The Way Forward

Regulatory programs such as the EU Registration, Evaluation, and Authorisation of Chemicals (REACH), and various EPA voluntary testing programs will continue to substantially increase animal use for toxicity testing endpoints such as organ toxicity testing, which have no validated alternative test methods. The "level of research and development" has been identified as the major rate limiting step in generating non-animal alternatives for chronic toxicity testing (ECVAM, 2002). Several ECVAM working groups have reviewed existing methods and/or provided detailed short and long-term recommendations for moving forward the research and development needed to obtain replacement methods for long-term toxicity testing (ECVAM, 2002; Pfaller, et al., 2001; Prieto, et al., 2005; Prieto, et al., 2006). The report by Prieto, et al. (2006) recognized that the timeframe required for developing and validating new methods now extends beyond the time requirements for these urgently needed alternative methods.

The 2005 ECVAM working group proposed the following timeframe for the validation of partial replacement methods for liver, kidney, inhalation, and neurotoxicity for 28-day and 90-day repeat dose testing (Prieto, et al., 2005):

For more on The Way Forward, read the following invited commentaries on repeated dose/organ toxicity testing:

• In Vitro Evaluation of Human Xenobiotic Toxicity: Scientific Concepts and the Novel Integrated Discrete Multiple Cell Co-culture (IdMOC) Technology by Albert Li
• Alternate Methods for Assessing Respiratory Toxicity Using Non-animal Methods by Mark Riley