Environmental fate and effects of novel quorum sensing inhibitors that can control biofilm formation Adam Lillicrap a, * , Ailbhe Macken a , Aina Charlotte Wennberg a , Merete Grung a , Jan Thomas Rundberget a , Lene Fredriksen a , Anne Aamdal Scheie b , Tore Benneche c , Marc Angl  es d'Auriac a a Norwegian Institute for Water Research (NIVA), Oslo, Norway b Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway c Department of Chemistry, Faculty of Chemistry, University of Oslo, Oslo, Norway highlights graphical abstract  Thiophenones are novel quorum sensing inhibitors that can control biofilm formation.  QSAR predictions significantly under estimated the environmental fate and effects.  Confirmatory ecotoxicity tests are necessary when risk assessing novel compounds. article info Article history: Received 8 April 2016 Received in revised form 5 August 2016 Accepted 17 August 2016 Handling Editor: Tamara S. Galloway Keywords: Thiophenones Fate and effects Quorum sensing inhibitors Biofilms Petroleum industry abstract The formation of bacterial biofilms can have negative impacts on industrial processes and are typically difficult to control. The increase of antibiotic resistance, in combination with the requirement for more environmentally focused approaches, has placed pressure on industry and the scientific community to reassess biofilm control strategies. The discovery of bacterial quorum sensing, as an important mecha- nism in biofilm formation, has led to the development of new substances (such as halogenated thio- phenones) to inhibit the quorum sensing process. However, there are currently limited data regarding the biodegradability or ecotoxicity of these substances. To assess the environmental fate and effects of thiophenones capable of quorum sensing inhibition, candidate substances were first identified that have potentially high biodegradability and low ecotoxicity using quantitative structure activity relationships. Subsequent confirmatory hazard assessment of these substances, using a marine alga and a marine crustacean, indicated that these estimates were significantly under predicted with acute toxicity values more than three orders of magnitude lower than anticipated combined with limited biodegradability. Therefore, although these quorum sensing inhibitors appear a promising approach to control biofilms, they may also have environmental impacts on certain aquatic organisms. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction The control of bacterial biofilm formation (e.g. in industrial processes) is a major challenge and the development of more * Corresponding author. E-mail addresses: ali@niva.no (A. Lillicrap), ama@niva.no (A. Macken), acw@ niva.no (A.C. Wennberg), mgr@niva.no (M. Grung), tru@niva.no (J.T. Rundberget), lfr@niva.no (L. Fredriksen), a.a.scheie@odont.uio.no (A.A. Scheie), tore.benneche@ kjemi.uio.no (T. Benneche), mad@niva.no (M.A. d'Auriac). Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere http://dx.doi.org/10.1016/j.chemosphere.2016.08.083 0045-6535/© 2016 Elsevier Ltd. All rights reserved. Chemosphere 164 (2016) 52e58