ASTM F641-09(2023) PDF

ABSTRACT This specification covers thermoset plastics based on diglycidyl ethers of bisphenol A and amino functional curing agents or amine catalysts for implantable epoxy electronic encapsulants. Encapsulants shall be classified depending on contact with tissues or physiological fluids. Chemical composition requirements may include additives, phthalate esters, amines, catalysts, and carbonates. The material shall be tested for the following physical properties: peak exotherm temperature, transparency, foreign particles, USP biological test plastic containers, USP pyrogen test, sterilant residues, cure shrinkage, embedment stress, tissue culture test, long-term immersion test, and accelerated immersion test. The material shall also be inspected with infrared spectroscopy, amine number, epoxide equivalent weight, spectrographic analysis, and total nitrogen. SCOPE 1.1 This specification covers thermoset plastics based on diglycidyl ethers of bisphenol A and amino functional curing agents or amine catalysts. 1.2 The epoxy encapsulants covered by this specification are intended to provide a tissue-compatible protective covering for implantable medical devices such as pulse generators, telemetry devices, and RF receivers. The biocompatibility of epoxy plastics has not been established. Epoxy plastic is a generic term relating to the class of polymers formed from epoxy resins, certain curing agents or catalysts, and various additives. Since many compositions and formulations fall under this category, it is essential that the fabricator ensure safety of implantability of the specific composition or formulation for the intended use by current state-of-the-art test methods. This specification can be used as a basis for standardized evaluation of biocompatibility for such implantable encapsulants. 1.3 The encapsulants covered by this specification are for use in devices intended as long-term implants. 1.4 Limitations—This specification covers only the initial qualification of epoxy encapsulants for implantable electronic circuitry. Some of the requirements are not applicable to routine lot-to-lot quality control. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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. 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.