2,4,8,10-tetra(tert-butyl)-6-hydoroxy-12H-dibenzo[d,g] [1,3,2]dioxaphosphocin, 6-oxide

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 2017-11-22 to 2017-12-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -I: Aqueous Exposure Bioconcentration Fish Test

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Purity: > 99%
Batch No.: 101Z4

Radiolabelling:

no

Details on sampling:

Sampling frequency
- Test fish analysis:
The test fish of Levels 1 and 2 were analyzed five times during uptake phase. The test fish for Control was analyzed only at the end of uptake phase.
- Test water analysis:
The test water of Levels 1 and 2 were analyzed once before uptake phase and at the same time as analysis of test fish. The test water for Control was analyzed only at the end of uptake phase.

Details on sampling and analysis of test samples
- Test water analysis:
Level 1: the 10 mL of test water was taken from the test tank with graduated cylinder and pretreated for LC-MS/MS analysis
Level 2 and Control: An aliquot of test water were taken from each test tank and pretreated for LC-MS/MS analysis
- Test fish analysis: Test fish (four fish per treatment level) were taken from each test tank and pretreated for LC-MS/MS analysis

Vehicle:

yes

Remarks:

N,N-Dimethylformamide

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

Acute toxicty test:
The test sample (200 mg) and HCO-40 (2.0 g) were dissolved in N,N-dimethylformamide to prepare 10.0 g/L stock solution (20 mL). This stock solution was diluted appropriately with the dilution water to prepare the test solution.
Bioconcentration test:
- Level 1: The test sample (1000 mg) and HCO-40 (10 g) were dissolved in N,N-dimethylformamide to prepare 2000 mg/Lstock solution of the test item (0.5 L).
- Level 2: The test sample (1000 mg) and HCO-40 (10 g) were dissolved in N,N-dimethylformamide to prepare 200 mg/Lstock solution of the test item (0.5 L).
- Control: HCO-40 (40 g) were dissolved in N,N-dimethylformamide to prepare 20 g/L stock solution of HCO-40 (2 L).

Test organisms (species):

other: Cyprinus carpio in bioconcentration test , Oryzias latipes in acute toxicity test

Details on test organisms:

Cyprinus carpio
- Source: CERI Kurume
- Age: one-year-old
- Length: 7.0-8.8 cm (at the beginning of uptake phase 7.3-8.0 cm)
- Feeding during test
- Feed: feed for colored carp
- Composition: proteins content >=30% lipid content >=4.0%
- Amount and interval: Amount corresponding to 2% of total body weight was fed. The daily dose of feed was split into two feedings (once a day on holiday). The fish were starved for 24 hours before the sampling.

- Conditions for acclimatization
- Acclimation period: 81 days
- Temperature: 25 ± 2 °C
- Health during acclimation (any mortality observed): Mortality during acclimatization was less than 5%.

Oryzias latipes
- Source: Kitamura fish farm
- Length: 2.8-3.0 cm
- Weight: 0.20-0.23 g

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

Level1: 18.1 mgCaCO3/L
Control: 18.1 mgCaCO3/L

Test temperature:

Before uptake phase
- Level 1: 24.6-24.8 °C
- Level 2: 24.5-24.6 °C
- Control: 25.0 °C
During uptake phase
- Level 1: 24.5-25.0 °C
- Level 2: 24.3-24.7 °C
- Control: 24.7-25.1 °C

pH:

Before uptake phase
- Level 1: 7.5
- Level 2: 7.5
- Control: 7.5
During uptake phase (at the beginning and end of uptake phase)
- Level 1: 7.5, 7.6
- Level 2: 7.5, 7.6
- Control: 7.5, 7.6

Dissolved oxygen:

Before uptake phase
- Level 1: 7.9 mg/L
- Level 2: 7.9 mg/L
- Control: 7.9 mg/L
During uptake phase
- Level 1: 7.7-7.9 mg/L
- Level 2: 7.7-7.9 mg/L
- Control: 7.7-7.9 mg/L

TOC:

Before uptake phase (before 48 h and 24 h)
- Level 1: 23.1, 23.7 mgC/L
- Level 2: 23.3, 23.4 mgC/L
- Control: 22.3, 22.0 mgC/L
During uptake phase
- Level 1: 21.9-24.0 mgC/L
- Level 2: 20.9-23.9 mgC/L
- Control: 20.4-22.7 mgC/L

Details on test conditions:

TEST SYSTEM
- Test tank: 70-L glass tank
- Aeration: supplied with air during uptake phase
- Renewal rate of test solution (frequency/flow rate): levels 1 and 2: once / week, control: twice / month; 0.04 mL/min for stock solution and 800 mL/min for dilution water, 1152 L/day of test water
- Number of fish (at the beginniing of uptake phase): Levels 1 and 2 : 26 fish, Control: 16 fish

TEST MEDIUM / WATER PARAMETERS
- Source of dilution water: Groundwater from the premises of CERI Kurume

OTHER TEST CONDITIONS
- Photoperiod: 14 hours light / 10 hours dark (artifical of white fluorescent lamp)

RANGE-FINDING / PRELIMINARY STUDY
- Test concentrations: 10 mg/L and control
- Results used to determine the conditions for the definitive study: 96-hour LC50 value of the test item > 10.0 mg/L. No diseases were observed in control.

Nominal and measured concentrations:

Nominal
Level 1: 100 μg/L
Level 2: 10 μg/L

Reference substance (positive control):

no

Lipid content:

5.66 %

Time point:

start of exposure

Lipid content:

5.47 %

Time point:

end of exposure

Key result

Conc. / dose:

100 µg/L

Type:

BCF

Value:

3.9 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Key result

Conc. / dose:

10 µg/L

Type:

BCF

Value:

< 15 L/kg

Basis:

whole body w.w.

Details on results:

- Results of test fish observation: No abnormaliity in behavior or appearance was noted.
- Concentration of test item in test water: Concentrations of the test item in test water were 103 μg/L (Level 1) and 9.91 μg/L (Level 2) before uptake phase, 96.0 μg/L (Level 1) and 9.82 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control water before or after uptake phase.
- Concentration of test item in test fish: Concentrations of the test item in test fish were 258, 358 μg/L (Level 1) and less than 140 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control fish after uptake phase.
- BCFs at steady-state (BCFss):
Level 1: 3.9 L/kg
Level 2: Because the test item in all test fish at four successive analyses after 13, 23, 26 and 28 days from the initiation of uptake were not more than the LOQ, BCFss could not be calculated.
- Growth rate constant (kg): Level 1: 0.00851 /day, Level 2: 0.0101 /day, Control: 0.00766 /day

Validity criteria fulfilled:

yes

Conclusions:

The BCFs at a steady - state was 3.9 L/kg (Level 1), the BCFs in level 2 was less than 15 L/kg.

Executive summary:

The study was aimed at evaluating the bioconcentration potential of the test item in commom carp according to OECD Guideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -I: Aqueous Exposure Bioconcentration Fish Test.

A solution with a standard concentration of 100 μg/L (level 1), 10 μg/L (level 2) were prepared, the test fish were exposed

to two different test solutions. A blank control group was set simultaneously. The contentration of the test item in the test fish and test water were measured regularly. Analyses of the test item in the test fish and test water were performed with Liquid chromatography-tandem masss spectrometry.

No abnormaliity in behavior or appearance by observation was noted. The growth rate constant was 0.00851 kg/day (Level 1), 0.0101 kg/day (Level 2), 0.00766 kg/day (Control). Lipid content in test fish were 5.66% before inititation of experiment, 5.47% after termination of experiment. Concentrations of the test item in test water were 103 μg/L (Level 1) and 9.91 μg/L (Level 2) before uptake phase, 96.0 μg/L (Level 1) and 9.82 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control water before or after uptake phase. Concentrations of the test item in test fish were 258, 358 μg/L (Level 1) and less than 140 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control fish after uptake phase. The BCFs at steady-state (BCFss) was 3.9 L/kg (Level 1). The BCFs in level 2 was less than 15 L/kg. Because the test item in all test fish at four successive analyses after 13, 23, 26 and 28 days from the initiation of uptake were not more than the LOQ, BCFss could not be calculated. However, because all BCFs were less than 100 L/kg, it was evaluated that a steady-state was reached after 28 days.

The BCFs at a steady - state was 3.9 L/kg (Level 1), the BCFs in level 2 was less than 15 L/kg.

Description of key information

The BCFs at a steady - state was 3.9 L/kg (Level 1: 100 μg/L), the BCFs in level 2 (10 μg/L) was less than 15 L/kg.

Key value for chemical safety assessment

BCF (aquatic species):

15 L/kg ww

Additional information

The study was aimed at evaluating the bioconcentration potential of the test item in commom carp according to OECDGuideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -I: Aqueous Exposure Bioconcentration Fish Test.

A solution with a standardconcentration of 100 μg/L (level 1), 10 μg/L (level 2) were prepared, the test fish were exposed

to two different test solutions. A blank control group was set simultaneously. The contentration of the test item in the test fish and test water were measured regularly. Analyses of the test item in the test fish and test water were performed with Liquid chromatography-tandem masss spectrometry.

No abnormaliity in behavior or appearance by observation was noted. The growth rate constant was 0.00851 kg/day (Level 1), 0.0101 kg/day (Level 2), 0.00766 kg/day (Control). Lipid content in test fish were 5.66% before inititation of experiment, 5.47% after termination of experiment. Concentrations of the test item in test water were 103 μg/L (Level 1) and 9.91 μg/L (Level 2) before uptake phase, 96.0 μg/L (Level 1) and 9.82 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control water before or after uptake phase. Concentrations of the test item in test fish were 258, 358 μg/L (Level 1) and less than 140 μg/L (Level 2) after 28 days. No interfering peak was observed at the peak positions of the test item in the LC-MS/MS chromatogram for the control fish after uptake phase. The BCFs at steady-state (BCFss) was 3.9 L/kg (Level 1). The BCFs in level 2 was less than 15 L/kg. Because the test item in all test fish at four successive analyses after 13, 23, 26 and 28 days from the initiation of uptake were not more than the LOQ, BCFss could not be calculated. However, because all BCFs were less than 100 L/kg, it was evaluated that a steady-state was reached after 28 days.

The BCFs at a steady - state was 3.9 L/kg (Level 1: 100 μg/L), the BCFs in level 2 (10 μg/L) was less than 15 L/kg.