4,4'-Methylene-bis-(3-chloro-2,6-diethylaniline)

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Qualifier:

according to guideline

Guideline:

other: Estimation using well accepted calculation methods incl. computer modeling: 1) Kenaga and Goring correlation (1980); 2) Hodson and Williams correlation; 3) Computer calculation using PCKOC, Version 1.21, Syracuse Research Corporation 4) RA TGD

Deviations:

not applicable

GLP compliance:

no

Type of method:

other: Estimation using well accepted calculation methods incl. computer modeling

Media:

soil

Radiolabelling:

no

Test temperature:

Koc was calculated

Details on study design: HPLC method:

Koc was calculated

Computational methods:

Computer calculation using PCKOC, Version 1.21, Syracuse Research Corporation

Key result

Type:

log Koc

Value:

4.29 dimensionless

Temp.:

20 °C

Remarks on result:

other: value calculated according to RA TGD (request of UK c.a.)

Key result

Type:

Koc

Value:

19 500 dimensionless

Temp.:

20 °C

Remarks on result:

other: value calculated according to RA TGD (request of UK c.a.)

The value of Koc can be estimated by various means, some of which require the input of a figure for the partition coefficient. A value of LogP = 6.28 was used for the calculation. Three such estimations are presented below, two from log Koc / Log Pow correlations and one from a computer calculated group contribution method.

1) Kenaga and Goring correlation (1980)

log Koc = 0.544 log Pow + 1.377

substituting log Pow = 6.28,

log Koc = 4. 79 or Koc = 6.2 x 104

2) Hodson and Williams correlation (1988)

log Koc = 0.827 log Pow + 0.292

substituting log Pow = 6.28,

log Koc = 5.49 or Koc = 3.1 x 10E5

3) Computer calculation using PCKOC, Version 1.21, Syracuse Research Corporation

log Koc = 6.17 or Koc = 1.5 x 10E6

The mean of the three values determined above produces Koc = 6.2 x 10E5

According to the 1987 FDA Environmental Assessment Technical Assistance Handbook, compounds with Koc values > 100 are considered to be moderately to highly mobile in soil, whereas those with values around 1000 are quite tightly bound to organic matter in soil. Therefore, as all the above estimates of Koc, are well above 1000, P5367 would be expected to be tightly bound to organic matter in soil, and hence immobile. It should be noted however, that these estimations assume that the molecule is not ionised.

On request of the UK c.a. (Environment Agency) in 1997, the Koc was also calculated according to the combined RA TGD of 1997. Therefore, the equations applicable are for 'non-hydrophobics', which is a general equation (the name is misleading), or the equation for anilines. The valid range of the latter equation is up to log Kow = 5, and therefore cannot be used in this case. Hence, using the 'non-hydrophobics' equation, the following result is obtained::

log Koc = (0.52 x 6.28) + 1.02 = 4.29

This is the final value used for environmental risk assessment.

Validity criteria fulfilled:

not applicable

Conclusions:

The log Koc was calculated to be 4.29.

Executive summary:

The calculations were performed in 1996/1997 using several estimation methods. An experimental test was technically not feasible due to insufficient solubility. On request of the c.a. of the lead notification country, the Koc value was also calculated according to the Combined RA Technical Guidance Document, obtaining a Koc of 19500 / Log Koc 4.29.

Reference 2

Endpoint:

adsorption / desorption: screening

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
The study could not be conducted due to the very low water solubility of the test item; high performance liquid chromatographic and gas chromatographic were investigated as analytical methods but neither could provide the precision required (low concentrations were dictated for the test by the poor aqueous solubility of P5367). Therefore, a test acc. OECD-method was technicallly not feasible. Therefore, the Koc was calculated.

Description of key information

Adsorption/desorption (screening):

The study could not be conducted due to the very low water solubility of the test item; high performance liquid chromatography and gas chromatography were investigated as analytical methods but neither could provide the precision required (low concentrations were dictated for the test by the poor aqueous solubility of P5367). Therefore, a test acc ording to the OECD-method was technicallly not feasible. Therefore, the Koc was calculated.

Soil adsorption coefficient:

The calculations were performed in 1996/1997 using several estimation methods. An experimental test was technically not feasible due to insufficient solubility. On request of the c.a. of the lead notification country, the Koc value was also calculated according to the Combined RA Technical Guidance Document, obtaining a Koc of 19500 / Log Koc 4.29.

Key value for chemical safety assessment

Koc at 20 °C:

19 500