7,7-dimethyl-3-oxa-6-azaoctan-1-ol

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Initiated on 27.03.96 and completed on 27.03.96

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Signature date: 19.04.96

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

0.1 - 1.7

Temp.:

35 °C

pH:

ca. 7

Details on results:

The HPLC (see results table below) show that the test substance consists of 8 compounds (peaks), where each compound corresponds to one n-octanol/water partition coefficient (log Pow value). For compounds (peaks) with retention times lower than thiourea (to = 0.71), the log k <0, i.e. log Pow <0. According to SFT, each compound contributing to ≥ 1 % to the test substance, should be taken into consideration.

According to 0SPAR (1995), the Pow range for complex substances which are a group of homologs needs to be stated, and the Pow calculated based on the weighted average.
The log Pow of the test substance is therefore presented by the
Log Pow of 0.1-1.7. Based on the single Pow values for each of the 8 compounds/peaks in the test substance and the corresponding area % (see Table), the calculated weighted average log Pow = 1.7.
It should be noted that 0SPAR (1995) has not yet defined how the weighted average log Pow should be calculated, and that the calculation method used is presently being evaluated.

Log Pow- values for test substance

Compound/peak no.	Compound/peak retention time (min)	Log Pow	Area % under peak
1	0.89	0.1	5
2	1.10	1.0	2
3	1.36	1.7	92
4	3.33	3.3	<1
5	3.88	3.5	<1
6	6.06	4.2	<1
7	7.02	4.3	<1
8	8.75	4.6	<1

Weighted average log Pow calculation:

log (10^0.1 x 5 + 10^1.0 x 2 + 10^1.7 x 92) / (5 + 2 +92)) = 1.7

The reference substance, p-Cresol, had a log Pow value of 1.3

The test is considered valid if the following requirement is met:

The values of log Pow of the test substance derived from the different measurements fall within a range of ± 0.1 log units. In this test, the criterion was met.

Conclusions:

The bioaccumulation potential for the test substance has been determined by the log Pow of 0.1-1.7 and the calculated weighted average log Pow of 1.7, covering the compounds (peaks) in the chromatogram contributing to ≥ 1 % to the test substance.

According to OSPAR (1995), if the calculated or measured log Pow::: 3 and the molecular weight is < 600, a test substance is assumed to bioaccumulate, unless an experimental bioconcentration test indicates the opposite. The test substance is, according to OSPAR (1995), not considered to bioaccumulate since the weighted average log Pow < 3.

Executive summary:

Bioaccumulation testing has been performed on the test substance based on OECD guideline 117: "Determination of the n-octano/lwater partition coefficient by HPLC".

The bioaccumulation potential for the test substance has been determined by the log Pow of 0.1-1.7 and the calculated weighted average log Pow of 1.7, covering the compounds (peaks) in the chromatogram contributing to ≥ 1 % to the test substance.

The test substance is, according to OSPAR (1995), not considered to bioaccumulate, since the weighted average log Pow < 3.

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not reported in the data over 12 years old provided by ECHA.

Reliability:

other: These data were provided by ECHA (inquiry no: 06-0000023417-70-0000) from ECHA databases, submitted in the framework of a registration at least 12 years previous (per Article 25(3) of REACH Regulation). Reliability of the study was not provided by ECHA.

Qualifier:

according to guideline

Guideline:

other: US EPA CS-1400

Deviations:

not specified

GLP compliance:

yes

Type of method:

other: Not reported.

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

-2.6

Temp.:

20 °C

pH:

ca. 7

Conclusions:

log Pow -2.6 at 20 deg C.

Description of key information

Key Study (Bakke, 1996): log Pow of 1.7 
Supporting study (Exxon, 1984): log Pow -2.6

Key value for chemical safety assessment

Log Kow (Log Pow):

1.7

at the temperature of:

35 °C

Additional information

In a study conducted using the HPLC screening test for n-octanol/water partition coefficient determination (Bakke, 1996), three significant peaks associated with the test item were observed and use to derive a weighted average partition coefficient. The log Pow for the substance ranged from 0.1 - 1.7, and the calculated weighted average log Pow was 1.7.