Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-hydro-.omega.-[2-[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methylethoxy]-, ether with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (3:1)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-03-15 to 2005-07-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

adopted : 1992-06-17

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

cited as : 92/69/EWG, adopted 1992-06-31

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf. Date of taking: 7th April 2005.The sludge was washed with tap water twice, then filtrated and re-suspended in test medium. It was then aerated. The dry matter was determined as 2260 mg suspended solids/L.

Duration of test (contact time):

28 d

Initial conc.:

80 mg/L

Based on:

test mat.

Initial conc.:

250 mg/L

Based on:

ThOD/L

Details on study design:

Apparatus
Sapromat B12 Voith; consisting of a water bath holding up to 12 test vessels, 12 independent oxygen developers and a counting apparatus measuring the electricity that was needed to supply the O2.

Test Vessels
250 mL-flasks were used as test vessels. All glassware was cleaned with the laboratory cleaning agent and then rinsed with tap water (thrice), diluted HCL (once), tap water (thrice) and diluted water (thrice).

Preparation
The medium was prepared using the stock solutions. The inoculum was taken from its source, washed, aerated and the dry matter was determined. The stock solutions of test and reference item were prepared. The Sapromat was turned on, so that the water bath could heat up over night. A sufficient number of test vessels were provided. A stock solution of the reference item containing 1200.4 mg/L in deionized water was freshly prepared.

ThOD Test Item
With the formula of the compound given as C57H107N3O6*[C3H6O]n; n = 5.9, and the molecular weight M = 1273.168 g/mol, (calculated from the molecular formula) the following ThODs were calculated:
ThOD without nitrification: 2566 mg/g
ThOD with nitrification to nitrite: 2679 mg/g
ThOD with nitrification to nitrate: 2717 mg/g

ThOD Reference Item
With the formula of the compound given as C7H5NaO2, and the molecular weight MR = 144.107 g/mol, a ThOD of 1665 mg/g was calculated.

Medium
Stock Solutions
Solution a
Potassium dihydrogenphosphate (KH2PO4) 8.5 g
di-Potassium hydrogenphopsphate (K2HPO4) 21.75 g
di-Sodium hydrogenphosphate-dihydrate (Na2HPO4*2H2O) 33.4 g
Ammonia chloride (NH4CI) 0.5 g, H2Odemin. ad 1000 mL

Solution b
Calcium chloride dihydrate (CaCI2*2H2O) 36.4 g
H2Odemin. ad 1000 mL

Solution c
Magnesium sulfate heptahydrate (MgS04*7H2O) 22.5 g
H2Odemin. ad 1000 mL

Solution d
Iron(lll) chloride hexahydrate (FeCI3*6H2O) 0.25 g
Disodium-ethylen-diamin-tetraacetate dihydrate (Na2EDTA*2H2O) 0.4 g
H2Odemin. ad 1000 mL

Test Medium
The medium was freshly prepared. Composition:
Solution a 10 mL
Solution b 1 mL
Solution c 1 mL
Solution d 1 mL
H2O demin. ad 1000 mL

Reference substance:

benzoic acid, sodium salt

Test performance:

Start of the Test
The test vessels were filled with medium, then test and reference item were added to the appropriate vessels and the pH was adjusted to 7.4 ± 0.1. The vessels were incubated at 22 °C. Two hours later, the inoculum was added, the vessels were connected to the oxygen developers and the sapromat was started. Five hours after the apparatus had been turned on; the displays were checked in order to detect equilibration changes. All displays had stayed at zero.

Performance of the Test
The oxygen which was consumed by the content of the vessels was measured automatically by the test apparatus (mechanical counters measuring the current intensity needed to develop the demanded oxygen by electrolysis). The values of the displays were recorded daily (exception: week-ends). After 28 days, the test was ended. Since qualitative analysis of nitrate and nitrite gave negative results, no nitrification had taken place.

Key result

Parameter:

% degradation (O2 consumption)

Value:

48

Sampling time:

28 d

Details on results:

Please refer to the table given in any other information on results.

Results with reference substance:

Please refer to the table given in any other information on results.

The calculated percentage degradation values are presented in the following table.

Day	Ref 1	Ref. 2	Reference Mean	Test 1	Test 2	Test Mean	Abiotic Control	Toxicity Control
0	0.2	-0.2	0.0	-0.1	0.0	-0.1	0.4	-0.1
0	-0.2	0.1	0.0	0.5	0.5	0.5	0.7	0.0
1	24.4	21.2	22.8	13.8	9.7	11.7	0.7	8.4
1	37.2	37.1	37.2	19.0	14.3	16.7	0.7	13.4
2	49.1	49.9	49.5	22.7	19.3	21.0	0.7	18.8
4	68.0	70.6	69.3	29.4	26.6	28.0	0.7	28.8
5	70.6	73.9	72.3	31.9	28.7	30.3	0.7	32.0
6	73.8	78.1	75.9	33.8	30.7	32.3	0.7	39.1
7	75.5	80.4	78.0	35.4	32.0	33.7	0.7	56.2
8	77.6	82.4	80.0	36.3	33.3	34.8	0.7	59.4
9	78.8	83.9	81.3	37.0	34.3	35.7	0.7	60.9
10	80.0	85.2	82.6	41.4	36.7	39.0	2.0	62.2
11	80.8	85.9	83.4	43.7	38.1	40.9	7.7	62.8
12	82.3	86.7	84.5	45.8	39.4	42.6	13.9	63.8
13	82.7	87.4	85.0	46.4	40.6	43.5	16.9	64.5
14	82.6	87.7	85.1	47.3	41.3	44.3	18.7	66.1
15	83.0	88.5	85.8	47.1	43.3	45.2	20.5	69.1
17	84.1	89.0	86.5	47.3	48.5	47.9	22.6	70.9
18	84.4	89.3	86.9	47.9	50.1	49.0	23.4	71.5
19	84.1	89.3	86.7	47.5	51.6	49.6	24.3	71.8
20	84.7	89.8	87.2	48.2	52.7	50.5	25.1	72.5
21	84.5	89.8	87.1	48.0	52.9	50.4	25.6	72.7
22	85.1	89.7	87.4	47.9	52.8	50.3	25.6	73.0
24	84.7	90.0	87.3	47.5	53.2	50.4	26.4	73.5
25	85.3	90.3	87.8	48.2	53.6	50.9	26.4	73.7
26	85.1	90.7	87.9	47.9	53.9	50.9	27.2	73.9
27	85.0	90.6	87.8	47.8	53.8	50.8	27.2	74.0
28	84.9	90.5	87.7	47.7	54.1	50.9	27.2	73.9

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The degree of biodegradation reached an average value of 51 % after 28 days. The 10d-window began on day 1, at its end, 41 % were reached, staying below the pass level of 60% given in the OECD guideline. Thus, the test item must be classified as not readily biodegradable. Accoring to ECHA guidance IR/CSA chapter R7b, the substance fullfill the criteria for inherently biodegradation since the ThOD is above 20% within 28 days.

Executive summary:

A study was conducted according to OECD TG 301-F and Directive 92/69/EWG method C.4-D. The test item Sika Hardener LTJ was tested using a concentration of about 80 mg test item/L (equivalent to a theoretical oxygen demand of about 250 mg O2/L). Activated sludge was used as inoculum. The test was left running for 28 days. All validity criteria were met. The reference item reached the pass level of 60% on day 4.The degree of biodegradation reached an average value of 51 % after 28 days. The 10d-window began on day 1, at its end, 41 % were reached, staying below the pass level of 60%. Thus, Sika Hardener LTJ was classified as not readily biodegradable. According to ECHA guidance IR/CSA chapter R7b, the substance fulfils the criteria for inherently biodegradation since the ThOD was above 20% within 28 days.

Description of key information

Sika Hardener LTJ was classified as not readily biodegradable but fulfils the criteria for inherently biodegradation since the ThOD was above 20% within 28 days.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater

Additional information

A study was conducted according to OECD TG 301-F and Directive 92/69/EWG method C.4-D. The test item Sika Hardener LTJ was tested using a concentration of about 80 mg test item/L (equivalent to a theoretical oxygen demand of about 250 mg O2/L). Activated sludge was used as inoculum. The test was left running for 28 days. All validity criteria were met. The reference item reached the pass level of 60% on day 4. The degree of biodegradation reached an average value of 51 % after 28 days. The 10d-window began on day 1, at its end, 41 % were reached, staying below the pass level of 60%. Thus, Sika Hardener LTJ was classified as not readily biodegradable. According to ECHA guidance IR/CSA chapter R7b, the substance fulfils the criteria for inherently biodegradation since the ThOD was above 20% within 28 days.