Diphenyl carbonate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Principles of method if other than guideline:

Calculation using PCKOC (v. 1.66) of EPI-Suite (v. 3.20) as well as according to Sabljic (1995, QSAR modelling of soil sorption. Improvements and systematics of logKoc vs. logKow correlations. Chemosphere, Vol. 31, 4498-4514) and Gerstl (1990, Estimation of organic chemical sorption by soils, Journal of Contaminant Hydrology, 6, 357-375).

GLP compliance:

no

Type of method:

other: Estimation

Media:

soil

Radiolabelling:

no

Type:

Koc

Value:

439 - 3 926 dimensionless

Estimation method	Koc	Input parameter	Reference
log Koc = 0.679 log Kow + 0.663	740	Log Kow = 3.25	Gerstl, 1990
log Koc = 0.49 log Kow + 1.05	439	log Kow = 3.25	Sablijc, 1995
Molecular connectivity method	3926		Currenta, 2008b (EPI Suite used for calculation)

A mean measured logKow-value of 3.25 of diphenyl carbonate was used for calculation.

Conclusions:

The estimated Koc values for diphenyl carbonate, using different accepted calculation methods are 439, 740 and 3926.

Executive summary:

In order to predict the mobility and fate of diphenyl carbonate in soil and sediments, the organic carbon-water partition coefficient (Koc) was calculated using different estimation methods following the recommendations of the Guidance document on information requirements and chemical safety assessment, chapter R.7a: Endpoint specific guidance document R.7a (ECHA, 2014).

The values were calculated using PCKOC (v. 1.66) of EPI-Suite (v. 3.20) as well as according to Sabljic (1995, QSAR modelling of soil sorption, Improvements and systematics of logKoc vs. logKow correlations, Chemosphere, Vol. 31, 4498-4514) and Gerstl (1990, Estimation of organic chemical sorption by soils, Journal of Contaminant Hydrology, 6, 357-375).

The Sablijc and Gerstl methods are based on statistical relationships between Koc and the octanol/water partition coefficient (Kow); the EPI Suite calculations are based upon the molecule’s structure using the molecular connectivity method.

The estimated Koc values for diphenyl carbonate, using different accepted calculation methods are 439, 740 and 3926.

Description of key information

The organic-water partition coefficient (Koc) for diphenyl carbonate was calculated to be 439, 740 and 3926 using three different accepted calculation methods (Currenta, 2008a). This indicates a moderate potential for adsorption.

Key value for chemical safety assessment

Koc at 20 °C:

3 926

Additional information

In the key study, the organic-water partition coefficient (Koc) for diphenyl carbonate was calculated to be 439, 740 and 3926 using three different accepted calculation methods (Currenta, 2008a). This indicates a moderate potential for adsorption. These values have been derived from software calculations; hence this study has been awarded a reliability score of 2 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997).

  

In order to predict the mobility and fate of diphenyl carbonate in soil and sediments, the organic carbon-water partition coefficient (Koc) was calculated using different estimation methods following the recommendations of the Guidance document on information requirements and chemical safety assessment, chapter R.7a: Endpoint specific guidance document R.7a (ECHA, 2014).

The values were calculated using PCKOC (v. 1.66) of EPI-Suite (v. 3.20) as well as according to Sabljic (1995, QSAR modelling of soil sorption, Improvements and systematics of logKoc vs. logKow correlations, Chemosphere, Vol. 31, 4498-4514) and Gerstl (1990, Estimation of organic chemical sorption by soils, Journal of Contaminant Hydrology, 6, 357-375).

The Sablijc and Gerstl methods are based on statistical relationships between Koc and the octanol/water partition coefficient (Kow); the EPI Suite calculations are based upon the molecule’s structure using the molecular connectivity method.

The Koc was determined to be 439 (Sabljic), 740 (Gerstl) and 3926 (EPI-Suite).

According to accepted classification schemes, calculated Koc-values of 100 and 1000 indicate a low to moderate potential of soil sorption. Regarding the wide range of estimation results it is difficult to draw a conclusion of adsorption properties for the substance. The molecular structure and the presence of functional groups of diphenyl carbonate suggest the ability to adsorb onto solids. Therefore, it is considered that the estimated Kow values of 439 and 740 seem to be underestimations. Conversely, the calculated Koc of 3926 is considered to be an overestimation. Furthermore, the calculated value reflects the properties of the undissociated molecule without taking into account the sensitivity of diphenyl carbonate towards hydrolysis.

 

The adsorption of the hydrolysis product phenol was assessed in a European Union Risk Assessment Report (European Chemicals Bureau, 2006). A soil sorption coefficient of 82 was reported and does not provide any indication that a significant adsorption potential is to be expected for phenol.

Further Information

In accordance with Section 9.3.3 of Column 2 of REACH Annex IX, it is considered justified to omit the further information on adsorption/desorption study as the substance and its degradation products are considered to decompose rapidly. Diphenyl carbonate has been shown to rapidly hydrolyse to produce phenol and carbon dioxide. The adsorption and biodegradability of the hydrolysis product phenol were assessed in a European Union Risk Assessment Report (European Chemicals Bureau, 2006) and it was determined that phenol is readily biodegradable and not likely to adsorb.

[LogKoc: 3.59]