In this H2020 SAbyNA deliverable, we discuss suggested improvements in existing release, fate and exposure 
models, with a particular focus on improvements that could be made to GUIDEnano modules. This deliverable 
acts as an extension of the interim Deliverable 2.8 (10.5281/zenodo.10822215) and documents work carried out in Task 2.2 (Optimization and usability improvement of data, methods and tools to estimate release, fate and exposure). The conclusions 
from this deliverable are being fed into WP6 to contribute to the creation of the SAbyNA Guidance Platform.

We report on our detailed assessment of environmental release, fate and exposure models, focussing on 
aspects such as processes and algorithms, input parameters, sensitivity/uncertainty analyses and 
scenarios/case studies. We identify several potential improvements to GUIDEnano, such as the inclusion of 
default parameter sets (e.g. for water composition, material phys-chem parameters and lifecycle scenarios), 
updated process algorithms and the inclusion of Specific Environmental Release Categories (SPERCs) to 
provide estimates of environmental release.

We discuss improvements required in the human exposure models and how these could be incorporated into 
GUIDEnano modules. The suggested improvements to GUIDEnano include providing default parameter sets, 
inclusion or improvement of specific processes (such as relative humidity and VOCs), read-across for exposure 
scenarios, whether a warning for exposure can be included and incorporating uncertainty assessment.
These suggestions are now being discussed for implementation with the GUIDEnano developers and WP6.