Handling genotoxic compounds commonly used in
cancer chemotherapy generates contaminated wastes that require decontamination before disposal. Chemical methods are an alternative and/or a
complement to incineration for the treatment of wastes and spills. As part of a program initiated by the International Agency for Research on
Cancer (IARC), three chemical methods readily available in the hospital environment, viz
sodium hypochlorite (NaOCl, 5.25%),
hydrogen peroxide (H2O2, < or = 30%) and
Fenton reagent (FeCl2, 2H2O; 0.3 g in 10 ml H2O2, 30%), were tested for the degradation of three
alkylating agents (
cyclophosphamide, CP;
ifosfamide, IF, and
melphalan). Pharmaceutical preparations 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 chromatography. The mutagenicity of the degradation residues was tested by means of the Ames test using tester strains of Salmonella typhimurium TA 97a, TA 98, TA 100 and TA 102 with and without an exogenous metabolic activation system. Complete disappearance of CP was observed after 1 h with all degradation methods. However, direct
mutagens were generated 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 Fenton technique, and after 3 h with the NaOCl method. Direct-acting
mutagens 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 the treatments. The use of NaOCl (5.25%) proved the most efficient system for degradation of the three
alkylating agents.