Reaction products of 2,4-bis(2-chlorophenyl)-5-(3,4-dimethoxy phenyl)-1H-imidazole and 2-(2-chlorophenyl)-4,5-diphenyl-1H-imidazole

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: “Testing method for new chemical substances” (Bioconcentration test of chemical substances in the bodies of fish and shellfish) prescribed in (Environmental Protection Services, No. 5, Drug No. 615, 49 Base Station, No. 392, July 13, 1974, revised on Octo

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 (Bioconcentration: Flow-through Fish Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Details on test material:

- Purity: 100 wt% as a reaction product

Radiolabelling:

no

Sampling and analysis

Details on sampling:

Uptake Phase Sampling Days: 8, 10, 14, 22 and 28
Number of Water Samples: 1 sample per test concentration per sampling day
Number of Fish Samples: 4 fish per test concentration per sampling day. Fish were divided into 2 groups.

Test solutions

Vehicle:

yes

Details on preparation of test solutions, spiked fish food or sediment:

Stock Solutions
Two stock solutions (80 mg/L and 800 mg/L) were prepared by adding the appropriate amounts of test substance and HCO-40 at 20 times its amount in acetone. The acetone was distilled off and the stock solutions brought to final volume with ion-exchange water. The operation was carried out under light-shielded conditions.

Test Solutions
Based on the 96-h LC50 preliminary value (Oryzias latipes, 96-h LC50 was > 250 mg/L) and the sensitivity of the analytical method, the test substance concentration was set to 2 mg/L and 0.2 mg/L. The control group was prepared by dissolving HCO-40 in ion-exchange water.

Test organisms

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Carp, Cyprinus carpio
Supply source: Yabekawa Fishery Union of Fukuoka-ken

Upon receipt, abnormal fish were removed, and the remaining fish were maintained in a flow-through system at a water temperature of 25 ± 2°C for up to 53 days.

Total length: 6.8-8.6 cm

Feed: Mixed feed for carp fry growth
Composition: Protein content 43.0% or more, Lipid content 3.0% or more
Manufacturer: Nippon Formula Feed Mfg. Co., Ltd.
Feeding method: An amount corresponding to about 2% of the total fish weight was divided and fed to each test group twice a day during the study. Feeding was stopped for 24 h before sampling of the fish.

Study design

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Test conditions

Hardness:

106 mg/L

Test temperature:

25.0-25.7°C

pH:

7.8-7.9

Dissolved oxygen:

7.7-8.1 mg/L

TOC:

0.9 mg/L

Details on test conditions:

TEST AND ENVIRONMENTAL CONDITIONS
- Test water supply method: The test water was supplied by using an assembled flow-through type apparatus of the Kurume Laboratory.
- Test water tank: 100 L glass tank
- Amount of test water: 1,155 L/day was supplied at a ratio of 2 mL/min stock solution and 800 mL/min water was supplied to the test water tank.
- Stock solution tank: 25 L glass bottles (under a light-shielded condition)
- Illumination time: Artificial illumination by white fluorescent lamp (bright for 14 h/dark for 10 h)
- Number of provided fish: First and second concentration levels 28 fish (at time of exposure start)
- Control group 10 fish (at time of exposure start)
- Exposure period: 28 days
- Biomass loading rate: not reported

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Kurume laboratory
- Particulate matter: <1 mg/L
- Metals:<0.02 mg/L
- Pesticides:<0.001 mg/L
- Chlorine:<0.01 mg/L
- Alkalinity:92.7 mg/L
- Ca/mg ratio:106 mg/L
- Conductance:379 µs/cm

Nominal and measured concentrations:

Nominal concentrations: 2 mg/L (1st level) and 0.2 mg/L (2nd level)

Details on estimation of bioconcentration:

The methods used for calculating the bioconcentration factor, bioconcentration factor in a stationary state (BCFss), and lipid content followed those outlined in the OECD guidelines.

There were no corresponding Environmental factors considered to have an influence on the reliability of test records.

Results and discussion

Lipid content

Lipid content 1

Lipid content:

2.34 %

Time point:

other: Total Average

Lipid content 2

Lipid content:

1.43 %

Time point:

end of exposure

Lipid content 3

Lipid content:

2.25 %

Time point:

start of exposure

Bioaccumulation factor

Bioaccumulation factor 1

Type:

BCF

Value:

45

Basis:

other: Peak 1

Calculation basis:

steady state

Remarks on result:

other: The test substances is a reaction product with several isomers. Peak 1: 45 times, Peak 2: 1.5 times, Peak 3: 3.5 times, Peak 4: 1.6 times, Peak 5: 1.4 times, Peak 6: 4.4 times

Remarks:

Conc.in environment / dose:2 mg/L

Bioaccumulation factor 2

Type:

BCF

Value:

140

Basis:

other: Peak 1

Calculation basis:

steady state

Remarks on result:

other: The test substances is a reaction product with several isomers. Peak 1: 140 times, Peak 2: 9.8 times, Peak 3: 17 times, Peak 4: 20 times, Peak 5: 8.8 times, Peak 6: 21 times

Remarks:

Conc.in environment / dose:0.2 mg/L

Bioaccumulation factor 3

Type:

BCF

Value:

140

Basis:

other: Peak 1

Calculation basis:

other: stationary state per average lipid content

Remarks on result:

other: Peak 1: 140 times

Remarks:

Conc.in environment / dose:0.2 mg/L

Details on kinetic parameters:

- Uptake rate constant (k1): not reported
- Depuration (loss) rate constant (k2): not reported
- Indication of bi- or multiphasic kinetics: not reported

Metabolites:

Not reported

Details on results:

Test results:
Bioconcentration Factor in a Stationary State:
Peak 1: 2 mg/L concentration level, 45 times; 0.2 mg/L concentration level, 140 times
Peak 2: 2 mg/L concentration level, 1.5 times; 0.2 mg/L concentration level, 9.8 times or less
Peak 3: 2 mg/L concentration level, 3.5 times; 0.2 mg/L concentration level, 17 times or less
Peak 4: 2 mg/L concentration level, 1.6 times; 0.2 mg/L concentration level, 20 times
Peak 5: 2 mg/L concentration level, 1.4 times; 0.2 mg/L concentration level, 8.8 times
Peak 6: 2 mg/L concentration level, 4.4 times; 0.2 mg/L concentration level, 21 times


Bioconcentration Factor in a Stationary State based on Average Lipid Content
Peak 1: 0.2 mg/L concentration level, 140 times


Regarding the Test Substance Concentration in Test Water of Peak 1:
As a result of the preliminary review, it was confirmed that the test substance was visually changed and the component of the peak 1 was increased. In this test, it is considered that since part of the test substance provided into the water tank is also visually changed, the test substance concentration in the test water of the peak 1 is largely raised.

Regarding the Lipid Content:
The change of the lipid content exceeded 25% after the experiment end, compared with that before the experiment start. Because the test fish are carp fry, the control of the lipid content is very difficult, and the individual difference are variable, the lipid content in this test is changed.

Any other information on results incl. tables

Table 1. BIOCONCENTRATION FACTOR IN THE STATIONARY STATE

Peak	2 mg/L	0.2 mg/L
1	45 times	140 times
2	1.5 times	9.8 times or less
3	3.5 times	17 times or less
4	1.6 times	20 times
5	1.4 times	8.8 times
6	4.4 times	21 times
1		140 times (per average lipid content)

At 0.2 mg/L the bioconcentration factor (average) corrected by the average lipid content, the change with respect to the average value of the bioconcentration factor in its 3-time analysis was within 20%, it was decided that the bioconcentration factor reached a stationary state. Using these results, the bioconcentration factor in a stationary state was calculated. Also, for comparison, the value for the case where the liquid correction was not made was calculated.

At 2.0 mg/L bioconcentration factor (average) after 14, 22, and 28 days was less than 100 times, however since the change with the respect to the average value of the bioconcentration factor in its 3-time analysis was within 20%, it was decided that the bioconcentration factor reached a stationary state. Using these results, the bioconcentration factor in a stationary state was calculated.

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Table 2: BIOCONCENTRATION FACTOR CORRECTED BY THE AVERAGE LIPID CONTENT

Peak	Concentration	After 14 days	After 22 days	After 28 days
1	0.2 mg/L	120	190	130
		140	140	140
		130 (avg.)	170 (avg.)	140 (avg.)

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TEST SUBSTANCE CONCENTRATION IN TEST WATER

In the test substance concentration in the test water, Table 3, 79% or more of the set values was held. Also, the change of the testing substance concentration was held within ± 20% with respect to the average of the measured values except for the first concentration level of the peak 1.

 

Table 3. TEST SUBSTANCE CONCENTRATION IN TEST WATER (mg/L)

Peak	Concentration	After 1 Day	After 8 Days	After 10 Days	After 14 Days	After 22 Days	After 28 Days	Average	Standard Deviation
1	2 mg/L	7.25	6.91	7	6.06	10.7	6.85	7.47	1.647
1	0.2 mg/L	1.83	1.61	1.47	1.61	1.76	1.4	1.61	0.163
2	2 mg/L	1.97	1.88	1.79	1.83	1.95	2.01	1.9	0.087
2	0.2 mg/L	0.158	0.178	0.174	0.185	0.179	0.18	0.176	0.0094
3	2 mg/L	2.11	2.46	1.95	2.04	2.45	2.22	2.21	0.214
3	0.2 mg/L	0.215	0.269	0.212	0.233	0.254	0.218	0.233	0.0233
4	2 mg/L	1.87	1.89	1.68	1.7	1.88	1.84	1.81	0.094
4	0.2 mg/L	0.164	0.184	0.166	0.174	0.173	0.166	0.171	0.0074
5	2 mg/L	1.85	1.77	1.67	1.7	1.99	1.82	1.8	0.116
5	0.2 mg/L	0.168	0.176	0.172	0.177	0.186	0.171	0.175	0.0062
6	2 mg/L	2.12	2.03	1.98	1.97	2.28	2.15	2.09	0.119
6	0.2 mg/L	0.209	0.218	0.22	0.224	0.236	0.219	0.221	0.0088

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Table 4. BIOCONCENTRATION FACTOR IN CARP FRY

		After 8 days			After 10 days			After 14 days			After 22 days			After 28 days
Peak	Concentration	Fish 1	Fish 2	Avg.	Fish 1	Fish 2	Avg.	Fish 1	Fish 2	Avg.	Fish 1	Fish 2	Avg.	Fish 1	Fish 2	Avg.
1	2 mg/L	71	58	65	66	47	56	38	40	39	66	60	63	39	50	45
1	0.2 mg/L	150	140	140	93	80	86	94	110	100	200	160	180	140	160	150
2	2 mg/L	0.90 or less	0.90 or less	0.90 or less	0.90 or less	0.90 or less	0.90 or less	1.5	1.2	1.4	1.7	1.9	1.8	2	1.2	1.6
2	0.2 mg/L	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less	9.8 or less
3	2 mg/L	1.8 or less	1.8 or less	1.8 or less	1.8 or less	1.8 or less	1.8 or less	3.1	2.6	2.8	3.3	4.5	3.9	4.2	3.7	3.9
3	0.2 mg/L	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less	17 or less
4	2 mg/L	0.81	0.78	0.8	0.78	0.7	0.74	1.2	0.8	0.98	1.2	2	1.6	1.9	1.3	1.6
4	0.2 mg/L	6.7	6.5	6.6	5.5	4.8	5.2	6.9	9.1	8	15	19	17	27	13	20
5	2 mg/L	0.82	0.77	0.8	0.94	0.87	0.91	1.5	1.2	1.3	1.2	1.7	1.5	1.7	1.1	1.4
5	0.2 mg/L	7.1	7.3	7.2	7.1	6.9	6.5	8.6	11	9.8	9.2	7.9	8.6	8	8.3	8.1
6	2 mg/L	1.7	2.3	2	1.7	1.6	1.7	2.8	3	2.9	3.1	3.9	3.5	4.9	3.9	4.4
6	0.2 mg/L	18	14	16	8.7	7.6	8.1	11	15	13	17	13	15	19	22	21

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Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Bioconcentration Factor in a Stationary State:
Peak 1: 2 mg/L concentration level, 45 times; 0.2 mg/L concentration level, 140 times
Peak 2: 2 mg/L concentration level, 1.5 times; 0.2 mg/L concentration level, 9.8 times or less
Peak 3: 2 mg/L concentration level, 3.5 times; 0.2 mg/L concentration level, 17 times or less
Peak 4: 2 mg/L concentration level, 1.6 times; 0.2 mg/L concentration level, 20 times
Peak 5: 2 mg/L concentration level, 1.4 times; 0.2 mg/L concentration level, 8.8 times
Peak 6: 2 mg/L concentration level, 4.4 times; 0.2 mg/L concentration level, 21 times

Bioconcentration Factor in a Stationary State Based on Average Lipid Content
Peak 1: 0.2 mg/L concentration level, 140 times

Executive summary:

Bioconcentration test, OECD 305

(1) Test fish: Carp

(2) Test concentration: First concentration level 2 mg/L, Second concentration level 0.2 mg/L

(3) Exposure period: 28 days

(4) Exposure method: Continuous water flow type

(5) Analysis method: HPLC

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Test results:

Bioconcentration Factor in a Stationary State:

Peak 1: 2 mg/L concentration level, 45 times; 0.2 mg/L concentration level, 140 times

Peak 2: 2 mg/L concentration level, 1.5 times; 0.2 mg/L concentration level, 9.8 times or less

Peak 3: 2 mg/L concentration level, 3.5 times; 0.2 mg/L concentration level, 17 times or less

Peak 4: 2 mg/L concentration level, 1.6 times; 0.2 mg/L concentration level, 20 times

Peak 5: 2 mg/L concentration level, 1.4 times; 0.2 mg/L concentration level, 8.8 times

Peak 6: 2 mg/L concentration level, 4.4 times; 0.2 mg/L concentration level, 21 times

-

Bioconcentration Factor in a Stationary State Based on Average Lipid Content

Peak 1: 0.2 mg/L concentration level, 140 times

-

Regarding the Test Substance Concentration in Test Water of Peak 1: As a result of the preliminary review, it was confirmed that the test substance was visually changed and the component of the peak 1 was increased. In this test, it is considered that since part of the test substance provided into the water tank is also visually changed, the test substance concentration in the test water of the peak 1 is largely raised. - Regarding the Lipid Content: The change of the lipid content exceeded 25% after the experiment end, compared with that before the experiment start. Because the test fish are carp fry, the control of the lipid content is very difficult, and the individual difference are variable, the lipid content in this test is changed