Photocatalytic processes in the presence of titanium dioxide provide an interesting route to destroy hazardous organic contaminants, being operational in the UV-A domain with a potential use of solar radiation. Numerous photocatalytic reactions have been tested showing that organic contaminants in water can be completely mineralized (i.e, converted into CO2, H2O, NO3-, SO42-, etc.) by irradiation in the presence of TiO2. In this paper, the photocatalytic degradation of a monoalkyl dithiocarbamate (Vapam((R))) by TiO2 illuminated suspensions has been investigated at bench scale. The determination of the effects of various kinetic factors on the photocatalytic: degradation and the determination of the nature of the principal intermediates form part of the focus of this study. This research also involves the characterisation of the titanium dioxide surface by X-ray photoelectron spectroscopy to obtain information about the composition and chemical state of the catalyst surface. Preliminary field tests have shown that this pesticide can not be completely mineralized when treating diluted industrial wastes from manufacturing industries. The experimental results presented suggest that inactivation of titanium dioxide by sulphur occurs. These results have significant implications to commercialise solar photocatalytic detoxification technology since the catalyst cost has a major impact on the wastewater cost,