Decanoic acid, mixed esters with heptanoic acid, octanoic acid and pentaerythritol

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:

12 Dec. 2016 to 12 Jan. 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

OECD Guidelines for the Testing of Chemicals, Part 301 B, adopted 17. Jul. 1992 “CO2-Evolution-Test (Modified STURM Test)“

Deviations:

yes

Remarks:

See "Any other information" for details

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Council Regulation (EC) No. 440/2008, Method C.4-C, adopted 30. May 2008 “CO2-Evolution-Test”

Deviations:

yes

Remarks:

See "Any other information" for details

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

No further details specified in the study report.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Specification
Activated sludge from a biologic sewage treatment plant was used as inoculum. The chosen plant is treating mostly domestic sewage.

Source and Pre-Treatment of inoculum
Source
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf.
Date of collection: 09. Dec. 2016, batch no: 20161209.

Pre-Treatment
The sludge was filtered, washed with tap water (2x), then washed with and re-suspended in test medium. Test medium was then aerated until use. Dry matter was measured and found to make up 4160 mg suspended solids/L.

Duration of test (contact time):

28 d

Initial conc.:

28.8 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Preparations
Test medium was prepared from the stock solutions. The stock solution for the positive control was prepared and its DOC was measured. The inoculum was taken from its source, washed, aerated and the dry matter was determined.
The test vessels were filled with medium and inoculum. Then, all flasks were aerated for 72 hours with purified, CO2-free, moistened air to purge the system of CO2.

Experimental Parameters
Flask volume: 1500 mL
Apparatus: blanks 2, containing mineral medium only; Blank Controls 2, containing mineral medium and inoculum; Positive control flasks 2, containing positive control, mineral medium and inoculum; Test flasks 2, containing test item, mineral medium and inoculum; Abiotic control 1, containing test item, mineral medium and HgCl2; Toxicity control 1, containing test item, positive control, mineral medium and inoculum
Inoculum concentration: 25.0 mg/L
Temperature: 18.7 – 21.7 °C
Duration: 28 days
The test was performed with a nominal start concentration of 20 mg organic carbon/L.

Apparatus
The test vessels were aerated with purified (by activated charcoal), CO2-scrubbed, moistened air. The scrubbing of carbon dioxide was achieved by bubbling purified air through a flask containing 1.5 M NaOH. To control for the absence of CO2, the air was then led through a flask containing a solution of Ba(OH)2 before reaching the test vessels.
Magnetic stirrers were used to prevent deposition of inoculum.
The emitted CO2 was trapped in 0.25 M NaOH. Two scrubbers containing 100 mL each were connected in series to the test vessels. The initial IC value of the 0.25 M NaOH was separately determined in each flask.

Sampling
From each front scrubber flask, 10 samples were taken in order to determine the emitted CO2 (on day 0, 2, 4, 7, 9, 11, 15, 17, 23 and 29). The sample volume collected was 1 mL.
The resulting change in the volume of the front flask was considered in the calculation of emitted CO2.
On day 28, 5 mL HCl 2 M was added to each test flask to drive off dissolved CO2. On day 29, samples were obtained from both scrubber flasks.

Reference substance:

aniline

Test performance:

Results for the Test Item Hatcol 3178
The test item Hatcol 3178 is considered as “readily biodegradable“.
The degree of biodegradation reached 84 % after 28 days.
The 10-day-window began on day 3, at its end, 63 % degradation were reached, surpassing the pass level of 60 % given in the OECD guideline.
Because the test item is a mixture, the 10-day window does not have to be taken into account. Therefore, regardless of the 10-day-window, the test item is considered as “readily biodegradable”.
Abiotic degradation was not observed.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

84

Sampling time:

28 d

IC values in mg/L of apparatus blanks, blank controls, front scrubber

Day	Apparatus blank 1	Apparatus blank 2	Blank Control 1	Blank Control 2
0	3.04	2.05	1.93	2.16
2	4.55	3.13	7.61	15.85
4	6.87	5.17	23.43	28.66
7	9.01	7.04	38.63	41.70
9	10.89	8.46	45.54	51.55
11	12.09	9.54	51.96	59.11
15	14.95	16.28	60.24	69.91
17	17.65	49.76	59.85	72.69
23	17.02	16.16	66.23	78.02
29	23.20	22.13	77.35	87.36

 

IC values in mg/L of positive control, test flasks, front scrubber

Day	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
0	2.10	1.83	2.40	2.14	1.77	38.90
2	10.47	15.56	15.70	19.44	4.80	24.07
4	92.00	100.00	102.88	79.42	7.97	143.21
7	228.52	244.23	193.17	91.36	9.30	346.65
9	274.76	302.29	238.80	184.27	10.08	455.65
11	299.85	323.59	256.40	229.33	11.49	521.79
15	323.53	343.87	295.33	264.04	14.98	583.43
17	343.19	372.47	317.75	274.18	15.55	615.88
23	353.34	366.90	330.87	304.30	14.72	631.13
29	371.59	387.06	360.78	358.48	19.19	630.85

 

IC values in mg/L of blank controls, apparatus blanks, back scrubber

Day	Apparatus blank 1	Apparatus blank 2	Blank Control 1	Blank Control 2
0	2.84	1.87	1.87	1.89
29	3.84	2.92	3.03	4.51

 

IC values in mg/L of positive control, test flasks, back scrubber

Day	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
0	2.07	2.00	1.98	2.35	2.06	2.12
29	2.59	3.20	5.47	4.08	2.97	3.19

 

Net IC-values in mg/L of front scrubber flasks

Day	Blank Control 1	Blank Control 2	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
0	1.9	2.2	2.1	1.8	2.4	2.1	1.8	38.9
2	6.3	14.6	9.2	14.3	14.4	18.1	36.5	22.8
4	20.0	25.2	88.5	96.5	99.4	75.9	4.5	139.7
7	33.2	36.2	223.0	238.8	187.7	85.9	3.8	341.2
9	38.4	44.4	367.6	295.2	231.7	177.1	3.0	448.5
11	43.7	50.8	291.6	315.3	248.1	221.1	3.2	513.5
15	47.2	56.8	310.5	330.8	282.3	251.0	1.9	570.4
17	28.7	41.5	312.0	341.3	286.6	243.0	-15.6	584.7
23	52.2	64.0	339.3	352.9	316.8	290.3	0.7	617.1
29	57.2	57.2	351.5	366.9	340.7	338.4	-0.9	610.7

 

Net IC-values in mg/L of back scrubber flasks

Day	Blank Control 1	Blank Control 2	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
0	1.9	1.9	2.1	2.0	2.0	2.4	2.1	2.1
29	2.0	3.5	1.6	2.2	4.4	3.1	1.9	2.2

 

pH in Test flasks on day 28

Day	Blank Control 1	Blank Control 2	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
28	7.3	7.3	7.1	7.1	7.3	7.3	6.7	7.1

 

Estimated carbon in mg/L

Day	Blank Control 1	Blank Control 2	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
2	0.29	0.82	0.47	0.82	0.79	1.06	0.11	-1.06
4	1.18	1.50	5.65	6.19	6.34	4.82	0.18	6.59
7	2.02	2.20	14.29	15.32	11.98	5.42	0.13	19.55
9	2.33	2.70	16.99	18.77	14.67	11.20	0.08	26.22
11	2.64	3.08	18.33	19.85	15.56	13.86	0.09	30.6
15	2.84	3.43	19.32	20.62	17.54	15.59	0.01	33.30
17	1.66	2.44	19.22	21.05	17.62	14.93	-1.08	33.84
23	3.08	3.79	20.68	21.53	19.28	17.67	-0.07	35.46
29	3.36	4.05	21.16	22.16	20.68	20.44	-0.17	34.69

 

Degradation values in %

Day	Positive Control 1	Positive Control 2	Positive Control Mean	Test 1	Test 2	Test Mean	Abiotic Control	Toxicity Control
2	-0.4	1.3	0.5	1.2	2.5	1.8	0.6	-4.1
4	21.5	24.2	22.9	24.8	17.4	21.1	0.9	13.1
7	60.9	66.0	63.4	49.0	16.5	32.8	0.7	43.7
9	72.3	81.2	76.8	60.4	43.4	51.9	0.4	59.4
11	77.3	84.9	81.1	63.1	55.0	59.0	0.5	68.1
15	80.9	87.4	84.2	71.6	62.3	66.9	0.0	75.6
17	85.8	95.0	90.4	77.3	64.4	70.9	-5.3	79.7
23	86.2	90.4	88.3.	78.7	71.2	74.9	-0.3	80.2
29	87.2	92.2	89.7	84.3	83.7	84.0	-0.8	77.6

 

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item Hatcol 3178 was tested using a nominal concentration of 20 mg of organic carbon/L (corresponding to 28.8 mg Hatcol 3178/L) in test medium following OECD 301B and EU-Method C.4-C.
Aniline was chosen as positive control.
Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L).
The test was left running for 28 days.
All validity criteria were met. Degradation of the positive control was 63 % after 7 days.
The following data were determined for the test item Hatcol 3178:
10-day-window: day 3 – 13
degradation at the end of 10-day-window 63 %
degradation at the end of the test 84 %
pass level following guideline 301B: 60% at the end of 10-day-window for pure substances respective 60 % at the end of the test for mixtures.
Therefore, when applying the 10-day-window, Hatcol 3178 is readily biodegradable following OECD 301B/EU C.4-C.
Because the test item is a mixture, the 10-day-window does not have to be taken into account. As the final degradation surpassed 60% in the course of the test, Hatcol 3178 is to be considered as readily biodegradable.

Executive summary:

The test item Hatcol 3178 was tested using a nominal concentration of 20 mg of organic carbon/L (corresponding to 28.8 mg Hatcol 3178/L) in test medium following OECD 301B and EU-Method C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L).

The test was left running for 28 days.

All validity criteria were met.

 

Degradation behaviour of positive control and toxicity control was normal. Abiotic degradation was not observed. Both replicates of the test item showed very good correspondence.

If degradation in the toxicity flask is below 25% after 14 days, the test item can be considered as toxic towards the inoculum. Observed degradation in the toxicity flask was 74 % after 14 days, the test item can be stated as “not toxic towards the inoculum in a concentration of 28.7 mg/L”.

For pure substances, ready degradability is defined in the guidelines as degradation surpassing

60% within 10 days after reaching a level of 10%.

Because the test item is a mixture, the 10-day-window does not have to be taken into account.

Therefore, regardless of the 10-day-window, the test item Hatcol 3178 is considered as “readily biodegradable” as the pass level of 60 % was surpassed at the end of the test.

No observations were made which might cause doubts concerning the validity of the study outcome.

 

Degradation of the positive control was 63 % after 7 days.

The following data were determined for the test item Hatcol 3178:

10-day-window: day 3 – 13

degradation at the end of 10-day-window 63 %

degradation at the end of the test 84 %

pass level following guideline 301B: 60% at the end of 10-day-window for pure substances respective 60 % at the end of the test for mixtures

Therefore, when applying the 10-day-window, Hatcol 3178 is readily biodegradable following OECD 301B/EU C.4-C.

Because the test item is a mixture, the 10-day-window does not have to be taken into account. As the final degradation surpassed 60% in the course of the test, Hatcol 3178 is to be considered as readily biodegradable.

Description of key information

As the final degradation surpassed 60% in the course of the test, Hatcol 3178 is to be considered as readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The test item Hatcol 3178 was tested using a nominal concentration of 20 mg of organic carbon/L (corresponding to 28.8 mg Hatcol 3178/L) in test medium following OECD 301B and EU-Method C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L).

The test was left running for 28 days.

All validity criteria were met.

 

Degradation behaviour of positive control and toxicity control was normal. Abiotic degradation was not observed. Both replicates of the test item showed very good correspondence.

Because the test item is a mixture, the 10-day-window does not have to be taken into account.

Therefore, regardless of the 10-day-window, the test item Hatcol 3178 is considered as “readily biodegradable” as the pass level of 60 % was surpassed at the end of the test.

No observations were made which might cause doubts concerning the validity of the study outcome.

 

Degradation of the positive control was 63 % after 7 days.

The following data were determined for the test item Hatcol 3178:

10-day-window: day 3 – 13

degradation at the end of 10-day-window 63 %

degradation at the end of the test 84 %

pass level following guideline 301B: 60% at the end of 10-day-window for pure substances

respective 60 % at the end of the test for mixtures

Therefore, when applying the 10-day-window, Hatcol 3178 is readily biodegradable following OECD 301B/EU C.4-C.

Because the test item is a mixture, the 10-day-window does not have to be taken into account. As the final degradation surpassed 60% in the course of the test, Hatcol 3178 is to be considered as readily biodegradable.