Tobacco, ext.

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

not specified

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data comes from an online compilation using secondary data sources. There is no experimental study reference, however data is cited in the database as peer reviewed, and recommended in ECHA Guidance on information requirements. Therefore it is considered as reliable, but with restrictions due to lack of details.

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

No data.

Key result

Partition coefficient:

1.17

Remarks on result:

other: pH and temperature not reported

Conclusions:

The HSDB database provides, as secondary source, some physico-chemical properties. A partition coefficient of 1.17 is cited for nicotine.

Executive summary:

The HSDB database provides, as secondary source, some physico-chemical properties. A partition coefficient of 1.17 is cited for nicotine.

Reference 2

Endpoint:

partition coefficient

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING :

The substance is a complex mixture only partially known and its physical state leads to difficulties for physico-chemical testing: It is described as viscous liquid.

GLP studies according to OECD 117 have been conducted on other substances belonging to the same group of substance (UVCB sub-type 3, where the source is biological and the process is refinement, such as: exudates, resinoids and concretes that are well-known to be very difficult to analytically assess). These studies show that this method is not appropriate for such complex substances (the study lead to one peak or to a significant part of the substance with a log Kow < 0.3 while the substance is not soluble in water). In addition, % Area is not necessarily correlated to absolute concentration in the substance if UV detection is used. Therefore we cannot guarantee the repartition of the logPow in the composition of the substance and that the results obtained by HPLC/UV-DAD are representative of the whole substance.

Moreover the physical state and the limited knowledge on the composition of such substances lead to technical issues to quantify the substance dissolved in water or in octanol media (HPLC or GC/FID do not allow to detect the totality of the test item constituents). Then OCDE 107 and 123 are also considered as not appropriate.

Finally conventional standard tests for partition coefficient endpoint intended for single substances are considered as not appropriate for such complex substances.

That is why the test has been waived for the registered substance.

Description of key information

No range of logKow representative of the test item can be determined (neither with an experimental approach nor with an estimation approach)

Additional information

The substance is a complex mixture, which contains constituents which are mostly unkown and its physical state leads to difficulties for physico-chemical testing: It is described as a viscous liquid.

GLP studies according to OECD 117 have been conducted on other substances belonging to the same group of substance (UVCB sub-type 3, where the source is biological and the process is refinement, such as: exudates, resinoids and concretes that are well-known to be very difficult to analytically assess). These studies show that this method is not appropriate for such complex substances (the study lead to one peak or to a significant part of the substance with a log Kow < 0.3 while the substance is not soluble in water). In addition, % Area is not necessarily correlated to absolute concentration in the substance if UV detection is used. Therefore we cannot guarantee the repartition of the logPow in the composition of the substance and that the results obtained by HPLC/UV-DAD are representative of the whole substance.

Moreover the physical state and the limited knowledge on the composition of such substances lead to technical issues to quantify the substance dissolved in water or in octanol media (HPLC or GC/FID do not allow to detect the totality of the test item constituents). Then OCDE 107 and 123 are also considered as not appropriate.

Finally conventional standard tests for partition coefficient endpoint intended for single substances are considered as not appropriate for such complex substances.

That is why the test has been waived for the registered substance.

In addition calculated values were provided on known constituents of the substance. However, only a range of logKow on a limited part of the composition of the substance can be calculated using QSAR estimations.Therefore it is considered that no range logKow representative of the whole test item can be determined (neither with an experimental approach nor with an estimation approach).