"Endotoxins are toxins found within the outer membranes of certain bacteria (called Gramnegative bacteria). The bacteria does not have to be alive for endotoxins to be toxic to humans.  Exposure can occur through inhalation, intestinal
tract absorption, or skin cuts. Endotoxins are linked to water systems (especially ones
containing sewage or recycled water).  Endotoxins have also been found in buildings with
humidifiers and those with sewage leaks. Health effects vary widely depending on the individual,
dosage, and type of exposure. However, once in the bloodstream at high enough levels, endotoxins may cause fever, shock or even
death. Sampling for the presence of suspected endotoxins should be done by professionals with specialized equipment and training."  Gordon & Rees LLP