Phosphoric acid, mixed esters with biphenyl-4,4'-diol and phenol

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Testing Methods for New Chemical Substances (Nov 21, 2003, No.1121002, Pharmaceutical and Food Safety Bureau, MHLW; Nov 13, 2003 No.2, Manufacturing Industries Bureau, METI; No.031121002, Environmental Policy Bureau, Ministry of the Environment)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

(1996)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Details on sampling:

- Sampling intervals/frequency for test organisms: test fish of Level 1 and 2 were analysed on Day 3, 9, 15, 22 and 28, control fish at start and end of exposure.
- Sampling intervals/frequency for test medium samples: Day 1, 3, 9, 15, 22 and 28
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):
test organisms: homogenized with acetonitrile, centrifugation, filtration of supernatant, HPLC analysis
test media samples: 1:2 in acetonitrile (Level 1-samples were diluted 1:10 with water before), HPLC analysis

Vehicle:

yes

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

PREPARATION OF SPIKED WATER/TEST SOLUTIONS
- Details of spiking:
Stock solutions of the test material were prepared with the aid of HCO-40 (hydrogenated castor oil, dispersant) and DMSO (dimethylsulfoxide, organic solvent)
Level 1: A 400 mg/L stock solution was prepared by dissolving test material and HCO-40 (10 times the amount of test material) in DMSO.
Level 2: A 40 mg/L stock solution was prepared from the stock solution for Level 1 by dilution with DMSO.
- Control: HCO-40 was dissolved in DMSO to prepare a stock solution of 4 g/L
- Concentration of vehicle in final test solution:
HCO-40: 0.2 µL/L for Level 1 and control, 0.02 µL/L for Level 2
DMSO: 50 µL for Level 1, 2 and control

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: carp
- Source: Kurume Laboratory Chemicals Evaluation and Research Institute, Japan (2-7, 3-chome, Miyanojin, Kurume-shi, Fukuoka 839-0801, Japan)
- Age at study initiation: Yearling fish
- Length at study initiation: 7.6-9.7 cm
- Feeding during test
Food type: feed for fry of carp (≥ 43% proteins, ≥ 3% lipid content) supplied by Nippon Formula Feed Mfg. Co., Ltd.
Amount: approximately 2% of the total body weight
Frequency: twice a day in halves (once a day in all at holiday); the fish were starved for 24 hours before sampling

ACCLIMATION
-Acclimation period: After rearing to test fish size in a receiving aquarium, the fish were transferred to an acclimatizing aquarium and acclimatized there after the external disinfection¹. The fish showing any abnormality during this period were removed and the remainder was reared for 39 days in a flow through system at the temperature of 25 ± 2°C. The fish were checked for health conditions and transferred to test tanks. Thereafter the fish were reared at the same temperature in the flow through system for 27 days, following another external disinfection¹.
¹External desinfection was carried out in aqueous solutions containing 50 mg/L oxytetracycline (OTC) for fisheries and 7 g/L NaCl for 24 h.
- Acclimation conditions (same as test or not): same

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

14 mg/L (Ca, Mg)

Test temperature:

23.5-25.0 °C

pH:

7.7-7.9

Dissolved oxygen:

7.7-8.1 mg/L

TOC:

0.7 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 70-L glass tanks
- Renewal rate of test solution (flow rate): 800 mL/min (recorded once a day)
- No. of organisms per vessel at test start: 28 per concentration and 12 for the control
- No. of vessels per concentration (replicates): 1
- No. of vessels per vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: groundwater from the premises of Kurume Laboratory
The dilution water met the requirements of at least one of the following standards: Japanese Ministry of Health and Welfare (Ministerial ordinance of the Ministry of Health and Welfare No. 101, 2003), Japanese water quality criteria for fisheries (Japan Fisheries Resource Conservation Association, 1983), Environmental Quality Standards for Water Pollutants No.14 (Revised February 22, 1999, Environment Agency), OECD TG 210, 1992 ("Fish Early-life Stage Toxicity Test"), OECD TG 305, 1996 (Bioconcentration: Flow-through Fish Test)
- Holding medium different from test medium: no
- Intervals of water quality measurement: temperature and dissolved oxygen once a week, pH of test water twice during the test

OTHER TEST CONDITIONS
- Adjustment of pH: not required
- Photoperiod: 14 hours/day (artificial light of white fluorescent lamp)


RANGE-FINDING / PRELIMINARY STUDY
- Test organism: Oryzias latipes (Orange-red killifish).
- Reason for selection: This species is similar in sensitivity to carp and readily available as test fish.
- Test concentrations: 35 mg/L
- Results used to determine the conditions for the definitive study: 48-hour LC50 > 35 mg/L

Nominal and measured concentrations:

nominal concentration in test water: 20 µg/L (level 1) and 2 µg/L (level 2)
measured average concentration in test water: ≥ 98% of nominal

Reference substance (positive control):

no

Lipid content:

5.22 %

Time point:

start of exposure

Lipid content:

6.05 %

Time point:

end of exposure

Key result

Conc. / dose:

20 µg/L

Type:

BCF

Value:

4.9 L/kg

Basis:

whole body w.w.

Time of plateau:

15 d

Calculation basis:

steady state

Key result

Conc. / dose:

2 µg/L

Type:

BCF

Value:

12 L/kg

Basis:

whole body w.w.

Time of plateau:

15 d

Calculation basis:

steady state

Metabolites:

In the test fish samples, an unknown peak (retention time about 6 minutes) was detected in Level 1 samples (HPLC). This peak was estimated to be a metabolite of the test item in test fish because it was not detected in control fish and in blank samples. Identification of the chemical structure was done by liquid chromatography-mass spectrometry (LC-MS). A standard solution, sample of test fish analysis at Level 1 (after 28 days) and that for control (after 28 days) were analyzed. The metabolite was observed on the chromatogram when mass spectra on the position of the unknown peak was compared with mass spectra of the sample of the test fish at Level 1 and sample of control fish. The peak was emitted in m/z=268, presumed to be phosphoric acid monohydrate diphenyl. BCFs of the metabolite were calculated by conversion to the test item, BCFs ranged from 0.97 to 2.1 L/kg at Level 1. In this case, calculation was performed without correction by recovery rate and using concentrations of test item in test water.

Details on results:

No mortality, abnormality in behaviour and appearance was noted (treated and control)
- Loss of test substance during test period: no
The variation of BCFs (average value) after 15, 22 and 28 days from the initiation of exposure were within ±20% of the average for these days' BCFs. Thus, it was assumed that a steady-state was reached. BCFs were calculated on the basis of these results.

Validity criteria fulfilled:

yes

Remarks:

Temperature variation< ± 2°C, dissolved oxygen ≥60% saturation, variation of test item concentrations within ±20% of the average measured concentrations, no mortality

Description of key information

BCF 4.9 and 12 L/kg (high and low exposure level, respectively)  for Cyprinus carpio (OECD 305)

Key value for chemical safety assessment

BCF (aquatic species):

12 L/kg ww

Additional information

For safety assessment, the BCF value obtained at the low exposure level is used.

The test material shows no bioaccumulation potential in the aquatic environment