Endotoxin Reduction in Dust from Heated Cotton Fibers

Cotton was heated in a gas-fired pilot plant dryer at temperatures previously shown to reduce endotoxin levels in fiber. Heating at 255°C for 20 seconds reduced the endotoxin content of dust collected from the fibers by 90% as measured by the Limulus amebocyte lysate assay. However, heat detoxification at 255°C had a detrimental effect on fiber physical properties as evaluated by high volume instrument testing, with a 24% reduction in fiber strength, a 6% reduction in length, and a 7% reduction in uniformity index. Dust release from cotton heated at 255°C was three times that from unheated cotton.