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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Administrative data

Endpoint:
bioaccumulation in aquatic species: fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Dec 19, 1991 - March 29, 1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
study performed according to international guidelines and GLPs. water concentrations were higher than later-determined water solubility and achieved with the use of a dispersant which makes actual dissolved exposure unknown. analytcal method specific for ionic bromides.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1991
Reference Type:
publication
Title:
Detection fo feeding behaviour in common carp Cyprinus carpio by using an acceleration data logger to identify mandibular movement.
Author:
Makiguchi et al.
Year:
2012
Bibliographic source:
J Fish Biol 80(6):2345-56.
Reference Type:
publication
Title:
A comparison of the fish bioconcentration factors for brominated flame retardants with their nonbrominated analogues.
Author:
Hardy, M
Year:
2004
Bibliographic source:
Environ Tox Chem 23(3):656-661
Reference Type:
publication
Title:
Environmental Risk Evaluation Report: 1,1'-(Ethane-1,2-diyl)bis[pentabromobenzene] (CAS no. 84852-53-9)
Author:
Dungey SM, Akintoye L
Year:
2007
Bibliographic source:
http://publications.environment-agency.gov.uk/epages/eapublications.storefront/48771dd8022bcfe8273fc0a8029606a9/Search/Run

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: See principles of method if other than guideline
Deviations:
no
Principles of method if other than guideline:
The test was conducted in accordance with "Bioaccumulation test of chemical substance in fish and shellfish" stipulated in the Order Prescribing the Items of the Test Relating to the New Chemical Substance (1974, Order of the Prime Minister, the Minsister of Health and Welfare, the Minister of International Trade and Industry No. 1, Japan) and "305D, Bioaccumulation: Degree of Bioconcentration in Fish" stipulated in the OECD Guidelines for Testing of Chemicals (May 12, 1981).
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
96.3% decabromodiphenyl ethane, 3.6% dodecabromodiphenyl ethane
Radiolabelling:
no

Sampling and analysis

Details on sampling:
Test water analysis was performed twice a week. Test fish analysis was performed every two weeks (n=2 fish/analysis). Control fish analysis: before initiation and at termination of exposure (n=2). Test article stability performed by comparing IR spectra at study initiation and termination.

Test solutions

Vehicle:
yes
Details on preparation of test solutions, spiked fish food or sediment:
The use of a dispersant allowed testing water concentrations higher than what was later determined (by measurement) to be the water solubility of DBDPEthane. Dispersant: crystal sugar and HCO-40 (polyoxyethylene sorbitan monooleate). Test substance was milled with sugar (20 times of test substance) and HCO-40 (20 times of test substance) then dissolved with deionized water to obtain 1000 mg/L stock solution. Stock concentrations of 200 (Level 1) and 20 (Level 2) mg/L were prepared by dilution with deionized water in 25 L glass vessels. Control vessels were prepared with crystal sugar and HCO-40 dissolved in deioninzed water to obtain 4000 mg/L.

Test organisms

Test organisms (species):
Cyprinus carpio
Details on test organisms:
Obtained from Sugishima fish farm (Kumamotot, Japan). Acclimated for 28 d with removal of any abnormal fish. Transferred to test tanks for an additional 35 d. At initiation of exposure; fish mean weight (24.6 g), length (9.8 cm) and 3.7% lipid content.

Fed pelleted feed for carp manufactured by Japan Haigo Shiryo K.K. in an amount corresponding to ~2% of the total body weight of test fish over 2 feedings/day.

Study design

Route of exposure:
aqueous
Test type:
flow-through
Water / sediment media type:
natural water: freshwater
Total exposure / uptake duration:
8 wk
Total depuration duration:
0 d

Test conditions

Hardness:
Total hardness (Ca, Mg) = 106 mg/L
Test temperature:
25 +- 2 degrees C
pH:
not reported
Dissolved oxygen:
Level 1: 6.1 - 7.6 mg/L
Level 2: 6.2 - 7.5 mg/L
Control: 6.8 - 7.7 mg/L
TOC:
not reported
Salinity:
Freshwater
Nominal and measured concentrations:
Doses were selected based on a 48-hr LC50 study in orange-red killifish. A semi static dose range-finding study conducted in Orange-red killifish (Oryzias latipes) for this study provided a 48 hr LC50 of > 50 mg/L. Nominal doses were 0.5 mg/L (Level 1) and 0.05 mg/L (Level 2). The control was prepared in the absence of the test substance. Measured concentration are provided below.
Reference substance (positive control):
no
Details on estimation of bioconcentration:
Bioconcentration factor calculated by dividing the measured concentration in fish tissue by the measured concentration in water with correction for recovery.

Results and discussion

Lipid content
Lipid content:
3.7 %
Time point:
start of exposure
Bioaccumulation factoropen allclose all
Type:
BCF
Value:
< 2.5
Basis:
whole body w.w.
Calculation basis:
other: see text
Remarks on result:
other: Conc.in environment / dose:0.5 mg/L
Type:
BCF
Value:
< 25
Basis:
whole body w.w.
Calculation basis:
other: see text
Remarks on result:
other: Conc.in environment / dose:0.05 mg/L

Any other information on results incl. tables

A peak was detected at the same position as that of the test substance on the IC chromotogram of the control fish both before initiation and at study termination. To take the unknown into account, the range between the maximum and minimum value of the peak's size was used as the minimum limit of detemination (2.l98 - 1.71 = 1.27 ug/g). The measured values in fish were corrected for the unknown. Based on the minimum limit of determination, the minimal BCFs that could be calculated in the study were 2.5 (Level 1) and 25 (Level 2). These minimal BCFs indicate the study was able to detect BCF of concern (e.g. >2000 and >5000).

Measured concentrations in test water (mg/L); average value at the time elapsed from starting of exposure

Week 2

Week 4

Week 6

Week 8

Level 1

0.511

0.516

0.508

0.506

Level 2

0.0517

0.0520

0.0510

0.0507

Concentration of test substance in each fish (μg/g) by week of test.

Week 2

Week 4

Week 6

Week 8

Level 1

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

1.22a

Level 2

N.D.

1.74

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.= Not Detected; a: minimal limit of determination = 1.27 ug/g at a fish weight of 30 g.

Calculated BCFs in each fish by week of study.

Week 2

Week 4

Week 6

Week 8

Level 1

<2.5

<2.5

<2.5

<2.5

<2.5

<2.5

<2.5

<2.5

Level 2

<25

34

<25

<25

<25

<25

<25

<25

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
DBDPEthane did not bioconcentrate in fish(Cyprnus carpio) when tested over an 8 week period. The bioconcentration factor (BCF) was < 2.5 and <25 at exposures of 0.5 mg/L and 0.05 mg/L, respectively, after an 8 week exposure period.  A dispersant was used to achieve these water concentrations. The analytical methodology used was specific for bromide ions and would have detected the presence of parent molecule and metabolites (if any) The lack of bioconcentration observed in this study is consistent with expections based on DBDPEThane's chemical/physical properties, and measured Log Kow and octanol solubility. Neverthless, because the tested concentrations were higher than DBDPEthane's measured water solubility, this result will not be carried forward.

Executive summary:

DBDPEthane did not bioconcentrate in fish(Cyprnus carpio)when tested over an 8 week period. Evidence for the bioconcentration of DBDPEthane was not observed.The reported bioconcentration factors (BCF) were < 2.5 and <25 at a water concentration of 0.5 mg/L and 0.05 mg/L, respectively, at the end of an 8 week exposure period.  The reported BCF values were based on the minimal BCF possible due to the presence of an interferring peak in the controls and nondetectable levels in exposed fish at the majority of time points. (Levels just below the minimal detection limit was report in 1 fish at the upper dose at 8 wks, and 1.74 ug/g bw was detected in 1 fish at the lower dose at week 2. At all other time points concentrations in fish were below the limit of dtermination.)

The analytical method, specific for bromide ions, would have detected the presence of parent molecule plus metabolites (if any). The lack of bioconcentration observed in this study is consistent with the expectation that exposures to DBDPEthane via water will be low and uptake will be poor.

This study has been criticized because a) an interferring peak in control fish increased the detection limit and b) exposure concentrations were higher than DBDPE'thane's water solubility (~0.72 ug/L) determined many years later. The final report stated that the minimal detectable BCF was 2.5 (level 1) and 25 (Level 2). These minimal BCF are below a level of concern with respect to bioconcentration, and from this standpoint the study was capable of measuring a BCF of concern. However, both exposure concentrations were substantially higher than DBDPEthane's measured water solubility, which limits the utility of calculating a BCF from the water concentrations. Because of this, the reported BCF will not be used in the CSR.

We point out that in the wild C. carpio are primarily selective benthic omnivores that specialize in invertebrates that live in sediments (Makiguchi et al. 2012, http://animaldiversity.ummz.umich.edu/accounts/Cyprinus_carpio/). They feed by sucking up mud from the bottom, ejecting it, and then selectively consuming re-suspended items. Carp engage in this activity to the extent of decreasing water quality. It cannot be excluded that some exposure occurred due to the carps' suction feeding mode. DBDPEthane will adsorb to particulates in the water (food, feces), which would then settle to the bottom of the aquaria. The carps' natural feeding behavior could then result in dietary exposure.