The FDA has established allowable clinical levels of endotoxin.  However, in mice chronic exposure to subclinical levels of endotoxin results in increased mortality, most likely due to cardiac fibrosis since cardiac cells express Toll-4 receptors.  This increase in mortality occurs with minimal effects that do not persist after exposure and highlights the need for accurate and sensitive endotoxin detection in all therapeutics.  This work, by the cardiology group from the UC San Diego School of Medicine, was recently published in PLOS One:

Recurrent Exposure to Subclinical Lipopolysaccharide Increases Mortality and Induces Cardiac Fibrosis in Mice

Scientists at BioDtech, Inc. have measured previously undetectable levels of endotoxin which could cause activation of the immune system.  BioDtech products are designed to more accurately detect endotoxin and remove it from proteins and DNA.

BioDtech, Inc. offers many products to assist in both removal and detection of endotoxin. 

EndoBind-R™ is an affinity chromatography media designed to remove endotoxin from aqueous solutions.  The ligand is highly specific for endotoxin resulting in high detoxification and low product loss.

EndoPrep™ is a sample preparation kit used in conjunction with LAL or rFC assays.  It removes the interfering effects of proteins that can mask endotoxin or inhibit enzymatic assays thus providing more accurate  endotoxin quantitation.