2,2'-dimorpholinyldiethyl ether

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:

1993-09-22 to 1993-12-06

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Well performed study performed according to a guideline very similar to OECD guideline 305C and compliant with GLP requirements. The results can be considered reliable with restrictions because not all requirements of the current OECD 305 guideline have been fulfilled. For instance, no depuration phase has been studied and a smaller amount of fish has been sampled at each sampling occasion.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 6950-77-8,9
- Analytical purity: 99.12 wt %
- Impurities (identity and concentrations): hydroxyethoxyethylmorpholine 0.78 wt %, dimorpholinoethane 0.05 wt %

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: chilled dark place
- Stability under test conditions: confirmed by preliminary test
- Stability during storage: confirmed by comparison of IR spectrum of starting sample with that of test substance after storage

OTHER SPECIFICS:
- Name of test material (as cited in study report): bis(2-morpholinoethyl)-ether
- Molecular formula: C12H24N2O3
- Physical state: yellow-brown liquid

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: 2 test fish were analysed every two weeks (2nd, 4th, 6th and 8th week), 2 control fish were analysed at the beginning and termination of the test
- Sampling intervals/frequency for test medium samples: one test water sample was analysed twice a week
- Sample storage conditions before analysis: no details reported

Vehicle:

no

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

PREPARATION OF TEST SOLUTION
- Test substance was dissolved in deionized water to obtain 2000 mg/L of stock solution.
- For spiking the aquaria, two other stock solutions (400 mg/L and 40 mg/L) were prepared by dilution of the original stock solution with deionized water.
- A sufficient amount of these stock solutions was then added to the test vessels under consideration.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: carp
- Strain: not reported, used fish originated from lot n° TFC-930715
- Source: Sugishima fish farm, 123-2 Gunchika Ichibancho, Yatsushiro-shi, Kumamoto 866, Japan
- Length at study initiation (lenght definition, mean, range and SD): average 9.1 cm
- Weight at study initiation (mean and range, SD): average 21.4 g
- Lipid content: average 4.2 %
- Weight at study termination: approximately 35.5 g (nominal concentration 2 mg/L), approximately 33.05 g (nominal concentration 0.2 mg/L), approximately 34.1 g (control)
- Feeding during test: yes, except for day of fish sampling
- Food type: pelleted feed for carp
- Amount: amount corresponding to about 2 % of the total body weigh of test fish (per day)
- Frequency: twice a day by halves

FISH KEEPING
- Health status: at reception, fish showing visible abnormal signs were removed and other fish were externally desinfected
- Fish were reared in flow through system for 6 days
- After 6 days fish were desinfected again and transferred to the acclimatization tank

ACCLIMATION
- Acclimation period: after a first period of 37 days, fish were desinfected once more and moved to test tanks for 26 days prior to test
- Acclimation conditions (same as test or not): same as test conditions

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

8 wk

Hardness:

117 mg/l (Ca, Mg)

Test temperature:

25 ± 2 °C

pH:

Not reported.

Dissolved oxygen:

ranging from 7.0 to 8.2

TOC:

Not reported.

Salinity:

Not applicable.

Details on test conditions:

TEST SYSTEM
- Material, size, headspace, fill volume: 100-L glass aquaria
- Aeration: not specified
- Type of flow-through (e.g. peristaltic or proportional diluter): micro quantitative pump (Tokyo Rika Kikai co., Ltd. type GMW)
- Renewal rate of test solution (frequency/flow rate): 579 L/day of test water (2 mL/min stock solution and 400 mL/min dilution water)
- No. of organisms per vessel: 11 fish for each test treatment, 5 fish for the control
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: underground water pumped up from the ground of Kurume Research Laboratories
- Intervals of water quality measurement:
* water temperature, pH and dissolved oxygen were continuously monitored
* total hardnes, evaporated residue, chemical oxygen demand, chloride ion, ammoniacal nitrogen, harmful substances such as organic phosphorus compounds, cyanide ion and heavy metal ions are analyzed regularly once every six months

OTHER TEST CONDITIONS
- Adjustment of pH: not specified, assumed not
- Photoperiod: not specified

PRELIMINARY STUDY
- Acute toxicity to fish
- Test concentrations: 0, 1000 mg/L
- Test species: Oryzias latipes (orange-red killifish)
- Test type: determination of LC50 (48h)
- Results used to determine the conditions for the definitive study: LC50 (48h) >= 1000 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0, 0.2, 2 mg/L test substance.
Measured concentrations: control not measured, 0.204 and 0.199 mg/L at start and end respectively for 0.2 mg/L, 2.05 and 2.03 mg/L at start and end respectively for 2 mg/L.

Reference substance (positive control):

no

Details on estimation of bioconcentration:

BCF (L/kg) = concentration in fish (mg/kg ww) / concentration in water (mg/L)

Type:

BCF

Value:

2.9 - 3.1 L/kg

Basis:

whole body w.w.

Time of plateau:

4 wk

Calculation basis:

steady state

Remarks on result:

other: range over whole uptake phase = 1.9-3.1 L/kg ww

Remarks:

Conc.in environment / dose:2 mg/L (nominal)

Details on kinetic parameters:

Not determined (not possible because no depuration phase included).

Details on results:

No abnormality in behavior and appearance of the test fish was observed.
No mortalities observed.
BCF values for the 0.2 mg/L treatment were reported to be <= 4.9 L/kg because no measurable test substance was present in the exposed fish.
Steady state appears to be reached at ca. 4 weeks, which is the typical duration of the uptake phase in the new OECD guideline. Therefore the BCF values reported for this uptake duration were reported in the results box.

Validity criteria fulfilled:

yes

Conclusions:

This study investigated the uptake of the test substance by carp (Cyprinus carpio) during 8 weeks of exposure to concentrations of 0.2 and 2 mg/L. No mortalities were observed during the exposure period. Frequent samples were taken of both water and fish. The plateau of the uptake phase seems to be reached after ca. 4 weeks, resulting in BCF values of 2.9-3.1 L/kg ww (results for the 2 mg/L treatment). Overall, the BCF values varied between 1.9 and 3.1 L/kg ww. For the 0.2 mg/L treatment BCF values were reported to be <= 4.9 L/kg because no measurable test substance concentrations were present in the fish samples.

Description of key information

The key value for aquatic bioaccumulation was derived from a study exposing carp (Cyprinus carpio) to 2 mg/l of test substance over a period of 8 weeks under GLP conditions and following a guideline similar to OECD 305 C. 

Key value for chemical safety assessment

BCF (aquatic species):

3 L/kg ww

Additional information

One study reporting on the BCF of the test substance was available. In this study from Kurume Research Laboratories (Yakata, 1993), carp (Cyprinus carpio) were exposed to 0.2 and 2 mg/l (nominal concentration; actual concentrations were in agreement) of the test substance in a flow-through system over a period of 8 weeks. Steady-state was reached after 4 weeks, so BCF values are reported for this uptake duration. BCF values for the 0.2 mg/l treatment were reported to be <= 4.9 L/kg because no measurable test substance was present in the exposed fish.

The plateau of the uptake phase seems to be reached after ca. 4 weeks resulting in BCF values of 2.9 -3.1 L/kg ww (results for the 2 mg/L treatment). Overall, the BCF values varied between 1.9 and 3.1 L/kg ww.