In the treatment of hospital waste sludge which contains high concentrations of organic components, the amount of hypochlorite has a pseudo-first-order relationship to the formation of organic halides. When waste sludge was treated with 400 ppm of hypochlorite, the amount of TOX found in the chlorinated waste sludge was 291.6 mu g/g, (vs. 68.5 mu g/g of TOX found in original sludge). The distributions of TOX were 11.2 (3.8%), 53.0 (18.2%) and 226.9 (78.0%)mu g/g, in the gas, liquid and solid phases, respectively. Ethanol is a common and safe solvent that is used for the extraction of organic halides from sludge. However. the high partitioning coefficient of sludge for microorganism hoc (or chlorinated microorganism hoc) retards the extraction effectiveness of ethanol. The lack of variation in the 1R absorption spectra of the residues at various molecular weights suggests that there is only a slight change in the functional groups during chlorination. (C) 1998 Elsevier Science Ltd. AII rights reserved.