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Physical & Chemical properties

Partition coefficient

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Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Type:
log Pow
Partition coefficient:
2.76
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No data reported
Conclusions:
The log Kow of isobutane is 2.76.
Executive summary:

The log Kow of isobutane is 2.76. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
2.89
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No data reported
Conclusions:
The log Kow of butane is 2.89.
Executive summary:

The log Kow of butane is 2.89. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
1.81
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No data reported
Conclusions:
The log Kow of ethane is 1.81.
Executive summary:

The log Kow of ethane is 1.81. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP status not known, information from a published handbook, acceptable with restrictions
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
no data reported
Type of method:
shake-flask method to: flask method
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
1.13
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No further details provided.
Conclusions:
The log Kow of ethylene is 1.13.
Executive summary:

The log Kow of ethylene is 1.13. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
1.09
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No data reported
Conclusions:
The log Kow of methane is 1.09.
Executive summary:

The log Kow of methane is 1.09. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
2.36
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
No data reported
Conclusions:
The log Kow of propane is 2.36.
Executive summary:

The log Kow of propane is 2.36. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data
GLP compliance:
not specified
Type of method:
other: No data reported
Partition coefficient type:
octanol-water
Type:
log Pow
Partition coefficient:
2.33
Temp.:
20 °C
pH:
7
Remarks on result:
other: Temperature and pH not reported so assumed to be standard temperature and neutral pH
Details on results:
The value reported is for both the cis and trans isomers of 2-butene.
Conclusions:
The log Kow of 2-butene isomers is 2.33.
Executive summary:

The log Kow of 2-butene isomers is 2.33. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
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
Justification for type of information:
Episuite and the KOWWIN models are well documented and commonly used QSAR for predicting the partition coefficient of chemicals. Substances within LOA fall within the applicability domain of these models and they have been recommended by ECHA in the Information Requiement Guidelines.
Qualifier:
no guideline required
Principles of method if other than guideline:
KOWWIN (the Log Octanol-Water Partition Coefficient Program) estimates the logarithmic octanol-water partition coefficient (log P) of organic compounds and gives relevant experimental data, if available. KOWWIN requires only a chemical structure to estimate a log P using an atom/fragment contribution method. The model is based on methodlogies laid out in Meylan et al. (1995).
Key result
Type:
log Pow
Partition coefficient:
1.78
Remarks on result:
other: Result from QSAR prediciton
Conclusions:
The predicted log Kow for Carbon Monoxide is 1.78.
Executive summary:

The log Kow for carbon monoxide has been predicted using the EPISUITE v4.11 (2017) program that uses methodology described by Meylan et al. (1995). The predicted log Kow for Carbon Monoxide is 1.78.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: Not reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
1.99
Remarks on result:
other: pH not specified
Details on results:
No further information provided
Conclusions:
The log Kow of 1,3-butadiene is 1.99.
Executive summary:

The log Kow of 1,3-butadiene is 1.99. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
shake-flask method to: flask method
Remarks:
No further details reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
2.4
Remarks on result:
other: Temperature and pH not specified
Details on results:
No further information provided

No further information provided.

Conclusions:
The log Kow of 1-butene is 2.4.
Executive summary:

The log Kow of 1-butene is 2.4. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: Not reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
1.77
Remarks on result:
other: pH not specified
Details on results:
No further information provided
Conclusions:
The log Kow of 1-propene is 1.77.
Executive summary:

The log Kow of 1 -propene is 1.77. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: Not reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
2.34
Remarks on result:
other: pH not specified
Details on results:
No further information provided
Conclusions:
The log Kow of 2-methylpropene is 2.34.
Executive summary:

The log Kow of 2-methylpropene is 2.34. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Up to 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline, Information from published handbook, acceptable with restrictions.
Principles of method if other than guideline:
The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to Exploring QSAR, Hydrophobic, Electronic and Steric Constants states that it is an extensive compilation of published data. Each record is evaluated and the preferred value is identified for each substance. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.
GLP compliance:
not specified
Remarks:
No data reported
Type of method:
other: Not reported
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
3.39
Remarks on result:
other: pH not specified
Details on results:
No further information provided
Conclusions:
The log Kow of pentane is 3.39.
Executive summary:

The log Kow of pentane is 3.39. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Description of key information

The partition coefficient of the constituents in the category ranges from 1.09 to 3.39.

Key value for chemical safety assessment

Log Kow (Log Pow):
2.17
at the temperature of:
20 °C

Additional information

Data from Hansch (1995) were available for the substances methane, ethane, ethylene, propane, 1-propene, 2-methylpropane (isobutane), 2-methylpropene, butane, 1-butene, 2-butene, 1,3-butadiene and pentane. This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use for this endpoint. QSAR estimate data was calculated for carbon monoxide.

The experimental partition coefficient of methane is 1.09, ethane is 1.81, ethylene is 1.13, propane is 2.36, 1-propene is 1.77, 2-methylpropane (isobutane) is 2.76, 2-methylpropene is 2.34, butane is 2.89, 1-butene is 2.4, 2-butene is 2.33, 1,3-butadiene is 1.99 and pentane is 3.39. The predicted log Kow of carbon monoxide is 1.78.

The data available for these substances can be read across to other members of the category. The mean of the partition coefficient values for the category is 2.17 and this has been used to complete the 'key value for chemical safety assessment'. This value may change for streams that do not contain 1,3 -butadiene.