N,N’-di[3-(p-toluene sulfonyl)oxy]phenyl urea

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

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:

July 17, 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Testing Methods for New Chemical Substances (301C) - Japan CSCL

Version / remarks:

March 29, 2018

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): 10 locations in Japan (samples from: surface water, surface soil of rivers, lake, and inland sea, return sludge from sewage plants)

The activated sludge was cultivated for 18.5 hours after feed with synthetic sewage. Synthetic sewage was prepared as follows: glucose, peptone and potassium dihydrogenphosphate were dissolved in purified water, pH adjusted to 7.0 +/- 1.0

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Remarks:

The test substance did not dissolve.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: The basal culture medium (5L) was prepared at the same proportion as the following method: each 3µ aliquots of A, B, C, and D described in JIS K 0102:2016 Section 21, was added to purified water. Solution was made up to 1L. pH adjusted to 7.0.
- Solubilising agent (type and concentration if used): Not applicable
- Test temperature: 24.4 - 23.5°C 
- pH: 7.0
- pH adjusted: no
- Continuous darkness: yes
- suspended solids concentration: 30 mg/L

TEST SYSTEM
- Number of culture flasks/concentration: 3 flasks
- Method used to create aerobic conditions: Each test solution was stirred with a stirrer
- Measuring equipment: Closed system oxygen consumption measuring apparatus (No. CM-055)
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: not applicable

SAMPLING
- Sampling frequency: continuous
- Sterility check if applicable: yes
- Sample storage before analysis: not applicable
- Other: At end of study duration, pH and HPLC measurement were taken in the control, (test item + water) and toxicity control (test item + sludge)

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes

STATISTICAL METHODS:
Values were rounded off in accordance with JIS Z 8401:1999 rule B.

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Remarks:

Measured using HPLC

Value:

1

Sampling time:

28 d

Results with reference substance:

Aniline - Day 14 - 92% Degradation.
Validation criteria were met.

Table 1: Appearances and pH of the test solutions were as follows:

	Test solution	Appearance	pH
At Start of incubation	Water + test item	The test item was not dissolved. The test solution was colorless
	Sludge + test item	The test item was not dissolved. The test solution was colorless	-
	Control blank	Sludge observed. Test solution was colorless	-
At end of incubation	Water + test item	Insoluble compound was observed.  The test solution was colorless	Vessel No. 1: 7.2
	Sludge + test item	Insoluble compound in addition to sludge was observed.  Growth of the sludge was not observed. The test solution was colorless	Vessel No. 2: 7.4 Vessel No. 3: 7.4 Vessel No. 4: 7.4
	Control blank	Sludge observed. Test solution was colorless	Vessel No. 5: 7.5

 

Table 2: Analytical results of test solutions

		Water + test item	Sludge + test item			Theoretical amount
		Vessel No.1	Vessel No. 2	Vessel No. 3	Vessel No. 4
BOD1	mg	0.5	1.1	0.2	-0.8	58.2
Residual amount and percentage of test item (by HPLC)	mg	29.9	30.2	29.7	29.3	30.0
	%	100	101	99	98	-

₁The value of the test solution (control blank) was subtracted from the values of the test solutions (sludge + test item)

Table 3: % biodegradation on Day 28

		Sludge + test item
		Vessel No. 2	Vessel No. 3	Vessel No.4	Average
BOD	%	2	0	-1	0
Test item (by HPLC)	%	-1	1	2	1

Table 4: Validity of the test conditions

	Values in study		Criterion value
Difference between extremes of replicate values of % biodegradation in test olutions (sludge + test item) on Day 28	BOD	3%	<20%
	Test item (by HPLC)	3%
% biodegradation by BOD in test solution (sludge + aniline)	Day 7	75%	>40%
	Day 14	92%	>65%
BOD in test solution (control blank)	Day 28	35 mg/L*	<60 mg/L

*Measurement value (10.6mg/L)/[test volume (300mL) /1000] = 35 mg/L

Validity criteria fulfilled:

yes

Remarks:

see Table 4 in results section

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance is not readily biodegradable under the conditions of the study.

Description of key information

In a study conducted in accordance with OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I), 0% biodegradation was recorded after 28days (O2 consumption).The test substance is not readily biodegradable under the conditions of the study.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater