Mutation Research 680 (2009) 31–42 Contents lists available at ScienceDirect Mutation Research/Genetic Toxicology and Environmental Mutagenesis journal homepage: www.elsevier.com/locate/gentox Community address: www.elsevier.com/locate/mutres Reduction of use of animals in regulatory genotoxicity testing: Identification and implementation opportunities—Report from an ECVAM workshop  Stefan Pfuhler a,q,∗ , David Kirkland b , Peter Kasper c,q , Makoto Hayashi d , Philippe Vanparys e,q , Paul Carmichael f,q , Stephen Dertinger g , David Eastmond h , Azeddine Elhajouji i , Cyrille Krul j , Andreas Rothfuss k , Gabriele Schoening l , Andrew Smith m , Guenter Speit n , Claire Thomas o,q , Jan van Benthem p,q , Raffaella Corvi o,q a Procter & Gamble, Cosmital SA, Rte de Chesalles 21, CH-1723 Marly, Switzerland b Covance Laboratories Ltd., Otley Road, Harrogate HG3 1PY, England, United Kingdom c Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, D-53175 Bonn, Germany d Biosafety Research Center, Foods, Drugs and Pesticides, 582-2, Shioshinden, Iwata, Shizuoka 437-1213, Japan e Altoxicon BVBA, Boskant 101, B-2350 Vosselaar, Belgium f Unilever Colworth Science Park, Safety and Environmental Assurance Centre, Sharnbrook, Bedfordshire MK44 1LQ, England, United Kingdom g Litron Laboratories, 200 Canal View Blvd., Rochester, NY 14623, USA h Environmental Toxicology Graduate Program, 2109 Biological Sciences Building, University of California, Riverside, Riverside, CA 92521, USA i Novartis Pharma AG, MUT-2881.5.38, CH-4002 Basel, Switzerland j TNO Quality of Life, Utrechtseweg 48, PO Box 360, 3500 AJ Zeist, The Netherlands k Bayer Schering Pharma AG, Nonclinical Drug Safety, 13342 Berlin, Germany l European Chemicals Agency – ECHA, Directorate B.2, P.O. Box 400, FI-00121 Helsinki, Finland m Health and Safety Executive (HSE), Redgrave Court, Merton Road, Bootle, Merseyside L20 7HS, England, United Kingdom n Ulm University, Human Genetics, Oberer Eselsberg, Ulm D-89069, Germany o In vitro Methods/European Centre for the Validation of Alternative Methods (ECVAM), Institute for Health and Consumer Protection (IHCP), JRC of the European Commission TP, 580, Via E. Fermi 2749, 21027 Ispra (Va), Italy p National Institute for Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, P.O. Box 1, 3720 BA Bilthoven, The Netherlands q European Centre for the Validation of Alternative Methods (ECVAM) – Genotoxicity and Carcinogenicity Expert Team, Italy article info Article history: Received 30 March 2009 Received in revised form 28 July 2009 Accepted 27 August 2009 Available online 16 September 2009 abstract In vivo genetic toxicology tests measure direct DNA damage or the formation of gene or chromosomal mutations, and are used to predict the mutagenic and carcinogenic potential of compounds for regula- tory purposes and/or to follow-up positive results from in vitro testing. These tests are widely used and consume large numbers of animals, with a foreseeable marked increase as a result of the EU chemicals legislation (REACH), which may require follow-up of any positive outcome in the in vitro standard battery with appropriate in vivo tests, regardless of the tonnage level of the chemical. A 2-day workshop with genotoxicity experts from academia, regulatory agencies and industry was hosted by the European Centre for the Validation of Alternative Methods (ECVAM) in Ranco, Italy from 24 to 25 June 2008. The objectives of the workshop were to discuss how to reduce the number of animals in standard genotoxicity tests, whether the application of smarter test strategies can lead to lower animal numbers, and how the possibilities for reduction can be promoted and implemented. The workshop agreed that there are many reduction options available that are scientifically credible and therefore ready for use. Most of these are compliant with regulatory guidelines, i.e. the use of one sex only, one administration and two sampling times versus two or three administrations and one sampling time for micronucleus (MN), chromosomal aberration (CA) and Comet assays; and the integration of the MN endpoint into repeat-dose toxicity studies. The omission of a concurrent positive control in routine CA and MN tests has been proven to be scientifically acceptable, although the OECD guidelines still require this; also the combination of acute MN and Comet assay studies are compliant with guidelines, except for sampling times.  This document represents the consensus view of the participants as individual scientists and does not necessarily represent the policies and procedures of their respective institutions. ∗ Corresponding author. Tel.: +41 26 435 2520. E-mail address: pfuhler.s@pg.com (S. Pfuhler). 1383-5718/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.mrgentox.2009.09.002