The author would like to thank the editors for their kind invitation to participate in this special edition of the journal and to state that comments and views expressed in this article are solely those of the author. Regulation EC 1907/2006 [1] introduces several major activities associated with the movement of chemicals, including harmonisedmeasures to ensure the protection of human health and the environment and to promote the development of alternative methods for the assessment of hazards associated with chemical substances. Management of chemicals should be based upon a complete evaluation of the associated risk and the application of proportionate risk management strategies. In order to monitor protection of the environment and of human health, it is necessary to assess exposure of relevant populations. Exposure assessment requires the ability to measure substances of possible concern with adequate confidence – unambiguously and with an uncertainty that is low enough not to bias any related risk assessment. Risk is the product of two factors – the hazard associated with a substance and the exposure to the substance.