An endotoxin is a lipopolysaccharide (LPS) found in the cell mass of gram-negative microscopic organisms. It is an ordinary pyrogen, which initiates different organic responses when even a limited quantity of pg (10-12 g) or ng (10-9 g) enters the circulatory system. Because of its warmth obstruction and solidness, complete inactivation of endotoxin is beyond the realm of imagination with autoclaving. Dry warmth sanitization for at any rate 30 minutes at a temperature of 250 °C or more is required finished inactivation. It exists in the climate (for example water, air) occupied by gram-negative microscopic organisms, and bacterial endotoxins (LPS) stay even after the microorganisms pass on.