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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Adsorption to the solid soil phase is not expected.

Key value for chemical safety assessment

Koc at 20 °C:
3.2

Additional information

QSAR-disclaimer

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met.

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of Propanoic acid, 2,2-dimethyl- (CAS 75-98-9) (Q)SAR results were used for the estimation of the adsorption potential. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

Therefore, further experimental studies on the adsorption potential are not provided.

 

Assessment

In order to assess the adsorption potential of the substance, the Koc value was estimated using QSAR models. According to the MCI method of the KOCWIN v2.00 module of EPI Suite v4.11 the substance has a Koc of 3.2 L/kg (log Koc = 0.51). The estimation of the MCI module was selected as key value as it is more reliable than the log Kow method of KOCWIN v2.00, which estimates the KOC based on the n-octanol/water partition coefficient (measured log Kow = 1.8; Hexion, 1983). The latter method resulted in a Koc of 14.17 L/kg (log Koc = 1.15); the substance is within the applicability domain of both estimation models. The estimated Koc values represent a best-fit to the majority of experimental values. However, the Koc may be sensitive to pH.

 

Based on the estimated data, adsorption to the solid soil phase is not to be expected.

[LogKoc: 0.505]