Biological evaluation plan is more than just testing to the grid.
                Should include published literature and vendor literature
                Should include qualifications
                Should include plans for review and approval of the plan
                Should include plans for review and approval of conclusions
Should include plans for mitigating measures to reduce risk and acceptable risks as well as labeling claims or exceptions.
Manufacturing process effects
It is no longer about just the materials anymore.  It is now what do your processes do to this “historically used” material.  Testing something that hasn’t gone through the same processes in inadequate.  Physical processes such as heat, sterilization, welding, and machining.   Additives and processing aids, such as catalysts, coatings, pigments.  Contaminants from cleaning, lubrication, release agents.  Finally, degradation and storage
Testing is to start with chemical and then proceed to in vitro before embarking on animal testing.
Long term testing such as chronic, reproductive toxicity, degradation and carcinogenicity require justification to run and also need justification not to run.
When a device has the identical chemical composition and physical properties as the same contact and application as a device that has clinical data that addresses biocompatibility endpoints then a materials characterization can be used to address the biological safety.