1,4-bis(methoxymethyl)benzene

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:

From 2011-01-17 to 2011-02-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: "Biodegradation test of a chemical substance using a microorganism etc." provided in "the Notice on the Test Method Concerning New Chemical Substances"

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 99.8%

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

- Preparation:
a) Determination of concentrations of suspended substances in activated sludge
Concentrations of suspended substances were determined to set the amount of activated sludge to be added.
Determination method: according to 14.1 of JIS K 0102-2010
Findings: The concentration of substances suspended in activated sludge was 3,920 mg/mL.
b) Preparation of basic culture media:
Purified water was added to 3 mL each of Fluids A, B, C and D of the composition specified in 21 in JIS K 0102-1993 to make 1 L (total volume prepared: 5 L), and the pH value of the mixture obtained was adjusted to 7.0.
c) Confirmation of efficacy of activated sludge:
It was confirmed using aniline that activated sledge has sufficient activity.

- Preparation of test solutions:
Six test vessels were prepared and test solutions were prepared as mentioned below.
a) Addition of the test substance or aniline:
1) (Water + test substance) system (1; Vessel 1): Purified water (300 mL) and sample (30 mg) were added to a test vessel so that the concentration of the test substance was 100 mg/L. The sample was accurately measured using an electronic balance before addition and pH was measured.
2) (Sludge + test substance) system (3; Vessels 2, 3 and 4): Basic culture medium (300 mL - volume (2.30 mL) of activated sludge added) and sample (30 mg) were introduced into test vessels so that the concentration of the test substance was 100 mg/L. The sample was accurately weighed using an electronic balance before addition and pH was measured after addition.
3) (Sludge + aniline) system (1; Vessel 6): Basic culture medium (300 mL - volume (2.30 mL) of activated sludge added) and aniline (29.5 μL; 30 mg) were introduced into the test vessel so that the concentration of aniline was 100 mg/L. Aniline was pipetted using a micro syringe and added.
4) Sludge blank system (1; Vessel 5): Basic culture medium (300 mL - volume (2.30 mL) of activated sludge added) was introduced into the test vessel.
b) Inoculation of activated sludge:
Activated sludge was added to the test solutions prepared in 2), 3) and 4) above so that the concentration of suspended substances was 30 mg/L.

- Test solution cultivation system and cultivation conditions:
a) Test solution cultivation system:
Closed oxygen demand measuring system: Thermostat (including measuring unit): OM3100A
Data processor: DS-3 (Asahi Techneion Co., Ltd.)
Test vessel: culture bottle for 300 mL (modified culture bottle)
Carbon dioxide adsorbent: soda lime No. 1 (Wako Pure Chemical Industries, Ltd.; for absorption of carbon dioxide)
b) Cultivation conditions:
Temperature: 25±1°C
Period: 28 days (protected from light)
Stirring method: stirring by rotation using a stirrer

- Observation, determination, etc.
a) Observation: During the cultivation period, test solutions were observed everyday with the naked eye.
b) Determination of biochemical oxygen demand (BOD): During the cultivation period, changes in BOD in test solutions were continuously monitored using the closed oxygen demand measuring system. In addition, temperature of the thermostat in the closed oxygen demand measuring system was recorded every day.

- Analysis of test solutions: After the cultivation period, dissolved organic carbon (DOC) and the test substance in test solutions were analyzed. pH of test solutions from the (water + test substance) and (sludge + test substance) systems was determined.

Reference substance:

aniline

Test performance:

This study was judged to be valid because all values found are within the reference range.

Key result

Parameter:

% degradation (O2 consumption)

Value:

3

Sampling time:

28 d

Key result

Parameter:

% degradation (DOC removal)

Value:

5

Sampling time:

28 d

Key result

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Status of test solutions:

	Test solution	Status	pH
Before starting culture	(water + test substance) system	The test substance dissolved.	[1] 6.9
	(sludge + test substance) system	The test substance dissolved.	[2] 7.0 [3] 7.0 [4] 7.0
Upon completion of culture	(water + test substance) system	No insoluble matter was found.	[1] 7.1
	(sludge + test substance) system	No insoluble matter other than sludge was found. Sludge showed no growth.	[2] 7.3 [3] 7.3 [4] 7.4

Results of analysis of test solutions:

The results of analysis conducted 28 days later are shown below.

		(water + test substance) system	(sludge + test substance) system			Theoretical value
		[1]	[2]	[3]	[4]
BOD^*2	mg	1.4	1.3	2.4	2.2	72.3
^*2 Amount and rate of residual DOC	mgC	20.6	19.5	19.7	19.7	20.3^*3
	%	101	96	97	97	-
Amount and rate of residual test substance (HPLC)	mg	29.1	29.3	29.3	29.4	30.0
	%	97	98	98	98	-

*2  Values obtained from the sludge blank system was subtracted in the case of the (sludge + test substance) system.

*3  Calculated from the mean DOC concentration found from the 20.0 mg/L test substance solution (n=3).

Degradations (%):

Degradations (%) determined 28 days later are as shown below.

		(Sludge + test substance) system
		[2]	[3]	[4]	Mean
BOD degradation	%	2	3	3	3
DOC degradation	%	5	4	4	5
Test substance degradation (HPLC)	%	-1	-1	-1	0 (-1)^*1

*1  Because the mean % degradation obtained by calculation was a negative figure, the mean was reported to be zero (0) and the value obtained by calculation was reported in parentheses.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The mean % BOD degradation, % DOC degradation and % degradation of the test substance were 3%, 5% and 0%, respectively. In addition, the test substance showed no significant change on HPLC chromatograms obtained in its quantitative analysis, indicating that the test substance escaped biodegradation under the conditions of the present study.

Executive summary:

The biodegradation test of test substance was performed using a microorganism. Six test vessels were prepared and the concentration of the test substance was 100 mg/L, the concentration of active sludge was 30 mg/L (concentration of suspended substances). The test solutions were cultivated at 25±1°C for28 days (protected from light).

The mean % BOD degradation, % DOC degradation and % degradation of the test substance were 3%, 5% and 0%, respectively. In addition, the test substance showed no significant change on HPLC chromatograms obtained in its quantitative analysis, indicating that the test substance escaped biodegradation under the conditions of the present study.

Description of key information

The biodegradation test of test substance was performed using a microorganism.

The mean % BOD degradation, % DOC degradation and % degradation of the test substance were 3%, 5% and 0%, respectively. In addition, the test substance showed no significant change on HPLC chromatograms obtained in its quantitative analysis, indicating that the test substance escaped biodegradation under the conditions of the present study.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The biodegradation test of test substance was performed using a microorganism. Six test vessels were prepared and the concentration of the test substance was 100 mg/L, the concentration of active sludge was 30 mg/L (concentration of suspended substances). The test solutions were cultivated at 25±1°C for28 days (protected from light).

The mean % BOD degradation, % DOC degradation and % degradation of the test substance were 3%, 5% and 0%, respectively. In addition, the test substance showed no significant change on HPLC chromatograms obtained in its quantitative analysis, indicating that the test substance escaped biodegradation under the conditions of the present study.