Chemical contamination of the human food chain may arise in several ways. Direct contamination can occur by contact with the food – for example, hygienic cleaning residues can transfer to food from a treated surface if it is not properly rinsed. Indirect transfer can occur from materials used in food manufacture to a finished food product, including transfer between the animal feed and human food chains. However, human dietary exposure to chemicals that pass up the food chain by transfer from the environment is possibly the greatest concern. This pathway into the food chain is typical of the more persistent and potentially bio-accumulative compounds, such as dioxins, PCBs, chlorinated paraffins, brominated diphenyl ethers and perfluorinated compounds. Many chemicals that are released into the environment may have the potential to transfer into food or drinking water. It should be noted that REACH addresses chemicals that are manufactured. Unintentionally produced pollutants such as PAHs and PCDD/Fs are outside the scope of REACH and are addressed by implementation of the main requirements of the UNECE POPs protocol.