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Environmental fate & pathways

Phototransformation in air

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Description of key information

The predicted second-order rate constant for reaction of OH radical with tin bis(2-ethylhexanoate) is 9.9 x 10 -12 cm3/molecule*sec.  This rate constant equates to an estimated half-life of 38.9 hrs, or 1.6 days; assuming an OH radical concentration of 500,000 molecules/cm3.  

Key value for chemical safety assessment

Half-life in air:
38.9 h

Additional information

The estimated atmospheric half-life for tin bis (2-ethylhexanoate) is 1.6 days, indicating that the substance will not behave as a persistent atmospheric pollutant if emitted to the air. This half-life is < 2 days, and therefore the substance is not regarded as having potential for long-range transport in the atmosphere.

The training set used to develop the AOPWIN algorithm does not include other Sn(II) organometallic compounds. However, since the mode of reactivity for the tin bis (2-ethylhexanoate) molecule with hydroxyl radical is dominated by reactions with the 2-ethyl hexanoate part (i.e., hydrogen abstraction), the presence of the Sn atom is not expected to result in decreased accuracy of the prediction. The accuracy of this prediction of the second-order rate constant for organic acids was demonstrated by comparing experimental and predicted rate constants for butyric acid. The predicted value deviates from the experimental value by only 12 %.