Cyclohexylidenebis[tert-butyl] peroxide

Henry's Law constant

Link to relevant study record(s)

Reference

Endpoint:

Henry's law constant

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2022-07-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Qualifier:

no guideline required

Principles of method if other than guideline:

HenryWin (v3.20): HENRYWIN estimates the Henry's Law Constant of organic compounds at 25 °C using the methodology originally described by Hine and Mookerjee (1975).

GLP compliance:

no

Specific details on test material used for the study:

CC(C)(C)OOC1(OOC(C)(C)C)CCCCC1

Key result

H:

60 500 Pa m³/mol

Temp.:

25 °C

Remarks on result:

other: calculation based on experimental water solubility and vapour pressure

H:

65.3 Pa m³/mol

Temp.:

25 °C

Remarks on result:

other: QSAR estimate based on the chemical structure

Conclusions:

The Henry Laws Constant of the test item was estimated with EpiSuite. Based on the structural elements a value of 65.3 Pa.m³/mol was calculated. Based on the experimental phys-chem properties of the test item - water solubility (2.1 mg/L) and vapour pressure (488 Pa at 25 °C), a value of 60500 Pa.m³/mol was calculated. The estimated Henry's Law Constant with QSAR is outside of the applicability domain and is considered as less reliable compared to the constant calculated based on the experimental values.

In conclusion, the Henry Laws Constant calculated from the experimentally obtained phys-chem properties, clearly shows that the test item is highly volatile.

Executive summary:

The log Koc was calculated using HENRYWIN v3.20 as part of EPISuite v4.11 from US Environmental Protection Agency.

Using HENRYWIN v3.20 the Henry's Law Constant of the test item was calculated to be 65.3 Pa-m³/mol at 25 °C (EPI Suite, 2014).

 

The adequacy of a prediction depends on the following conditions:

a) the (Q)SAR model is scientifically valid: the scientific validity is established according to the OECD principles for (Q)SAR validation;

b) the (Q)SAR model is applicable to the query chemical: a (Q)SAR is applicable if the query chemical falls within the defined applicability domain of the model;

c) the (Q)SAR result is reliable: a valid (Q)SAR that is applied to a chemical falling within its applicability domain provides a reliable result;

d) the (Q)SAR model is relevant for the regulatory purpose.

 

For assessment and justification of these 4 requirements the QMRF and QPRF files were developed and attached to this study record.

 

Description of the prediction Model

The prediction model was descripted using the harmonised template for summarising and reporting key information on (Q)SAR models. For more details please refer to the attached QSAR Model Reporting Format (QMRF) file. 

 

Assessment of estimation domain

The assessment of the estimation domain was documented in the QSAR Prediction Reporting Format file (QPRF). Please refer to the attached document for the details of the prediction and the assessment of the estimation domain.

 

Description of key information

The Henry Laws Constant of the test item was estimated with EpiSuite. Based on the structural elements a value of 65.3 Pa.m³/mol was calculated. Based on the experimental phys-chem properties of the test item - water solubility (2.1 mg/L) and vapour pressure (488 Pa at 25 °C), a value of 60500 Pa.m³/mol was calculated. 

In conclusion, the Henry Laws Constant calculated from the experimentally obtained phys-chem properties, clearly shows that the test item is highly volatile.

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):

60 500

at the temperature of:

25 °C