The European Food Safety Authority (EFSA) has launched a public consultation on the draft guidance developed by its Scientific Committee for carrying out 90-day feeding studies on whole food and feed in rodents. The draft guidance proposes a test design – randomised block design – which aims to maximise the power of the experiment while limiting the number of test animals used. All stakeholders and interested parties are invited to provide their comments through an online public consultation by 22 August 2011.
90-day animal feeding studies are often used to provide information for the risk assessment of food and feed and/or of individual substances contained therein. Until now, applicants wishing to perform a 90-day feeding trial of whole food or feed have been advised to adapt the OECD testing guidelines designed for testing single substances.
EFSA has developed draft guidance to support those submitting applications for risk assessment. The advice covers how to design, conduct, analyse, report and interpret 90-day oral toxicity studies of whole food and feed in rodents. This guidance will support applicants in carrying out feeding trials which may be used for the risk assessment of novel foods as well as food and feed derived from genetically modified organisms. The guidance, prepared at the request of the European Commission, is part of the Scientific Committee’s ongoing efforts to contribute to the advancement of risk assessment methodologies.
EFSA recommends the use of a so-called randomised block design. This design involves dividing the experiment into blocks (“mini-experiments”) of two animals per cage, which are matched for age and weight. Such a design increases the power of the experiment by reducing possible sources of variation between the tested animals while limiting the number of animals used. Housing rodents as pairs is also recommended from a welfare perspective, as this is known to reduce stress in the animals.
The guidance provides practical examples of how to apply randomised block design for animal studies carried out to assess the safety of novel foods and GMOs. The Scientific Committee recommends the use of 96 animals for such studies while recognising that the appropriate number of animals depends on the methodology used. Applicants should always investigate and scientifically justify their testing strategy regardless of their chosen methodology.
The guidance also includes direction for the formulation of test diets, statistical analysis and for further harmonised reporting of the results.
In finalising its opinion, the Scientific Committee will consider all comments received during the public consultation as appropriate. A summary report will be published on the EFSA website along with the final guidance expected to be completed by autumn 2011.
EFSA’s Scientific Committee supports the work of EFSA’s Scientific Panels on scientific matters of a horizontal nature and is responsible for general co-ordination to ensure consistency in the scientific opinions prepared by the Scientific Panels. The Scientific Committee focuses on developing harmonised risk assessment methodologies in fields where EU-wide approaches are not already defined.
 OECD Guideline for the Testing of Chemicals – Repeated Dose 90-day Oral Toxicity Study in Rodents (OECD TG 408)