Physico-chemical property prediction of emerging pollutants: PFC and (B)TAZ for environmental distribution,

Perfluorinated compounds (PFCs) are a family of chemicals with a long carbon chain which is predominantly substituted by fluorine. They are used in different materials as non-adhesives, waterproof fabrics, fire-fighting foams, etc. (Benzo)triazoles (B/TAZs) are another class of chemicals with multi-nitrogenated aromatic ring system. They are widely used in industrial processes, deicing agents (1H-BTAZs), pharmaceuticals and pesticides. These chemicals are considered as “emerging pollutants” as they are broadly distributed in the environment because of their extensive use and are considered to be hazardous as they cause adverse effects to humans and other non-target species. Their high concern as pollutants, lack of data and crucial Authorisation under REACH legislation urges for a need to maximize the information inherited in the existing data. Internally robust and externally validated QSPR models were developed for the endpoints, as also recommended under the REACH regulation, to predict large set of unknown properties for existing or not yet synthesized chemicals. For PFCs, three QSPR models each on Water Solubility (WS), Vapor pressure (VP) and Critical Micelle Concentration (CMC) were developed and structural applicability domain (AD) study was verified. 174 (78.7%) compounds were found within the AD of all three models. The multivariate analysis by Principal Component Analysis (PCA) was performed for the prediction of these chemicals. In addition, Bioconcentration Factors (BCF) values were collected for most common PFCs and the relationship between the end-points was studied. The increasing trend of BCFs is in opposite direction to that of WS and CMC and the trend is found different for carboxylates and sulfonates. For B/TAZs, four QSPR models each on WS, VP, KOW (Octanol/Water partition) and Melting Point (MP) were developed. 351 compounds were studied for structural AD study and out of which 66 are found within the AD of all four models for which at least one experimental data was available. These compounds were studied using PCA in a multivariate plot to understand their leaching and volatility behavior. Comparison with soil sorption partition coefficient (KOC) was performed by using predictions from earlier published models. More soluble, more volatile and more sorbed chemicals are highlighted. The 1H-B/TAZs were found to be among the more soluble and less sorbed compounds.