An Alternative Safety Profiling Algorithm (ASPA) to transform next generation risk assessment into a structured and transparent process
Leist, Marcel Tangianu, Silvia Affourtit, Femke Braakhuis, Hedwig Colbourne, John Cöllen, Eike Dreser, Nadine Escher, Sylvia E Gardner, Iain Hahn, Stefan
Leist, Marcel
Tangianu, Silvia
Affourtit, Femke
Braakhuis, Hedwig
Colbourne, John
Cöllen, Eike
Dreser, Nadine
Escher, Sylvia E
Gardner, Iain
Hahn, Stefan
Series / Report no.
Open Access
Type
Journal Article
Article
Article
Language
en
Date of publication
2025-10-16
Year of publication
Research Projects
Organizational Units
Journal Issue
Title
An Alternative Safety Profiling Algorithm (ASPA) to transform next generation risk assessment into a structured and transparent process
Translated Title
Published in
ALTEX 2026; 43(1):158-175
Abstract
Next generation risk assessment (NGRA) strategies use animal-free new approach methodologies (NAMs) to generate information concerning chemical hazard, toxicokinetics (ADME), and exposure. The information from these major pillars of data gathering is used to inform risk assessment and classification decisions. While the required types of data are widely agreed upon, the processes for data collection, integration and reporting, as well as several decisions on the depth and granularity of required data, are poorly standardized. Here, we present the Alternative Safety Profiling Algorithm (ASPA), a broad-purpose, transparent, and reproducible risk assessment workflow that allows documentation and integration of all types of information required for NGRA. ASPA aims to make safety assessments fully traceable for the recipient (e.g., a regulator), delineating which steps and decisions have led to the final outcome and why certain decisions were made. An overarching objective of ASPA is to ensure that identical data input yields identical outcomes in the hands of independent assessors. Therefore, ASPA is not just a data gathering workflow; it also considers data interdependencies and requires precise justification of intermediate decisions. This includes the monitoring and assessment of uncertainties. To assist users, the ASPA-assist software was developed. It formalizes the reporting process in a reproducible and standardized fashion. By guiding an operator step-by-step through the ASPA workflow, a complete and comprehensive report is assembled, whereby all data, methods, operator activities, and intermediate decisions are recorded. Practical examples illustrating the broader applicability of ASPA across various regulations and problem formulations are provided through case studies.
Researchers and safety experts have developed animal-free test methods to assess chemicals. These include in vitro tests, computer models, and simulations of how a chemical behaves in the body. While the required information is clear, the way it is collected, combined and reported is not standardized. The Alternative Safety Profiling Algorithm (ASPA) provides a transparent, reliable and standardized workflow for chemical safety assessment based on non-animal methods. It records all steps and decisions, tracking uncertainties, showing how conclusions are reached and why certain decisions were made. The ASPA-assist software guides users step-by-step and assembles comprehensive reports. ASPA and ASPA-assist are presented and explained here. Case studies are used to show how ASPA can be applied across chemicals and regulations.