The products in the pharmaceutical industry are wanted products. This is a reason the purity requirements are really high. The sealing solution needs to have an solution for to prevent contamination with the product.
There are a lot of applications and processes. They all have individual requirements. Finished pharmaceuticals need to have good medical resistance of sealing materials. This is to go against various educts and solvents. When producing vaccines, proteins and the separation of blood there is a change of low temperatures. Because of this their need to be hygienic seals that can resist cold temperatures.
Before an O-ring is approved for the Pharmaceutical industry it first needs to be tested. It needs to be test for cytotoxicity. Cultures of these cells are produced in glass flasks prior to testing. Extracts are prepared using 3 test articles: the O-ring material, a negative control article (HDPE), and a positive control article (PVC for USP <87>, and powder-free latex gloves for ISO 10993-5). These extracts are then added to the cell cultures. Cells are incubated with the extracts and then examined after 48 hours.