Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Adsorption/desorption

The determination was carried out using a HPLC screening method, designed to be compatible with Method C19 Adsorption Coefficient of CommissionRegulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

The method guideline states that the measurement of adsorption coefficient should be carried out on substances in their ionised and unionised forms. However, the dissociation constants of certain functional groups found in the test item made it impossible to satisfy this criteria. 

From structural information supplied by the Sponsor, estimations of the phenol functional group dissociation constants of 10.3 to 11.8 were generated using predictive computer modelling (SPARC version 4.6,October 2011, w4.6.1691-s4.6.1687).

Therefore, formation of the ionised form of the test item would only occur under basic conditions (pH >8). As such pH’s are not environmentally relevant, only a single determination was performed at an approximately neutral pH.

The adsorption coefficient (Koc) of the test item has been determined to be within the range 91.8 to 5.79 x 103, log10Koc 1.96 to 3.76. The dominant component of the test item (90.0% by percentage area normalisation) resulted in an adsorption coefficient value of 2.43 x 103, log10Koc 3.39.

Henry's Law Constant

Henry's law constant was calculated to be 1.277E-06 Pa.m3/mol at 25 °C based on experimental water solubility vapour pressures . This value indicates a low rate of volatilisation from surface water is expected.