CHEMICAL DEGRADATION OF WASTES OF ANTINEOPLASTIC AGENTS - CYCLOPHOSPHAMIDE, IFOSFAMIDE AND MELPHALAN

Handling genotoxic compounds commonly used in cancer chemotherapy gene rates contaminated wastes that require decontamination before disposal . Chemical methods are an alternative and/or a complement to incinerat ion for the treatment of wastes and spills. As part of a program initi ated by the International Agency for Research on Cancer (IARC), three chemical methods readily available in the hospital environment, viz so dium hypochlorite (NaOCl, 5.25%), hydrogen peroxide (H2O2, less than o r equal to 30%) and Fenton reagent (FeCl2, 2H(2)O; 0.3 g in 10 ml H2O2 , 30%), were tested for the degradation of three alkylating agents (cy clophosphamide, CP; ifosfamide, IF, and melphalan). Pharmaceutical pre parations corresponding to the most highly concentrated administration solutions in either NaCl (0.9%) or dextrose (5%) were inactivated by oxidation volume/volume with each of the methods for at least 1 h. The efficiency of degradation was monitored by high-pressure liquid chrom atography. The mutagenicity of the degradation residues was tested by means of the Ames test using tester strains of Salmolnella typhimurium TA 97a, TA 98, TA 100 and TA 102 with and without an exogenous metabo lic activation system. Complete disappearance of CP was observed after 1 h with all degradation methods. However, direct mutagens were gener ated by the Fenton oxidation technique in the presence of dextrose (5% ). IF was completely degraded by the Fenton reagent and NaOCl methods. No mutagenic residues were detected after 1 h of treatment with the F enton technique, and after 3 h with the NaOCl method. Direct-acting mu tagens remained after the H2O2 treatment in the presence of dextrose ( 5%). Complete degradation of melphalan was achieved in 1 h by each of the three methods, and no mutagenic residues were produced by any of t he treatments. The use of NaOCl (5.25%) proved the most efficient syst em for degradation of the three alkylating agents.