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Environmental fate & pathways

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Substance is a hydrocarbon UVCB. Standard tests on stability are intended for single substances and are not appropriate for this complex substance.

However, phototransformation in air is characterized using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance with the PETRORISK model (see Product Library in PETRORISK spreadsheet attached to IUCLID Section 13).

Hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane and other constituent chemicals of the C7-C9 aliphatic hydrocarbon solvents category are composed of carbon and hydrogen and are not amenable to hydrolysis because of their molecular structure and the chemical reaction required for this type of transformation to occur. Hydrolysis of an organic molecule occurs when a molecule (R-X) reacts with water (H2O) to form a new carbon-oxygen bond after the carbon-X bond is cleaved. Mechanistically, this reaction is referred to as a nucleophilic substitution reaction, where X is the leaving group being replaced by the incoming nucleophilic oxygen from the water molecule. The leaving group, X, must be a molecule other than carbon because for hydrolysis to occur, the R-X bond cannot be a carbon-carbon bond. The carbon atom lacks sufficient electronegativity to be a good leaving group and carbon-carbon bonds are too stable (high bond energy) to be cleaved by nucleophilic substitution. Thus, hydrocarbons are not subject to hydrolysis and this fate process will not contribute to the degradative loss of chemical components in this category from the environment. Consequently, no study on hydrolysis needs to be conducted.