Reaction mass of bis[4-(vinyloxy)butyl] hexane-1,6-diylbiscarbamate and 9,18-dioxo-3,8,19-trioxa-10,17-diazapentacos-1-en-25-yl [6-({[4-(vinyloxy)butoxy]carbonyl}amino)hexyl]carbamate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 August - 12 September 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study has been performed in accordance with OECD 301B (1992) and according to GLP principles. Deficiencies: on day 28 the pH in the toxicity control flask was 7.8, which is slightly above the recommended pH in the guideline (7.4±0.2). Nonetheless, 25% degradation occurred within 14 days as required by the guideline. Therefore, the test is considered to be reliable without restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

(1992)

Deviations:

yes

Remarks:

on day 28 the pH in the toxicity control flask was 7.8, which is slightly above the recommended pH in the guideline (7.4±0.2). Nonetheless, 25% degradation occurred within 14 days as required by the guideline.

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Version / remarks:

(2008)

Deviations:

yes

Remarks:

on day 28 the pH in the toxicity control flask was 7.8, which is slightly above the recommended pH in the guideline (7.4±0.2). Nonetheless, 25% degradation occurred within 14 days as required by the guideline.

Qualifier:

according to guideline

Guideline:

ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)

Version / remarks:

(1999)

Deviations:

yes

Remarks:

on day 28 the pH in the toxicity control flask was 7.8, which is slightly above the recommended pH in the guideline (7.4±0.2). Nonetheless, 25% degradation occurred within 14 days as required by the guideline.

Qualifier:

according to guideline

Guideline:

other: ISO International Standard 10634 "Water Quality - Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium" (1995)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source: Activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.
- Treatment: The freshly obtained sludge was kept under continuous aeration until further treatment. Before use, the sludge was allowed to settle (71 minutes) and the supernatant liquid was used as inoculum at the amount of 10 mL/L of mineral medium.

Duration of test (contact time):

28 d

Initial conc.:

12 mg/L

Based on:

other: Total Organic Carbon (TOC)

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: According to the OECD Guideline 301 B

- Test temperature: 21.4 - 22.2°C
- pH:
At t=0 d: 7.5-7.6
At t=28 d: 7.5–7.8
- pH adjusted: yes. At the start of the test, the pH in the blank and positive control bottles was adjusted from 7.7 to 7.5-7.6 using 1N HCl
- Aeration of test medium: Overnight prior to the start of the test. During the test the medium was aerated and stirred continously.
- Suspended solids concentration: 3.7 g/L in the concentrated sludge.

TEST SYSTEM
- Culturing apparatus: 2 litre all-glass brown coloured bottles
- Number of culture flasks/concentration:
Test suspension: containing test substance and inoculum (2 bottles).
Inoculum blank: containing only inoculum (2 bottles)
Positive control: containing reference substance and inoculum (1 bottle).
Toxicity control: containing test substance, reference substance and inoculum (1 bottle).
- Method used to create aerobic conditions: A mixture of oxygen (ca. 20%) and nitrogen (ca. 80%) was passed through a bottle, containing 0.5 - 1 litre 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts. The synthetic air was sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 mL/min).
- Details of trap for CO2: The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl (1:20 dilution from 1 M HCl (Titrisol® ampul). Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until the 28th day, for the inoculum blank and test suspension. Titrations for the positive and toxicity control were made at least 14 days. The final tritration was done on day 29.

SAMPLING
- Sampling frequency: Titration were made on day: 2, 5, 7, 9, 14, 19, 23, 27 and 29
- Sampling method: Titration of the whole volume of CO2-absorber

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Positive control: yes
- Toxicity control: yes

Reference substance:

other: Sodium acetate

Parameter:

% degradation (CO2 evolution)

Value:

0

St. dev.:

0

Sampling time:

28 d

Remarks on result:

other: Average of 2 test bottles

Details on results:

- Theoretical CO2 production: The TOC of URACROSS ZW7672P, Product ID 021116/000 was determined to be 60%. ThCO2 was calculated to be 2.20 mg CO2/mg.

- In the toxicity control 25% biodegradation occurred within 14 days (based on ThCO2). Therefore, the test substance was assumed not to inhibit microbial activity.

- Acceptability of the test:
1. The positive control substance was biodegraded by at least 60% (76%) within 14 days.
2. The difference of duplicate values for %-degradation of the test substance was always less than 20.
3. The total CO2 release in the blank at the end of the test did not exceed 40 mg/L (56 mg CO2 per 2 litres of medium, corresponding to 28 mg CO2/L).
4. The Inorganic Carbon content (IC) of the test substance (suspension) in the mineral medium at the beginning of the test was less than 5% of the Total Carbon content (TC). Since the test medium was prepared in tap-water purified by reverse osmosis (Milli-RO water, carbon levels < 500 ppb), IC was less than 5% of TC (mainly coming from the test substance, 12 mg TOC/L).

Results with reference substance:

- The ThCO2 of sodium acetate was calculated to be 1.07 mg CO2/mg. Sodium acetate was biodegraded by 76% within 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

URACROSS ZW7672P, Product ID 021116/000 was not readily biodegradable under the conditions of the modified Sturm test.

Executive summary:

The ready biodegradability of URACROSS ZW7672P, Product ID 021116/000 under the conditions of the carbon dioxide (CO2) evolution test (modified Sturm test) was investigated according to OECD guideline 301 B and GLP principles. A single test concentration of 12 mg TOC/L was tested during 28 days. Based on the obtained results, URACROSS ZW7672P, Product ID 021116/000 was not readily biodegradable. The study is considered to be reliable without restrictions.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Dec 2015 - 31 Dec 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Version / remarks:

1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: SEPA 2004, HJ/T 153-2004, The guidelines for the testing of chemicals

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: CRC-MEP, The Guidelines for the Testing of Chemicals, Degradation and Accumulation

Version / remarks:

2013

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: GB/T 21818-2008, Chemical Inherent Biodegradation-Modified MITI Test (II)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge, surface soil and surface water were sampled from ten sites distributed in four districts throughout Nanjing city.
- Method of cultivation: 1 L of sludge, soil and water were collected and mixed thoroughly. After removing floating matter, the mixture was allowed to stand and then the supernatant was filtrated through filter paper. After that the filtrate was adjusted to pH 7.0 with sodium hydroxide or phosphoric acid. Finally an appropriate volume of the filtrate was transferred to a fill-and-draw activated sludge vessel and aerated for about 23.5 h (Batch No.: IN201511041). Thirty minutes after stopping the aeration, about one third of the whole volume of supernatant was discarded. Then an equal volume of synthetic sludge (a solution at pH 7.0 containing 0.1% each of glucose, peptone and potassium orthophosphate) was added into the settled material which was then aerated again. This procedure was repeated once per day during one month.
- Pretreatment: Before use the mixture was allowed to stand, and the supernatant was removed. A small quantity of sludge was taken to be centrifuged (2500 r/min x 10 min) and then weighed. Then the sludge was dried in the oven and weighed again in order to calculate the content of dry sludge was 10%. At last 20 g of centrifuged sludge was diluted 0.5 L with basal culture medium (BSM) to get an activated sludge suspension with a concentration of 4000 mg/L (dry basis).

Duration of test (contact time):

28 d

Initial conc.:

ca. 38 mg/L

Based on:

test mat.

Remarks:

directly added to the test bottles

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium: Basal Salt Medium according to OECD302C
- Test temperature: 25 ± 1 °C
- pH: 7.34 - 7.63
- pH adjusted: no
- Aeration of dilution water: yes
- Continuous darkness: yes
- Continuous stirring: yes
- Concentration of activated sludge in test bottles: 100 mg/L

TEST SYSTEM
- Culturing apparatus: BOD bottles
- Number of culture flasks/concentration: 3 for test concentrations, 1 for abiotic control, 1 for procedure control, 1 for blank control
- Measuring equipment: BOD meter

SAMPLING
- Sampling frequency: BOD: daily; test substance analysis: 0 and 28 d

CONTROL AND BLANK SYSTEM
- Abiotic sterile control: test substance and deionised water
- Procedure control: reference substance (100 mg/L), activated sludge suspension (30 mg/L) and BSM
- Blank control: activated sludge suspension (100 mg/L) and BSM

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

3.59

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

3.61

Sampling time:

28 d

Details on results:

Recovery rate of residual amount of the test compound in the abiotic test is found to be more than 10% after 28 days.
The COD was determined to be 1.92 mg O2/mg.

Results with reference substance:

Biodegradation of sodium benzoate was 83.5% after 7 days (>40%) and 87.6% after 14 days (>65%).

Table 1: Biodegradation as BOD

Time (d)	Biodegradation (%)
	“test”				“procedure control”
	Bottle 2	Bottle 3	Bottle 4	Mean	Bottle 5
0	0	0	0	0	0
1	0.44	0.75	0.53	0.57	31.1
2	0.68	1.17	0.19	0.68	52.4
3	0.69	0.67	0.39	0.59	71.6
4	1.54	2.18	0.68	1.46	77.5
5	1.12	2.43	0.72	1.42	80.9
6	1.78	4.10	1.15	2.35	82.7
7	0.90	2.01	0.01	0.97	83.5
8	2.02	2.51	0.41	1.65	85.0
9	2.59	3.02	2.03	2.54	85.7
10	3.71	3.52	2.84	3.36	86.4
11	2.78	2.85	2.08	2.57	86.4
12	2.37	2.60	1.72	2.23	86.5
13	2.42	3.18	2.14	2.58	87.0
14	3.59	3.77	2.15	3.17	87.6
15	3.07	3.35	2.57	3.00	88.1
16	3.17	3.52	1.79	2.83	88.4
17	3.73	4.02	2.19	3.32	89.1
18	3.78	3.60	3.01	3.47	89.7
19	3.88	4.27	2.64	3.60	90.0
20	3.42	3.94	2.66	3.34	90.3
21	3.46	4.02	2.68	3.39	90.9
22	3.51	4.10	2.69	3.44	91.4
23	3.56	4.19	2.30	3.35	91.9
24	3.61	4.27	2.31	3.40	92.5
25	4.22	4.36	2.33	3.64	93.0
26	3.76	4.02	1.95	3.24	93.3
27	3.81	4.10	2.37	3.43	93.9
28	3.81	4.61	2.37	3.59	94.6

Table 2: Residual Results and Degradation of the Test Substance

Sample	Bottle	Concentration (mg/L)		Degradation (%)
		0 d	28 d
“abiotic control”	1	33.3	31.2	-
“blank”	6	0	ND*	-
“test”	2	34.0	29.6	6.99
	3	41.7	39.3	-0.01
	4	44.7	40.2	3.84
	Average			3.61

Validity criteria fulfilled:

yes

Remarks:

See 'Overall remarks" for details on validity criteria

Interpretation of results:

not inherently biodegradable

Conclusions:

Inherent biodegradation of the test substance based on the BOD results was 3.59% after 28 days. Based on the residue analysis, biodegradation was 3.61%. Therefore, the substance is considered not inherently biodegradable.

Executive summary:

The inherent biodegradability of the test substance was investigated according to OECD Guideline 302C, Modified MITI Test (II), and Chinese national Guidelines, under GLP conditions. Triplicate BOD bottles at average concentration of 38 mg/L were incubated for 28 days with activated sludge (100 mg/L) collected from 10 sites in Nanjing city, China. O2 consumption was measured daily, chemical analysis of the test substance was done at day 0 and day 28. BOD results showed 3.59% biodegradation after 28 days, chemical analysis of the test substance showed 3.61% biodegradation. Based on these results, the test substance is considered not inherently biodegradable. The study is considered reliable without restriction.

Description of key information

The substance is not readily biodegradable and not inherently biodegradable, as assessed in two studies according to OECD Guidelines 301B and 302C.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodegradability of URACROSS ZW7672P, Product ID 021116/000 under the conditions of the carbon dioxide (CO2) evolution test (modified Sturm test) was investigated according to OECD guideline 301 B and GLP principles. A single test concentration of 12 mg TOC/L was tested during 28 days. Based on the obtained results, URACROSS ZW7672P, Product ID 021116/000 was not readily biodegradable. The study is considered to be reliable without restrictions.

The inherent biodegradability of the test substance was investigated according to OECD Guideline 302C, Modified MITI Test (II), and Chinese national Guidelines, under GLP conditions. Triplicate BOD bottles at average concentration of 38 mg/L were incubated for 28 days with activated sludge (100 mg/L) collected from 10 sites in Nanjing city, China. O2 consumption was measured daily, chemical analysis of the test substance was done at day 0 and day 28. BOD results showed 3.59% biodegradation after 28 days, chemical analysis of the test substance showed 3.61% biodegradation. Based on these results, the test substance is considered not inherently biodegradable. The study is considered reliable without restriction.