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Physical & Chemical properties

Water solubility

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Endpoint:
water solubility
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source
Justification for type of information:
1. SOFTWARE
EPI Suite (US EPA)

2. MODEL (incl. version number)
WSKOWWIN v1.42 (September 2010)
WATERNT v1.01 (September 2010)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
heptacosane: CCCCCCCCCCCCCCCCCCCCCCCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
generally acknowledged source

5. APPLICABILITY DOMAIN
The model is considered suitable for alkanes with MW < 1000 g/L.

6. ADEQUACY OF THE RESULT
The estimation is provided to demonstrate that low water solubility is anticipated, based on magnitude of order.
Principles of method if other than guideline:
QSAR calculation
GLP compliance:
no
Water solubility:
ca. 0 - ca. 0 mg/L
Temp.:
25 °C
pH:
ca. 0 - ca. 14

WSKOW v1.42 Results

Log Kow  (estimated)  :  13.60

Log Kow (experimental):  not available from database

Log Kow used by Water solubility estimates:  13.60

Equation Used to Make Water Sol estimate:

  Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction

      (used when Melting Point NOT available)

     Correction(s): Hydrocarbon          -0.537

  Log Water Solubility  (in moles/L) :  -14.128

  Water Solubility at 25 deg C (mg/L):  2.834e-009

Water Sol (v1.01 est)

Minimum Solubility (log S = -12.00) Applied!

Log Water Sol (moles/L) at 25 dec C  =  -12.0000

Water Solubility (mg/L) at 25 dec C  =3.8075e-007

Conclusions:
The constituent has very low water solubility (<< 1 mg/L).
Executive summary:

The water solubility of the constituent was modelled with the both the WSKowWin and WaterNT Estimation tools, which are part of the US EPA Episuite modelling tool box.

The alkane was characterised with its SMILES code.

The predicted water solubilities at 25 °C were very low, respectively between 2.8x10-9 and 3.8x10-7 mg/L.

Endpoint:
water solubility
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source
Justification for type of information:
1. SOFTWARE
EPI Suite (US EPA)

2. MODEL (incl. version number)
WSKOWWIN v1.42 (September 2010)
WATERNT v1.01 (September 2010)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
oleyl palmitate (C16:0/C18:1): CCCCCCCCCCCCCCCC(=O)OCCCCCCCCC=CCCCCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
generally acknowledged source

5. APPLICABILITY DOMAIN
The model is considered suitable for esters with MW < 1000 g/L.

6. ADEQUACY OF THE RESULT
The estimation is provided to demonstrate that low water solubility is anticipated, based on magnitude of order.
Principles of method if other than guideline:
QSAR calculation
GLP compliance:
no
Water solubility:
ca. 0 - ca. 0 mg/L
Temp.:
25 °C
pH:
ca. 0 - ca. 14

WSKOW v1.42 Results

Log Kow  (estimated)  :  15.38

Log Kow (experimental):  not available from database

Log Kow used by Water solubility estimates:  15.38

Equation Used to Make Water Sol estimate:

  Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction

      (used when Melting Point NOT available)

     Correction(s): No Applicable Correction Factors

  Log Water Solubility  (in moles/L) :  -16.031

  Water Solubility at 25 deg C (mg/L):  4.724e-011

Water Sol (v1.01 est)

Minimum Solubility (log S = -12.00) Applied!

Log Water Sol (moles/L) at 25 dec C  =  -12.0000

Water Solubility (mg/L) at 25 dec C  = 5.069e-007

Conclusions:
The constituent has very low water solubility (<< 1 mg/L).
Executive summary:

The water solubility of the constituent was modelled with the both the WSKowWin and WaterNT Estimation tools, which are part of the US EPA Episuite modelling tool box.

The ester was characterised with its SMILES code.

The predicted water solubilities at 25 °C were very low, respectively between 4.7x10-11 and 5.1x10-7 mg/L.

Description of key information

The registered UVCB substance as a whole is considered to have very low water solubility (<< 1 mg/L), based on representative constituents of the major fraction, having solubility in the range 4.7x10-11 to 5.1x10-7 mg/L at 25°C (calculated values).

Key value for chemical safety assessment

Additional information

Considering the registered substance is an UVCB, experimental testing was considered not feasible, due to limited identification of the composition, and analytical issues expected.

Therefore, a constituent-based, Weigh-of-Evidence approach, was prefered.

Two constituents, of a different chemical family, were targeted, as representative.

For the very major, non-volatile, fraction, direct identification was not achieved, due to technical difficulties. The starting material, beeswax is a complex mixture of saturated and unsaturated linear and complex esters (27 to 40% monoesters, 9 to 23 % hydroxymonoesters, 7 to 16% diesters, 3.9% hydroxydiesters), 11 to 28% hydrocarbons, 1 to 18% saturated, unbranched free fatty acids, 4 to 8% of other substances and < 0.3% free fatty alcohols (EFSA Journal (2007) 615, 1-28). The registered substance Concrete of honeycomb cells of the bee by hexane extraction is anticipated to contain selectively extracted constituents. Hexane being a non-polar solvent, non-hydroxy esters and hydrocarbons are supposed to be predominant in the concrete. Based on the same data source, oleyl palmitate and heptacosane were selected, as major component in their family. No published data was available; predictions were calculated with both EpiSuite models, and found very low: 4.7x10-11 and 5.1x10-7 mg/L for the ester, 2.8x10-9 and 3.8x10-7 mg/L for the C27 alkane.

No data is presented for the constituents of the volatile phase, as their amount is considered negligible with regard to the assessement of the substance as a whole. Moreover, the identified constituents are similarly alkanes and alkenes, so anticipated to be of very low solubility too.

No single key value was derived for the UVCB substance, result expressed as a range was prefered, having more scientific sense.