Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
21 May - 29 May 1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Although the study is well described, it is not carried out according to a guideline or GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Principles of method if other than guideline:
The partition coefficient Pow is defined as the ratio of the equilibrium concentrations (c) of a dissolved substance in a two-phase system consisting of two largely immiscible solvents. In the case of n-octanol and water:

Pow = c(n-octanol)/ c(water)

For TPAB an estimation of the partition coefficient was performed, using the ratio of the maximal solubility in n-octanol (saturated with water) and water (saturated with n-octanol).
GLP compliance:
no
Type of method:
other: The partition coefficient was estimated as the quotient of the maximal solubility of TPAB in n-octanol (saturated with water) and water (saturated with n-octanol).
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name of test material (as cited in study report): TPAB
- Substance type: White crystalline solid
- Physical state: solid
- Analytical purity: 99.9%
- Lot/batch No.: T 90-4
- Storage condition of test material: In the original container at room temperature, dry and in the dark.

Study design

Analytical method:
photometric method

Results and discussion

Partition coefficientopen allclose all
Type:
Pow
Partition coefficient:
< 0.5
Temp.:
20 °C
Remarks on result:
other: Based on the maximal solubility in n-octanol (saturated with Milli-Q water) and Milli-Q water (saturated with n-octanol)
Type:
log Pow
Partition coefficient:
< -0.3
Temp.:
20 °C
Remarks on result:
other: Based on the maximal solubility in n-octanol (saturated with Milli-Q water) and Milli-Q water (saturated with n-octanol)
Details on results:
Solubility of TPAB in Milli-Q water (saturated with n-octanol):
No solid particles were observed visually in the clear, almost colourless formulations. From this, it was concluded that the solubility of TPAB in water (saturated with n-octanol) was > 1 g/mL. Analysis of the water samples of both measurements confirmed this observation. The solubility of TPAB in Milli-Q water (saturated with n-octanol) was determined to be 1.2 and 1.1 g/mL for the first and second measurement, respectively. Therefore, it was concluded that the water solubility of TPAB was > 1 g/mL.

Solubility of TPAB in n-octanol (saturated with Milli-Q water):
Visual observations revealed that not all the test substance was dissolved after the stirring period. The solubility of TPAB in n-octanol (saturated with Milli-Q water) was determined to be 0.47 g/mL and 0.45 g/mL for the first and second measurement, respectively. Hence, the n-octanol solubility of TPAB was calculated to be 0.5 g/mL as a mean value of both measurements.

Applicant's summary and conclusion

Conclusions:
The Log Pow was < -0.3.
Executive summary:

The partition coefficient was estimated as the quotient of the maximal solubility of TPAB in n-octanol (saturated with water) and water (saturated with n-octanol). This resulted in a Log Pow < -0.3.