol-blendedpolymerpowderduringmanu-
processing or fabrication into a medical device. The provided
facture of the fabricated form.
resinistypicallyintheformofpellets,granules,orpowderand
5.2 Physical Requirements:
is the material from which fibers, tubes, rods, slabs, sheets,
5.2.1 Foreign Matter Requirements:
films, or specific parts and devices are fabricated. Specifically,
5.2.1.1 When 3200 cm is evaluated according to section
it is the form of UHMWPE as obtained from the powder
7.2.2 of Specification F648, there shall be no more than ten
manufacturer and prior to blending and fabrication into a bulk
particles of extraneous matter visible on the surface when
shape.
visually inspected by normal or corrected vision.
5.2.2 Morphology Requirements:
4. Alpha-Tocopherol-Blended UHMWPE Powder
5.2.2.1 When evaluated according to Annex 2 of Specifica-
Requirements
tion F648, the calculated Morphology Index (MI) shall be
4.1 Generic Properties: reported.
4.1.1 The virgin polymer shall be a homopolymer of ethyl-
5.3 Mechanical Requirements:
ene in accordance with Specification D4020.
5.3.1 UHMWPE in fabricated form from which implants
4.1.2 The resin type and solution viscosity number require-
shall be made shall meet the requirements listed in Table 2 of
ments are listed in Table 1 of Specification F648.
Specification F648.
4.1.3 To promote uniformity between different lots of the
5.3.2 The following mechanical tests may be conducted
virgin polymer powder, concentration limits for trace elements
based on agreement between the vendor and purchaser: (1)
have been established and are listed in Table 1 of Specification
deflection temperature; Test Method D648 (1.8 MPa); (2)
F648.
flexural modulus; Test Methods D790 (secant, 2 % offset).
4.1.4 When determined as described in ISO 3451–1, the
6. Sampling
mean ash of duplicate samples shall not exceed the limits
established in Table 1 of Specification F648.
6.1 Where applicable, the requirements of this specification
shall be determined for each lot of powder and fabricated form
4.2 Nongeneric Properties:
bysamplingsizesandproceduresaccordingtoPracticeD1898,
4.2.1 When a 300 g sample is prepared and viewed in
or as agreed upon between the purchaser and seller.
accordancewithsection7.1.2ofSpecificationF648,thereshall
be no more particles of extraneous matter than that specified in
7. Biocompatibility
Table 1 of Specification F648.
7.1 No known surgical implant material has ever been
4.3 Compositional Requirements:
shown to be completely free of adverse reactions in the human
4.3.1 Only alpha-tocopherol (certified pharmaceutical
grade) is to be blended w
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