OBJECTIVETo develop suitable methods for safety destruction of tetramethylene disulfotetramine (TETS) and the medical wastes polluted by TETS.

METHODSThe chemical stability of TETS was evaluated under the conditions of acid, alkali and high temperature. TETS was treated with sodium hydroxide, hydrochloric acid, sulfuric acid and nitric acid under various treatment conditions, i.e. concentration, temperature and time, followed by determining remaining TETS using gas chromatograms to estimating the degradation efficiency of TETS. TETS was put into ampoule and heated under the different conditions of temperature and time. After heat treatment, TETS residue was determined. For evaluating the absorption factor of active carbon to TETS in water and blood, active carbon was added into the water and blood with content of TETS, incubated at room temperature for 24 hours, and then determined the remaining TETS in water and blood.

RESULTSThe complete degradation of TETS was achieved by one of the following treatments: heating with 6.0 mol/L hydrochloric acid at 100 degrees C for half an hour, heating with 3.0 mol/L hydrochloric acid or 6.0 mol/L sodium hydroxide at 100 degrees C for 3 hours, mixing with concentrated sulfuric acid or nitric acid at room temperature for 24 hours, and dry heating at 300 degrees C for 4.5 hours. Active carbon showed a marked effectiveness in absorbing the TETS in blood and water, with the mean absorption efficiency of over 90%.

CONCLUSIONSThe results of this study suggest that TETS powder should be degraded by acid or alkali, and that the solid medical wastes polluted by TETS should be destroyed at high temperature. For the blood and water having contents of TETS, the active carbon should be used as to absorbing the TETS and then be destroyed at high temperature.