For the evaluation of the environmental impact, reactions between chemical compounds are not considered.
The tool considers only the mix of compounds used for the coatings' formulation. Even though no reactions (and reaction products) are considered the mix of compounds is referred to as "coating" for the sake of continuity.
The SimpleBox4Planet (S4BP) evaluates the environmental fate and distribution of chemicals in the air compartment exclusively in the gas phase, based on physicochemical properties such as vapor pressure and Henry's law constant. The model does not provide particulate-phase outputs. Hence the use of the Lung Exposure Assessment (LungDepo) following S4BP should be approached with caution.
Performance Assessment
In contrast to the environmental fate assessment, the modelling of the contact angles (water WCA, hexadecane HCA, and surface free energy SFE), does not consider the individual type of molecule but the final (reacted) coating where that molecule provides the most functional property.
Lung Exposure Assessment
LungDeposition assessment considers particles which does not apply to volatile compounds.
Volatile compounds are not considered for the LungDepo calculations.
The LungDepo calculates regional lung deposition of particles, which requires the mass concentration of airborne particles as input. Therefore, there is no direct correlation between the outputs of the SimpleBox4Planet and the inputs for the LungDepo simulation. The necessary input for the air concentration has been pre-defined for all the compounds included in the PROPLANET Replication Tool.
Multi-Objective Optimisation
The optimization model is aimed at identifying the optimal coatings to minimize the pollution impact and maximize the production volume. The lung deposition information and performance properties are directly obtained using the respective assessment models.
Toxicity / Safety Assessment
The tool is a simple model intended as a SSbD support tool for use in the early phases of product development. It provides indicative safety information only, which may be associated with high uncertainty, and has no regulatory relevance.
For humans, only the inhalation route is taken into account. Other exposure routes (dermal, oral) are not included.
The tool applies to the general population (e.g. local communities) exposed through the environment. It does not address the safety of workers, users (occupational safety or safety during product use), or vulnerable groups.
The safety reference values (DNELs and PNECs) used for the safety assessment have been retrieved from the ECHA CHEM database, in the respect of the database's Legal notice. ECHA holds no responsibility and/or liability for any use made of the retrieved information.
The safety assessment relies on the availability of safety reference values in the ECHA database. In the presence of data gaps, the reported risk may be underestimated. Data gaps are indicated by dark grey data points in the output graph.
The model does not account for chemical reactions occurring during formulation (e.g. formation of by-products) or within environmental compartments, which may alter the chemical identity and/or physicochemical properties of the substances. This may lead to an under- or overestimation of risk in the safety assessment.
The safety assessment evaluates individual components of the mixture and reports the risk based on the most critical substance (worst-case individual assessment). Mixture effects, such as additive, synergistic, or antagonistic interactions, are not considered, which may increase uncertainty.
General Remarks
This model only covers compounds investigated for PFAS-free coatings in the PROPLANET project.