2-Propanone, reaction products with diphenylamine

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:

October 26, 2017 to November 23, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Commission Regulation 440/2008/EC, Method C.4-D of May 30, 2008: Manometric Respirometry Test (EEC Publication No. L 142/496, May 2008)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

OECD Guideline for Testing of Chemicals No. 301 F: "Ready Biodegradability: Manometric Respirometry Test", adopted July 17, 1992

Deviations:

no

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, domestic (adaptation not specified)

Details on inoculum:

Species/Origin: Aerobic activated sludge, microorganisms from a domestic waste water treatment plant was supplied by the sewage treatment plant Rossdorf, Germany.
Conditioning: The aerobic activated sludge used for this study was set to deposit for 30 minutes, then washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in test water and centrifuged again. This procedure was done three times. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 3.5 g dry material per litre were mixed with test water and aerated overnight. This suspension was used for the experiment.

Duration of test (contact time):

28 d

Initial conc.:

>= 24.9 - <= 25 other: mg/flask

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test Units
Type and Size: Manometric Test System with test flasks containing a volume of approximately 500 mL.
Apparatus: BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany
Principle: The test flasks were prepared and incubated at 22°C ± 1°C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 28 days using the BSB/BODSensor-System, Aqualytic Dortmund, Germany. The test flasks were closed gas-tight by a measuring head.
Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.
Identification: Each test unit was uniquely identified with the study number, treatment and replicate number.

Test Conditions
Surrounding Type: Climatised chamber
Temperature: 22°C ± 1°C
Light Conditions: Darkness
pH-Value of Test Solutions: 7.2 to 7.6 (measured at the start of the test) 7.2 to 7.6 (measured at the end of the test)
Recording: Test conditions (temperature) was recorded continuously with suitable instruments, documented in the raw data and reported in the final report. (Short-term deviations (< 2 hours) from the recommended temperature range do normally not result in major disturbances of the test performance and were not recorded.)

Test Water
Reconstituted Test Water: Analytical grade salts were added to pure water to prepare the following stock solutions:
a) 8.5 g KH2PO4, 21.75 g K2HPO4, 33.4 g Na2HPO4 x 2H2O, 0.5 g NH4Cl filled up with pure water to
1000 mL volume; The pH-value was 7.4.
b) 11.25 g MgSO4 x 7 H2O filled up with pure water to 500 mL volume
c) 18.2 g CaCl2 x 2 H2O filled up with pure water to 500 mL volume
d) 0.125 g FeCl3 x 6 H2O filled up with pure water to 500 mL volume
In order to avoid precipitation of iron hydroxide in the stock solution d), one drop of concentrated HCl per litre was added before storage.
50 mL of stock solution a) and 5 mL of the stock solutions b) to d) were combined and filled up to a final volume of 5000 mL with pure water.

Course of the Test
Preparation of Test Flasks: The amounts of test item and reference item were directly weighed into the test flasks. No emulsifiers or solvents were used, but the solutions were dispersed by stirring to achieve a homogeneous solution of the test item.
Incubation: The closed test flasks were incubated in a climatised chamber under continuous stirring. The consumption of oxygen was determined by measuring the change of pressure in the flasks. Evolved carbon dioxide was absorbed in an aqueous solution (45%) of potassium hydroxide.
Test Duration: 28 days

Test Parameters
Measurement of Oxygen: The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany) each day.
Temperature: The temperature was recorded by means of the automated software AMR Wincontrol©.
pH-Value: pH-values were measured in procedure control, a separately prepared test flask with test item (to prevent loss of test item in the test flasks) and a separately prepared test flask without test item (control) at test start and in all flasks at the end of the test, except in the abiotic and toxicity control, using a pH-electrode WTW pH 340i.

Reference substance:

benzoic acid, sodium salt

Test performance:

The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.
2-Propanone, reaction products with diphenylamine never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThODNH4 and ThODNO3).

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Biodegradation of Test Item
Percentage Biodegradation: The mean biodegradation percentage at the end of the 28-day exposure period was 0% (based on ThODNH4 and ThODNO3).
Conclusion: 2-Propanone, reaction products with diphenylamine is considered to be not readily biodegradable.

Biodegradation in the Toxicity Control
Percentage Biodegradation: In the toxicity control containing both, the test item and the reference item sodium benzoate, 26% and 25% after 14 days and to 27% and 26% after 28 days of incubation (ThODNH4.and ThODNO3). According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.
Conclusion: According to the test guidelines the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.

Abiotic Control
Oxygen Demand: The oxygen demand in the abiotic control was 0 mg/L during the test duration. There was no use to correct the degradation of the test item and toxicity control.

Results with reference substance:

Percentage Biodegradation: The reference item sodium benzoate was sufficiently degraded to 69% after 14 days and to 67% after 28 days of incubation.
Conclusion: The percentage biodegradation of the reference item confirms the suitability of the used aerobic activated sludge inoculum.

Cumulative Biochemical Oxygen Demand (mg O2/L) in Test Flasks during the Test Period of 28 Days

Time (days)	Flask No.
	1	2	3	4	5	6	7
1	0	0	0	5	45	0	35
2	0	5	5	5	70	0	60
3	5	5	5	5	80	0	70
4	5	5	5	5	90	0	80
5	10	5	5	5	105	0	110
6	10	10	10	10	110	0	115
7	10	10	10	10	120	0	120
8	10	15	10	10	125	0	130
9	10	15	10	10	125	0	130
10	10	15	10	15	130	0	135
11	10	15	15	15	130	0	135
12	15	15	15	15	130	0	135
13	15	15	15	15	130	0	135
14	15	20	15	15	135	0	135
15	15	20	15	15	135	0	140
16	20	20	15	20	135	0	140
17	20	20	20	20	135	0	140
18	20	20	20	20	140	0	145
19	20	20	20	20	140	0	150
20	20	20	20	20	140	0	150
21	20	20	20	20	140	0	150
22	25	25	25	25	140	0	150
23	25	25	25	25	140	0	150
24	25	25	25	25	140	0	150
25	25	25	25	25	140	0	150
26	25	25	25	25	140	0	150
27	25	25	30	30	145	0	155
28	25	25	30	30	145	0	155

Flasks 1 and 2: 2-Propanone, reaction products with diphenylamine

Flasks 3 and 4: inoculum control

Flask 5: reference (procedure control)

Flask 6: abiotic control

Flask 7: toxicity control

 

Percentage Biodegradation of Test Item, of Sodium Benzoate and of the Toxicity Control based on ThOD_NH4

Time (days)	Percentage Biodegradation^1
	2-Propane, reaction products with diphenylamine^1		Sodium Benzoate^2	Toxicity control^1,2
	Flask 1 [%]	Flask 2 [%]	Flask 5 [%]	Flask 7 [%]
1	0	0	25	7
2	0	0	38	12
3	0	0	43	14
4	0	0	49	16
5	2	0	58	23
6	0	0	58	23
7	0	0	64	24
8	0	2	67	26
9	0	2	67	26
10	0	1	68	26
11	0	0	67	26
12	0	0	67	26
13	0	0	67	26
14	0	2	69	26
15	0	2	69	27
16	1	1	68	26
17	0	0	67	26
18	0	0	69	27
19	0	0	69	28
20	0	0	69	28
21	0	0	69	28
22	0	0	67	27
23	0	0	67	27
24	0	0	67	27
25	0	0	67	27
26	0	0	67	27
27	0	0	67	27
28	0	0	67	27

1 ThOD_NH4of 2-Propanone, reaction products with diphenylamine: 2.900 mg O₂/mg test item

2 ThOD_NH4of sodium benzoate: 1.666 O₂/mg reference item

 

Percentage Biodegradation of Test Item, of Sodium Benzoate and of the Toxicity Control based on ThOD_NO3

Time (days)	Percentage Biodegradation^1
	2-Propane, reaction products with diphenylamine^1		Sodium Benzoate^2	Toxicity control^1,2
	Flask 1 [%]	Flask 2 [%]	Flask 5 [%]	Flask 7 [%]
1	0	0	25	7
2	0	0	38	11
3	0	0	43	13
4	0	0	49	15
5	2	0	58	22
6	0	0	58	22
7	0	0	64	23
8	0	2	67	25
9	0	2	67	25
10	0	1	68	25
11	0	0	67	25
12	0	0	67	25
13	0	0	67	25
14	0	2	69	26
15	0	2	69	26
16	1	1	68	25
17	0	0	67	25
18	0	0	69	26
19	0	0	69	27
20	0	0	69	27
21	0	0	69	27
22	0	0	67	26
23	0	0	67	26
24	0	0	67	26
25	0	0	67	26
26	0	0	67	26
27	0	0	67	26
28	0	0	67	26

1 ThOD_NO3of 2-Propanone, reaction products with diphenylamine: 3.125 mg O₂/mg test item

2 ThOD_NO3of sodium benzoate: 1.666 O₂/mg reference item

 

pH-Values at the End of the Test

Flask No.	Treatment	pH-value
1	2-Propanone, reaction products with diphenylamine	7.6
2	2-Propanone, reaction products with diphenylamine	7.6
3	Inoculum control	7.2
4	Inoculum control	7.2
5	Reference item (procedure control)	7.2

 

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The mean biodegradation percentage at the end of the 28-day exposure period was 0% (based on ThODNH4 and ThODNO3).
2-Propanone, reaction products with diphenylamine is considered to be not readily biodegradable.

Executive summary:

Summary

Title: 2-Propanone, reaction products with diphenylamine: Ready Biodegradability in a Manometric Respirometry Test

 

Guidelines: This study was designed to comply with the following methods:

− Commission Regulation 440/2008/EC, Method C.4-D of May 30, 2008: Manometric Respirometry Test (EEC Publication No. L 142/496, May 2008)

− OECD Guideline for Testing of Chemicals No. 301 F: "Ready Biodegradability: Manometric Respirometry Test", adopted July 17, 1992

 

Material and Methods:

Test Item: 2-Propanone, reaction products with diphenylamine; Batch No.: EL5D06K347

 

Test Species: Aerobic activated sludge (microorganisms from a domestic wastewater treatment plant) was supplied by the sewage treatment plant of Rossdorf, Germany.

 

Test Design: The test item 2-Propanone, reaction products with diphenylamine was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

 

Endpoints: Degradation rate of test item calculated by the oxygen consumption of the aerobic activated sludge microorganisms after 28 days of incubation.

 

Test Item Loading Rate (initial concentration in medium C₀): 102.3 mg/L corresponding to an oxygen demand of about 296.5 mg/L (ThOD_NH4) and 319.5 mg/L (ThOD_NO3)

 

Reference Item: Sodium Benzoate

 

Reference Item Loading Rate: 103.7 mg/L corresponding to an oxygen demand of about 172.7 mg/L (ThOD_NH4)

 

Test Conditions: 22°C ± 1°C, darkness

 

Results:

Biodegradation of 2-Propanone, reaction products with diphenylamine: The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.

2-Propanone, reaction products with diphenylamine never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThOD_NH4and ThOD_NO3).

Therefore, 2-Propanone, reaction products with diphenylamine is considered to be not readily biodegradable based on ThOD_NH4.and ThOD_NO3

 

Biodegradation of Sodium Benzoate: The reference item sodium benzoate was sufficiently degraded to 69% after 14 days and to 67% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

 

Biodegradation of the Toxicity Control: In the toxicity control containing both, the test item and the reference item sodium benzoate, 26% and 25% after 14 days and to 27% and 26% after 28 days of incubation (ThOD_NH4.and ThOD_NO3). According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.

Description of key information

Ready Biodegradability (Manometric Respirometry Test)

2-Propanone, reaction products with diphenylamine is considered to be not readily biodegradable based on ThOD_NH4.and ThOD_NO3

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Ready Biodegradability (Manometric Respirometry Test)

The test item 2-Propanone, reaction products with diphenylamine was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

 

Results:

Biodegradation of 2-Propanone, reaction products with diphenylamine: The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.

2-Propanone, reaction products with diphenylamine never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThOD_NH4and ThOD_NO3).

Therefore, 2-Propanone, reaction products with diphenylamine is considered to be not readily biodegradable based on ThOD_NH4.and ThOD_NO3

Biodegradation of Sodium Benzoate: The reference item sodium benzoate was sufficiently degraded to 69% after 14 days and to 67% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

Biodegradation of the Toxicity Control: In the toxicity control containing both, the test item and the reference item sodium benzoate, 26% and 25% after 14 days and to 27% and 26% after 28 days of incubation (ThOD_NH4.and ThOD_NO3). According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.

[Type of water: freshwater]