3-[(phenylcarbamoyl)amino]phenyl 4-methylbenzenesulfonate

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:

15 May 2018 - 12 June 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Storage conditions: The test material was stored in a dark storage place at room temperature.

Oxygen conditions:

anaerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

- Source of inoculum/activated sludge: 10 locations in Japan (samples were from surface water and surface soil of rivers, lake and inland sea, and return sludge from sewage plants).
- Storage conditions: Prepared and controlled in test facility.
- Method of cultivation: Cultivated for 19 hours after feeding with synthetic sewage. Synthetic sewage was prepared: glucose, peptone, and potassium dihydrogenphosphate dissolved in purified water, pH of the solution adjusted to 7.0 ± 1.0.
- Concentration of sludge: 30 mg/L (as concentration of suspended solids). Additive amount of the activated sludge into the test vessel was 2.37 mL on the basis of the concentration of suspended solids in the activated sludge which was determined to be 3800 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

BOD (Biochemical oxygen demand)

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Medium: Basal culture medium (pH adjusted to 7.0).
- Test temperature: 25 ± 1 °C
- pH: 7.0
- pH adjusted: yes
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes
- Test solutions
1) Test solution (water + test material) (n = 1, Vessel No. 1)
2) Test solution (sludge+ test material) (n = 3, Vessel Nos. 3, 3, 4)
3) Test solution (sludge + 100 mg/L aniline) (n = 1, Vessel No. 6)
4) Test solution (control blank) (n = 1, Vessel No. 5)

TEST SYSTEM
- Measuring equipment: Closed system oxygen consumption measuring apparatus (No. CM-065). Temperature controlled bath with measuring unit.
- Incubation temperature: measured and recorded once a day.
- Vessel: Glass vessel
- Absorbent for carbon dioxide: Soda lime No.1 (FUJIFILM Wako Pure Chemical).

CONTROL AND BLANK SYSTEM
- In one test vessel the basal culture medium (the volume subtracting the volume (2.37 mL) of activated sludge from 300 mL) was added. The activated sludge was added so that the concentration of suspended solid reached 30 mg/L.

OBSERVATIONS AND MEASUREMENTS
Ath the start and the end of the incubation, the appearances of the test solution (water + test material), (sludge + test material) and (control blank) were observed and recorded. During the incubation period the soultions were observed daily.
During the incubation period, BOD of the test solutions was measured continuously with a closed system oxygen consumption measuring apparatus. The incubation temperature was measured daily.

CALCULATION OF PERCENTAGE BIODEGRADATION
- Calculation of percentage biodegradation by BOD:

Percentage biodegradation (%) = [(BOD - B)/TOD] X 100

Where
BOD: Biochemical oxygen demand in the test solution (sludge + test material) (experimental: mg)
B: Biochemical oxygen demand in the test solution (control blank) (experimental: mg)
TOD: Theoretical oxygen demand required when the test material was completely oxidised (calculated: mg). In the calculation of TOD, nitrogen form was treated as NO2.

- Calculation of percentage biodegradation of test material:

Percentage biodegradation (%) = [(Sw - Ss)/Sw] x 100

Where:
Ss: Residual amount of the test material in the test solution (sludge + test material) (experimental: mg).
Sw: Residual amount of the test material in the test solution (water + test material) (experimental: mg).

Reference substance:

aniline

Test performance:

This study met the validity criteria.

Key result

Parameter:

other: % degradation by BOD

Value:

0

Sampling time:

28 d

Key result

Parameter:

other: % degradation by HPLC

Value:

1

Sampling time:

28 d

Details on results:

The average percentage biodegradation was 0 % by BOD and 1 % by HPLC. Moreover, no peak corresponding to a degradation product was detected on the HPLC chromatograms. These results showed that the test material was not biodegraded under the test conditions of this study.

Validity of the test

		Value in the test	Value of criterion
Difference between extremes of replicate values of percentage biodegradation in test solution (sludge + test material) on Day 28	Percentage biodegradation by BOD	0 %	< 20 %
	Percentage biodegradation of test material	1 %
Percentage biodegradation by BOD in test solution (sludge + aniline)	On Day 7	76 %	> 40 %
	On Day 14	94 %	> 65 %
Biochemical oxygen demand in test solution (control blank)	On Day 28	23 mg/L ^*2	< 60 mg/L

*2: Measurement value (6.8 mg) / (test volume (300 mL) / 1000)) = 23 mg/L

 

Appearance of the test solutions

	Test solution	Appearance (visual)	pH
At the start of incubation	Water + test material	The test material was not dissolved. The test solution was colourless.	-
	Sludge + test material	The test material was not dissolved. The test solution was colourless.	-
	Control blank	Insoluble compound except the sludge was not observed. The test solution was colourless.	-
At the end of incubation	Water + test material	Insoluble compound was observed. The test solution was colourless.	Vessel No. 1: 7.6
	Sludge + test material	Insoluble compound in addition to the sludge observed. Growth of the sludge was not observed. The test solution was clouded	Vessel No. 2: 7.2 Vessel No. 3: 7.2 Vessel No. 4: 7.2
	Control blank	Insoluble compound except the sludge was not observed. The test solution was colourless.	Vessel No. 5: 7.2

 

Analytical results of the test solutions on Day 28

		Water + test material	Sludge + test material			Theoretical amount
		Vessel No. 1	Vessel No. 2	Vessel No. 3	Vessel No. 4
BOD^*3	mg	2.0	-0.4	-0.4	-0.6	63.9
Residual amount and percentage residue of test material (HPLC	mg	29.7	29.5	29.5	29.3	30.0
	%	99	98	98	98	-

*3: The value of the test solution (control blank) was subtracted from the values of the test solutios (sludge + test material)

 

Percentage biodegradation

		Sludge + test material
		Vessel No. 2	Vessel No. 3	Vessel No. 4	Average
Percentage biodegradation by BOD	%	-1	-1	-1	0 (-1)^*4
Percentage biodegradation of test material (by HPLC)	%	1	1	2	1

*4: The average percentage biodegradation was regarded as 0 % because the calculated average value shown in the parentheses was negative.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Under the conditions of this study, no biodegradation of the test material was observed.

Executive summary:

The ready biodegradability of the test material was investigated in accordance with the standardised guidelines OECD 301C, under GLP conditions. The percentage biodegradation was calculated by the measurement of biochemical oxygen demand (BOD) with a closed system oxygen consumption measuring apparatus, as well as the determination of the test material by HPLC. The test system consisted of activated sludge cultivated for 19 hours after feeding with synthetic sewage.

The average percentage biodegradation was 0 % by BOD and 1 % by HPLC. Moreover, no peak corresponding to a degradation product was detected on the HPLC chromatograms. Under the conditions of this study, no biodegradation of the test material was observed. 

The test was considered valid as it met all the values in the criteria. 

Description of key information

Under the conditions of this study, no biodegradation of the test material was observed. 

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

The ready biodegradability of the test material was investigated in accordance with the standardised guidelines OECD 301C, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997). The percentage biodegradation was calculated by the measurement of biochemical oxygen demand 9BOD) with a closed system oxygen consumption measuring apparatus, as well as the determination of the test material by HPLC. The test system consisted of activated sludge cultivated for 19 hours after feeding with synthetic sewage. The test was considered valid as it met all the values in the criteria. The average percentage biodegradation was 0 % by BOD and 1 % by HPLC. Moreover, no peak corresponding to a degradation product was detected on the HPLC chromatograms. Under the conditions of this study, no biodegradation of the test material was observed.