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Environmental fate & pathways

Phototransformation in soil

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Description of key information

Di-isodecyl phthalate ester (DIDP; CAS #68515-49-1) does not absorb light within a range of 290 to 750 nm. Therefore, direct photolysis will not contribute to the degradation of DIDP in the terrestrial environment because it does not absorb light at wavelengths >290 nm, i.e., in the range that contributes to this process.

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Additional information

Direct photochemical degradation in soil occurs through the absorbance of solar radiation by a chemical substance. If the absorbed energy is high enough, then, in the resultant excited state, the chemical may undergo a transformation. A prerequisite for direct photodegradation is the ability of one or more bonds within a molecule to absorb ultraviolet (UV)/visible light in the 290 to 750 nm range. Light wavelengths longer than 750 nm do not contain sufficient energy to break chemical bonds, and wavelengths below 290 nm are shielded from the earth by the stratospheric ozone layer. An approach to assessing the potential for di-isodecyl phthalate ester (DIDP; CAS #68515-49-1) to undergo direct photochemical degradation is to assume that degradation will occur in proportion to the amount of light wavelengths >290 nm absorbed by DIDP molecules. DIDP does not absorb light within a range of 290 to 750 nm. Therefore, direct photolysis will not contribute to the degradation of DIDP in the terrestrial environment because it does not absorb light at wavelengths >290 nm, i.e., in the range that contributes to this process.