Bacterial endotoxins are one of the most active toxins recognized and highly pyrogenic (fever-causing) substances located on the outer cell membrane of Gram-negative species. Outside the body and in the feeding canal, these toxins are harmless. However, they are extremely potent once incorporated into the bloodstream or intrathecally. In nature, bacterial endotoxins are prevalent and are a threat to manufacturers of all parenteral drugs and medical devices. They are not only environmentally present everywhere, but they are also difficult to extract once they are inserted into a finished parenteral product. The endotoxin testing is done by a different type of tests which includes the Limulus Amoebocyte Lysate (LAL) Test, Monocyte Activation Test (MAT), Rabbit Pyrogen Test, and Recombinant C (RFC) Assay.