essential human services, especially for those who are least able to help themselves.1 Within HHS, the Food and Drug Administration (FDA) is the agency that is most concerned about corrosion. The FDA is responsible for protecting public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products (including blood, vaccines, and tissues for transplantation), medical devices, the nation’s food supply, cosmetics, and products that emit radiation. The FDA regulates $1 trillion worth of products a year2 and also enforces Section 361 of the Public Health Service Act and associated regulations, including sanitation requirements. Its interest in corrosion concerns issues such as maintaining antiseptic conditions for the manufacture and packaging drugs and for the handling and processing of food products; understanding corrosion products that can leach into the body from materials such as dental amalgams and implanted medical devices; and ensuring the safety of medical equipment such as tanks that hold and dispense medical gases. The FDA issues good guidance practices that set forth statutory and regulatory requirements, such as testing methods to be used to demonstrate capability, that relate to corrosion testing standards.

For example, the FDA addresses concerns about corrosion of implantable medical devices3 through requirements for biocompatibility (i.e., a device’s effect on the body) and biostability (i.e., the body’s effect on a device). Implantable medical devices are becoming increasingly important, given that they can replace a failing heart valve, correct an irregular heart rhythm, replace a worn out hip or knee joint, save a patient from ischemia-induced fibrillation, or even stop the tremors associated with Parkinson’s disease. Companies attempting to secure approval to sell implantable devices must demonstrate both biocompatibility and biostability. Biocompatibility is usually demonstrated by passing standardized tests that meet the guidelines set forth in ISO 10993-Part 1. Materials that corrode probably will not pass these tests because they will cause an inflammatory response or a sensitization reaction. Corrosion is also a major concern for ensuring biostability, which can be assessed in standard laboratory corrosion tests or in vivo from actual experience with implant. Typically, a manufacturer selects a specific type of test and information to submit to the FDA to demonstrate stability of a device in the body; the FDA reviews the data and may approve the submission or require additional data. It is because of these FDA requirements that implantable devices today are made from noncorrosive materials,4 and corrosion is not currently a significant issue.

1

See http://www.hhs.gov/about/.

2

See http://www.fda.gov/RegulatoryInformation/Legislation/default.htm.

3

These devices are implanted in the body for long periods of time, sometimes a decade or more.

4

Materials such as platinum, titanium, silicon rubber, some fluropolymers, and various polyurethanes are among the mainstays in this industry, along with a few exotic nickel-based superalloys. The most “common” material found in implantable medical devices is likely 316 stainless steel. Other than improved wear resistance, there is little driving force for advancing materials in this application.



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