attempt to detoxify. This policy can result in substantial financial losses to farmers and other parties on whose property these contaminants are detected. If regulated levels are exceeded in one sample, the impacts are rarely limited to one area, or within the sampling period. It is therefore important to establish the extent of the contamination, distinguish the potential source(s) and identify the duration of the contamination event. These determinations are especially challenging to account for background noise or when multiple sources of these contaminants are present within a 10 kilometre (km) radius of the investigated area and could have contributed to the contamination. This manuscript examine potential pitfalls in the analysis of (PCBs), dioxins (PCDDs) and furans (PCDFs) in terms of their regulated levels, sampling challenges, the analysis of samples and statistical interpretation of the test data. 2 REGULATED LEVELS PCDD/F and PCBs are detected in the environment as complex mixtures. To assess the risks to human health and the environment, internationally agreed Toxic Equivalency Factors (TEFs) have been developed and are regularly updated by the World Health Organisation (WHO). The current TEFs are based on the findings of Van den Berg et al.