Reaction mass of 1-(3,3-dimethylcyclohex-1-en-1-yl)pent-4-en-1-one and 1-(5,5-dimethylcyclohex-1-en-1-yl)pent-4-en-1-one

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 9 October 2015 to 10 December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

Remarks:

Study is done according to Japanese guidelines which is equivalent to OECD TG 305

GLP compliance:

yes

Radiolabelling:

no

Details on sampling:

The test water of Level 1 and Level 2 were analyzed once before the first analysis of test fish and at the same time as analysis of test fish thereafter. One sample was analyzed at each sampling time.
Analysis of test fish was performed five times in test period. Four fish per treatment were taken out at each sampling time and divided into two groups (two fish per group) because one fish was not enough for the analytical sensitivity of the test item. Test fish analyses was carried out at intervals of more than 48 hours, and the final exposure period was 28 days. Analysis of control fish was performed before the experiment start and after the experiment completion. Four fish were taken out at the sampling time and divided into two groups, and analyzed individually.

Vehicle:

yes

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

PREPARATION OF STANDARD SOLUTION:
1) Test water
Test sample (100 mg) was accurately weighes with an electronic analytical balance and dissolved in hexane to obtain 1000 mg/L solution of the test item. The 0.4 mg/L solution of the test item was then prepared from this solution by dilution with hexane. This solution was pretreated to prepare 20 ug/L standard solution.

2) Fish
Test sample (100 mg) was accurately weighed with an electronical analytical balance and dissolved in hexane to obtain 1000 mg/L solution of test item. 1 mg/L solution of the test item was then prepared from this solution by dilution with hexane. This solution was pretreated to prepare 20 ug/L standard solution.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

SUPPLIER:
- CERI Kurume

CONDITIONS OF ACCLIMATIZATION:
The external disinfection was carried out in an aqueous solution containing OTC for fisheries (oxytetracycline hydrochloride, Kyoritsu Seikyaku) and sodium chloride (The Salt Industry Center of Japan). Thereafter fish were acclimatized in the following conditions:
Period: 52 days
Temperature: 25+/-2 ºC
Mortality during acclimatization was less than 5%.

- Length: 6.7 -8.3 cm
- Lot No.: TFC-150707
- Age: Yearling fish

FEEDING:
- Feed: Feed for colored carp
- Composition: Proteins content ≥ 30.0 %
- Lipid content: ≥ 4.0 %
- Manufacturer: Kyorin Food Corporation
- Feeding amount and interval: Amount corresponding to about 2 % of total body weight was fed once or twice a day in halves. The fish were starved for 24 hours before sampling.

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Test temperature:

Level 1 24.1-24.8ºC
Level 2 24.1-24.6ºC
Control 24.4-24.8ºC

pH:

Level 1 7.3, 7.3
Level 2 7.4, 7.3
Control 7.5, 7.5

Dissolved oxygen:

Level 1 6.7-7.1 mg/L
Level 2 6.8-7.1 mg/L
Control 7.4-7.6 mg/L

Details on test conditions:

TEST SYSTEM:
- Test vessel: 70-L glass tank for volatile item (Level 1 and 2); Control 70-L glass tank
- Flow rate of test water: 0.04 mL/min for stock solution and 2000 mL/min for dilution water, 2880 L/day of test water, were supplied.
-Stock solution bottle: 0.5-L glass brown bottle (Level 1 and 2); 3-L glass brown bottle (Control); Frequency of renewal: 1 time/week (Level 1 and 2), 1 time/month (Control)
- No. of organisms (at the beginning of exposure): 28 (Level 1 and 2)
- No. of organisms (control): 14

OTHER TEST CONDITIONS:
- Time of irradiation with light: Artificial light of white fluorescent lamp (14 hours/day)

Nominal and measured concentrations:

- Nominal:
Level 1: 10 µg/L
Level 2: 1 µg/L

- Measured:
Concentrations of test item were maintained >= 84% (Peak 1) and >= 86% (Peak 2) of nominal concentrations and the variations were within +/- 20% of the average measured concentrations.

Reference substance (positive control):

yes

Remarks:

pentachlorophenol sodium salt

Details on estimation of bioconcentration:

The bioconcentration factor was calculated at steady-state.

Lipid content:

3.43 %

Time point:

start of exposure

Lipid content:

3.68 %

Time point:

end of exposure

Key result

Conc. / dose:

10 µg/L

Temp.:

25 °C

pH:

7.7

Type:

BCF

Value:

117 L/kg

Basis:

whole body w.w.

Time of plateau:

7 d

Calculation basis:

steady state

Remarks on result:

other: corrected for 5% lipid

Remarks:

Based on the main constituent Peak 2

Conc. / dose:

10 µg/L

Temp.:

25 °C

pH:

7.7

Type:

BCF

Value:

86 L/kg

Basis:

whole body w.w.

Time of plateau:

7 d

Calculation basis:

steady state

Remarks on result:

other: Peak 2

Remarks:

Main constituent, Conc.in environment / dose:0.899 µg/l

Conc. / dose:

1 µg/L

Temp.:

25 °C

pH:

7.7

Type:

BCF

Value:

16 L/kg

Basis:

whole body w.w.

Time of plateau:

7 d

Calculation basis:

steady state

Remarks on result:

other: Peak 1

Remarks:

Conc.in environment / dose:9.46 µg/l

Conc. / dose:

10 µg/L

Temp.:

25 °C

pH:

7.7

Type:

BCF

Value:

83 L/kg

Basis:

whole body w.w.

Time of plateau:

7 d

Calculation basis:

steady state

Remarks on result:

other: Peak 2

Remarks:

Conc.in environment / dose:9.95 µg/l

Details on results:

Each concentration of the test item was maintained at more than 84 % (Peak 1) and more than 86% (Peak 2) of nominal concentrations. The variation of the concentrations of the test item was within ± 20 % of the average of the measured concentrations.

Results of test fish observation:

No abnormality in behavior or appearance was noted.

BCF at steady state

 The variation of BCFs:

Peak	Level		After 21 days	After 24 days	After 28 days	Average of 3 results
1 Minor constituent: 3,3 Galbascone	1 (10 ug/l)	Average BCF	18.035	13.760	15.262	15.686
		Variation rate from average of 3 results (%)	14.975	12.273	2.7017
	2 (1 ug/l)	Average BCF	91.257	77.258	78.224	82.246
		Variation rate from average of 3 results (%)	10.955	6.0654	4.8905
2 Major constituent: 5,5 Galbascone	2 (10 ug/l)	Average BCF	83.850	79.160	90.009	84.340
		Variation rate from average of 3 results (%)	0.58110	6.1410	6.7221

Peak 2 is the main constituent (5,5 Galbascone) and could be determined at both the 10 and 1 ug/l. Peak 1 could only de determined at the 10 ug/l level. The BCFs steady states are within the +/- 20% of the average for these days' BCFs and thererfore acceptable: after 21, 24 and 28 days from the initiation of exposure were 3 -15% (peak 1 in Level 1), 5 -11% (Peak 2 in Level 1) and 1 -7% (Peak 2 in Level 2)

Validity criteria fulfilled:

yes

Remarks:

Water concentrations were maintained, BCF duplicates were within the 20% variability range as was the lipid content at the start and finish.

Conclusions:

The steady-state BCF value in Japanese carp (Cyprinus carpio) using the main constituent (5,5-Galbascone) and corrected for 5% lipid content is 117 L/kg.

Executive summary:

A study on the bioaccumulation potential of the substance was performed equivalent to OECD TG 305 and GLP. In this study, whole-body steady-state bioconcentration factors (BCF) for Japanese carp (Cyprinus carpio) were examined at test concentrations of 1 µg/L and 10 µg/L in a flow-through system at 25oC. Each concentration of the test item in water was maintained at more than 84 % of each nominal concentration. The variation of the concentrations of the test item in fish was within ± 20 % of the average of the measured concentrations. Steady-state was reached within 7 days. At 1 and 10 ug/l the BCF for the main constituent is 86 l/kg. At 10 ug/l the BCF for the minor constituent is 16 l/kg, at 1 ug/l the BCF of the minor constituent was below the limit of detection in fish. The lipid content in the fish at the end of the test was 3.68% (and 3.43 at the start) and therefore the BCFss were normalized to 5% lipid content using the highest BCF value for the main constituent. This results in a BCF of 117 l/kg.

Description of key information

A study on the bioaccumulation potential of the substance was performed equivalent to OECD TG 305 and GLP. In this study, whole-body steady-state bioconcentration factors (BCF) for Japanese carp (Cyprinus carpio) were examined at test concentrations of 1 µg/L and 10 µg/L in a flow-through system at 25oC. Each concentration of the test item in water was maintained at more than 84 % of each nominal concentration. The variation of the concentrations of the test item in fish was within ± 20 % of the average of the measured concentrations. Steady-state was reached within 7 days. At 1 and 10 ug/l the BCF for the main constituent is 86 l/kg. At 10 ug/l the BCF for the minor constituent is 16 l/kg, at 1 ug/l the BCF of the minor constituent was below the limit of detection in fish. The lipid content in the fish at the end of the test was 3.68% (and 3.43 at the start) and therefore the BCFss were normalized to 5% lipid content using the highest BCF value for the main constituent. This results in a BCF of 117 l/kg.

Key value for chemical safety assessment

BCF (aquatic species):

117 L/kg ww