PART 1  TECHNICAL SPECIFICATIONS - WHAT DOES EFSA NEED TO  BUY THROUGH THIS PROCUREMENT PROCEDURE?  1.1 BACKGROUND Read-across (RAx) is an approach used in chemical risk assessment that allows for the  screening, classification, prioritization and hazard assessment of chemicals based on the  toxicological data of similar chemicals and is the most common alternative to animal  testing. It provides opportunities for predicting toxicological responses for data-poor  chemicals using data from other substances. However, the similarity within the context of  the predicted endpoint (response) should be justified. As available datasets, data streams  and improved read-across techniques allow greater confidence in this predictive method,  it is becoming increasingly important to ensure its regulatory acceptance. EFSA has recently initiated a project to develop a guidance on the use of RAx to harmonise  its use across different food sectors. In anticipation of this guidance, this procurement  procedure aims at investigating the applicability of RAx for toxicological endpoints for risk  assessment (RA) of chemicals in food/feed. This procurement will focus on and analyse  the repeated-dose toxicity information available to EFSA on pesticide active substances  and their metabolites, since pesticides are the group of compounds under EFSA’s remit  with the largest amount of information. This project would complement a prior related  project which used RAx and similarity analysis for prediction of genotoxicity as carried out  by EFSA pesticide unit 2 . It is anticipated that the outcome of this procurement together  with the insights already gained from the genotoxicity project will provide a robust  scientific basis for the guidance on the use of chemical RAx across EFSA’s remit.  This c all is based on EFSA’s 20 20-2022 draft Work Programme for grants and operational  procurements as presented in Annex IX of the Programming Document 2020  – 2022,  available on the EFSA’s website 3 . 1.2 OBJECTIVES  The aim of this procurement procedure is to qualify the applicability domain (in terms of  toxicological endpoints and chemical space) for the use of RAx in food safety. Using pesticides as a model, the overall objective of the contract will be to extract chemical  and toxicological information for active substances and their metabolites/degradation  products (where available) from EFSA’s published  conclusions on pesticides peer review  and related assessment reports, and (i) test the applicability of the RAx approach for  prediction of repeated dose toxicity and (ii) identify supporting biological and toxicological  information for in vivo and in vitro studies that will reduce uncertainty in the RAx. $^{2}$ https://www.efsa.europa.eu/en/supporting/pub/en-1598;  https://efsa.onlinelibrary.wiley.com/doi/abs/10.2903/sp.efsa.2017.EN-1229 3 http://www.efsa.europa.eu/sites/default/files/corporate_publications/files/amp2022.pdf 4 