Hexamethylene diisocyanate, oligomers, reaction products with 3-methoxypropylamine

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 7, 2002 to November 15, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: screening test

Media:

soil

Specific details on test material used for the study:

CAS No.: 162492-07-1; Purity: treated as 100% pure; Appearance: white to off-white solid

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Soil preparation:
Representative samples of Soils I (Cranfield 115 clay loam), 11 (Cranfield 164 silt loam) and 111 (Cranfield 243 sandy loam) were taken from storage and their soil moisture content was determined after oven drying of a 50 g sample at 105 °C until constant weight.

Matrix no.:

#1

Matrix type:

clay loam

% Clay:

32.76

% Silt:

23.5

% Sand:

43.74

% Org. carbon:

1.7

pH:

> 7.4 - < 7.9

CEC:

19.6 meq/100 g soil d.w.

Matrix no.:

#2

Matrix type:

silt loam

% Clay:

11.14

% Silt:

72.91

% Sand:

15.95

% Org. carbon:

3

pH:

> 6.5 - < 7.1

CEC:

18.1 meq/100 g soil d.w.

Matrix no.:

#3

Matrix type:

sandy loam

% Clay:

13.55

% Silt:

13.12

% Sand:

73.33

% Org. carbon:

1.1

pH:

> 4.5 - < 5.6

CEC:

12.7 meq/100 g soil d.w.

Details on matrix:

Clay loam:
Water holding capacity (%): 55.3
% moisture at 1/3 bar: 30.4

Silt loam:
Water holding capacity (%): 72.8
% moisture at 1/3 bar: 41.2

Sandy loam:
Water holding capacity (%): 49.4
% moisture at 1/3 bar: 16.9

Details on test conditions:

Treatment solution:
On the day of spiking a stock solution (StA) containing 3.596 g test substance/L in methanol was prepared. The treatment solution (Spike 1) was prepared by diluting 556 uL of the stock solution to 1 L with 0.01 M aqueous CaCI2 solution. This is equivalent to 2.00 mg test substance/L. The amount of organic co-solvent (methanol) in the treatment solution was 0.06 %. The treatment solution was analysed using LC-MSMS) on the day of spiking (intermediate storage in the refrigerator at 5-10 °C) The water solubility of the test substance is 12 mg/L. The test substance concentration in the treatment solution was therefore equivalent to 17 % of the water solubility.

Key result

Sample No.:

#1

Type:

other: Kom

Value:

6 400 other: cm3/g

pH:

7.9

Matrix:

(Cranfield 115 day loam)

% Org. carbon:

2.9

Remarks on result:

other: Corresponding Koc: 110000 cm3/g

Key result

Sample No.:

#2

Type:

other: Kom

Value:

3 700 other: cm3/g

pH:

7.1

Matrix:

(Cranfield 164 silt loam)

% Org. carbon:

5.2

Remarks on result:

other: Corresponding Koc: 6330 cm3/g

Key result

Sample No.:

#3

Type:

other: Kom

Value:

730 other: cm3/g

pH:

5.6

Matrix:

(Cranfield 243 sandy loam)

% Org. carbon:

1.9

Remarks on result:

other: Corresponding Koc: 1260 cm3/g

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the test substance can be considered immobile in Cranfield 115 day loam, Cranfield 164 silt loam and Cranfield 243 sandy loam. Mean Kom values were 6400, 3700 and 730 cm3/g for the three soils, respectively. The corresponding Koc values were 110000, 6330 and 1260 cm3/g. The average Koc over the three soils was 39197 cm3/g.

Executive summary:

A study was conducted to determine the adsorption/desorption coefficient of the test substance according to OECD Guideline 106, in compliance with GLP. The adsorption behaviour was studied in three soils: Cranfield 115 (2.9% organic matter (OM), day loam), Cranfield 164 (5.2% OM, silt loam) and Cranfield 243 (1.9% OM, sandy loam). Adsorption coefficients were determined at an initial test substance concentration of 1.71 mg/L. Desorption was evaluated using two consecutive desorption steps with fresh 0.01 M aqueous CaCl2 solutions. The experiments were carried out at 20 ± 1°C in the dark. The soil supernatants were analysed using LC-MSMS. Under the study conditions, the test substance can be considered immobile in Cranfield 115 day loam, Cranfield 164 silt loam and Cranfield 243 sandy loam. Mean Kom values were 6400, 3700 and 730 cm3/g for the three soils, respectively. The corresponding Koc values were 110000, 6330 and 1260 cm3/g. The average Koc over the three soils was 39197 cm3/g (van Noorloos, 2003).

Key value for chemical safety assessment

Koc at 20 °C:

39 197

Additional information

A study was conducted to determine the adsorption/desorption coefficient of the test substance according to OECD Guideline 106, in compliance with GLP. The adsorption behaviour was studied in three soils: Cranfield 115 (2.9% organic matter (OM), day loam), Cranfield 164 (5.2% OM, silt loam) and Cranfield 243 (1.9% OM, sandy loam). Adsorption coefficients were determined at an initial test substance concentration of 1.71 mg/L. Desorption was evaluated using two consecutive desorption steps with fresh 0.01 M aqueous CaCl2 solutions. The experiments were carried out at 20 ± 1°C in the dark. The soil supernatants were analysed using LC-MSMS. Under the study conditions, the test substance can be considered immobile in Cranfield 115 day loam, Cranfield 164 silt loam and Cranfield 243 sandy loam. Mean Kom values were 6400, 3700 and 730 cm3/g for the three soils, respectively. The corresponding Koc values were 110000, 6330 and 1260 cm3/g. The average Koc over the three soils was 39197 cm3/g (van Noorloos, 2003).