Describing the impact of trace organics in sludge on soil-plant systems can be an even greater challenge than is faced with trace elements. One reason is the sheer number of compounds potentially involved. Literally thousands of trace organics exist and many, if not all, can be expected in sewage sludge at highly variable concentrations. At the same time, the literature discussing the effects of trace organics on soil-plant systems is much less volumious than the trace element literature. Undoubtedly, the paucity of scientific studies on trace organics is due to the complexity of studying these chemicals and the expense of trace organic analyses. To facilitate discussion, the large number of organic chemicals were divided into groups which tend to have similar chemical and physical properties. Various organics could then be discussed by groups relevant to their prevalence in sludge, fates in the soil-plant system, and recent efforts at assessing the risk of trace organic additions to the soil via sludge application.