Hexadecylamine

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2019-05-03 to 2019-06-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: ISO 4311 - Anionic and non-ionic surface active agents — Determination of the critical micellization concentration

Version / remarks:

1979

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Determination of the critical micellization concentration

Key result

Remarks on result:

not determinable

Remarks:

the test item is unsoluble in water

Preliminary tests on water solubility

In a first preliminary test it was tried to solve the test item in water. For this purpose, four approaches with the following concentrations were created and stirred for five days at 20 °C: 100.4 mg/100 mL, 21.03 mg/100 mL, 9.71 mg/100 mL and 1.09 mg/L. In all four approaches the test item could not be dissolved in water in all four approaches.

 

Another preliminary test was carried out to see if the surface tension changes compared to pure double-distilled water. For this purpose, 101.80 mg of the test item were prepared in 100 mL double-distilled water and stirred for five days at 20 °C. After that 90 mL of this mixture were filtered through an HPLC filter and refilled to 100 mL with double-distilled water. The surface tension of that solution was determined and compared to the surface tension of clear double-distilled water. Here, a clear non-dissolving of the test item was also observed. Compared to double-distilled water no significant differences of the values could be registered.

c [g/L]	σ1[mN/m]	σ2[mN/m]
0.9162	68.47	68.89
double-distilled water	69.33	-a

So the critical micelle concentration of test item at 20 °C according to ISO 4311 could not be determined due to the low solubility of the test item in water. Therefore, it can be concluded that the test item is virtually unsoluble in water.

Conclusions:

The test item is not soluble in water.

Executive summary:

A study was conducted according to ISO 4311 to determine the critical micelle concentration of the test item. The cmc is defined as the concentration of surfactants above which micelles form and, hence, correspond to the upper solubility limit. The cmc is determined by measuring the surface tension at different concentrations of the test item. It was not possible to prepare different concentrations of the test item in water due to the low solubility. A saturated solution of the test substance did not show a difference in surface tension compared to double distilled water. Hence, it was concluded that the test item is insoluble in water.

Reference 2

Endpoint:

water solubility

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Reference 3

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

other information

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

Justification for type of information:

Please refer to the QMRF and QPRF files provided under the section attached justification.

Qualifier:

according to guideline

Guideline:

other: ECHA Guidance on information requirements and chemical safety assessment Chapter R.6: QSARs and grouping of chemicals

Version / remarks:

May 2008

Deviations:

no

Principles of method if other than guideline:

Calculation using WSKOWWIN v1.42 as part of EPISUITE

GLP compliance:

no

Type of method:

other: Calculation

Specific details on test material used for the study:

SMILES : CCCCCCCCCCCCCCCCN

Key result

Water solubility:

0.482 mg/L

Temp.:

25 °C

pH:

7

Remarks on result:

other: The substance is within the applicability domain of the model. The calculation based on the uncharged molecule.

Conclusions:

Using WSKOWWIN v1.42 the water solubility of the test item was calculated to be 0.4823 mg/L at 25 °C. The substance is within the applicability domain of the model.

Executive summary:

The water solubility was calculated using WSKOWWIN v1.42 as part of EPISuite v4.11 from US Environmental Protection Agency.

Using WSKOWWIN v1.42 the water solubility of the test item was calculated to be 0.4823 mg/L 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

Not applicable as the test item is insoluble in water (reference 4.8-1 and 4.8-2).

Additional information

A study was conducted according to ISO 4311 to determine the critical micelle concentration (cmc) of the test item. The cmc is defined as the concentration of surfactants above which micelles form and, hence, correspond to the upper solubility limit. However, the critical micelle concentration of test item at 20 °C could not be determined due to the low solubility of the test item in water (reference 4.8-1). Therefore, it can be concluded that a study is technically not feasible because the test item is insoluble in water. Accordingly, the conduction of another study would not lead to additional value and the study was waived (reference 4.8-2).

As additional information, the water solubility was calculated using WSKOWWIN v1.42 as part of EPISuite v4.11 from US Environmental Protection Agency. Using WSKOWWIN v1.42 the water solubility of the test item was calculated to be 0.4823 mg/L at 25 °C (EPI Suite, 2014). The substance is within the applicability domain of the model. The calculation based on the uncharged molecule (reference 4.8-3).

In conclusion, it was shown in a study according to national standards that the test item is practically insoluble in water. Therefore, further studies on the water solubility of the test item were waived. As additional information a QSAR calculation is provided. The result of the QSAR study was not considered as key value because of the available experimental study.