Benzyltrimethylammonium hydroxide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 18 April 2018 to 07 May 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The substance can be produced through different process routes, yielding solutions in water or organic solvent (e.g. methanol or ethylene glycol).
It was initially unclear how to register the substance (mono-constituent or multi-constituent substance) and which manufactured substance to test to fulfil the REACH data requirements. After consultation with the ECHA helpdesk, the test program was started with the manufactured substance of the Lead registrant (solvent: methanol) in which the highest amount of solvent could be removed without causing degradation of the substance. This resulted in the selection of a solution of 56-57% BTMAOH in methanol as test substance.
During the course of the test program, and in order to aid meaningful risk assessment, after consultation with ECHA and upon ECHA's recommendation, it was considered to be more appropriate to test the water-based manufactured substance. As a consequence, some testing was performed with a BTMAOH solution in methanol, and some testing was performed with a BTMAOH solution in water.

The current entry reflects a test performed with a water-based test solution.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

-3

Temp.:

20 °C

pH:

7

Key result

Type:

Pow

Partition coefficient:

0.001

Temp.:

20 °C

pH:

7

Details on results:

- Concentration analysed in the stock solution was 1.03 g/L.
- Nominal quantity of the substance in each test sample: 2.06 mg.
- Recovery (range) for the test samples: 100-104%.
- The log Pow values were within the criterion range of ± 0.3 log units (see table below)

Table: Shake-flask results

 

Ratio n-octanol : buffer pH 7 [v:v]	Analyzed concentration		Pow	log Pow	pH
	n-octanol [g/L]	buffer pH 7 [g/L]	individual
1:1	0.000400	0.344	1.2E-3	-2.9	7.1
	0.000481	0.350	1.4E-3	-2.9	7.1
1:2	0.000388	0.266	1.5E-3	-2.8	7.1
	0.000250	0.266	9.4E-4	-3.0	7.1
2:1	0.000457	0.528	8.7E-4	-3.1	7.1
	0.000478	0.525	9.1E-4	-3.0	7.1
Mean			1.1E-3	-3.0
Standard deviation			2.5E-4

Conclusions:

The log Pow of BTMAOH at pH 7 and 20°C was determined to be -3.0.

Executive summary:

The shake-flask method according to EC A.8, OECD 107 and OPPTS 830.7550 was performed (GLP-study). The study was performed with 20% BTMAOH in water. Quantitative analysis was performed on BTMAOH by HPLC-UV. The Pow of BTMAOH at pH 7 and 20°C was determined to be 1.1E-3 with a standard deviation of 2.5E-4. log Pow = -3.0.

Description of key information

The log Pow of the registered substance BTMAOH at pH 7 and 20°C was determined to be -3.0.

Key value for chemical safety assessment

Log Kow (Log Pow):

-3

at the temperature of:

20 °C

Additional information

Determined using the shake-flask method, performed with 20% BTMAOH in water. Quantitative analysis was performed on BTMAOH by HPLC-UV.