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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Parent compound and hydrolysis product isovaleric acid: Adsorption to solid soil phase is not expected.

Key value for chemical safety assessment

Additional information

Parent compound isovaleryl chloride:

The adsorption potential of isovaleryl chloride (CAS 108 -12 -3) was calculated using EPI Suite v.4.10. The estimates for the uncharged molecule using the MCI and the Kow method of the KOCWIN v2.00 module from SRC EPI Suite v4.10 are listed below.

Isovaleryl chloride (CAS 108 -12 -3) rapidly decomposes in water and forms HCl (CAS 7647 -01 -0) and isovaleric acid (CAS 503 -74 -2).
Therefore, the model calculation may be of low relevance.

Uncharged molecule:

- MCI method: Koc = 4.214; log Koc = 0.6247

- Kow method: Koc = 16.23; log Koc = 1.2102

Based on the MCI method of the uncharged molecule, adsorption to solid soil phase is not expected.

Hydrolysis compound isovaleric acid:

The adsorption potential was estimated for isovaleric acid (503 -74 -2) using the MCI and the Kow methods of the KOCWIN v2.00 module from SRC EPI Suite v4.10. These estimates are representative for uncharged molecules. The substance ionises in aqueous solutions, therefore the adsorption coefficient was calculated according to Franco & Trapp (2008) to correct for the charged molecule at pH 4, 5, 7 and 9. The Koc values are listed below.

 

Uncharged molecule:

- MCI method: Koc = 4.022; log Koc = 0.6045

- Kow method: Koc = 6.271; log Koc = 0.7974

Charged molecule:

- Franco & Trapp, 2008:

pH 4: Koc = 81; log Koc = 1.91

pH 5: Koc = 81; log Koc = 1.91

pH 7: Koc = 51; log Koc = 1.71

pH 9: Koc = 51; log Koc = 1.70

Based on the corrections for the charged molecule according to Franco & Trapp (2008), adsorption to the solid soil phase is not expected.