Ethyl trans-2,2,6-trimethylcyclohexanecarboxylate

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:

20 December 1993 to 14 February 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

other: the requirements of the Japanese Ministry of International Trade and Industry's Chemical Substances Control Law Clause No. 117, (1973)

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Vehicle:

yes

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

Preparation of test media : Preliminary solution in tetrahydrofuran (Fisons AR Grade) 255 mg of test material was dispersed in solvent and the volume adjusted to 100 ml to give a 255 mg/100 ml solvent stock solution. 10 ml of this stock solution were dispersed in solvent and the volume adjusted to 100 ml to give a 25.5 mg/ 100 ml solvent stock solution. A range of pre-study test samples were prepared in bottles and analysed initially and then after storage at ambient temperature in light and dark conditions over a 24-hour period.The test samples have been considered to be sufficiently stable for the purposes of this study.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Test species: Common Carp (Cyprinus carpio).
Supplier: Neil Hardy Aquatica Ltd., Carshal ton, Surrey, U.K.
Acclimatisation: Stock held since 6 December 1993 and acclimatised to test conditions from 6 December - 20 December 1993. The fish were maintained in a glass tank with a "single pass" water renewal system. The lighting was controlled to give a 16 hours light : 8 hours darkness cycle.
Mean standard length: 9.9 cm* (SD = 0.4 cm).
Mean weight: 29.5 g* (SD = 4.8 g).* values given are the means from the measurement of nine sample fish.
Mean lipid content: 3.8 %
Mortalities: Zero in the 7 days prior to the start of the study.
Medication: None.
Feeding Commercial carp pellets. Daily .

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

other: Laboratory tap water dechlorinated by passage through an activated carbon filter.

Total exposure / uptake duration:

56 d

Hardness:

Total hardness approximately 100 mg/l as calcium carbonate

Test temperature:

25°C

pH:

7.2 to 7.8

Dissolved oxygen:

>/=7.3 mg O2/L

TOC:

No data

Salinity:

Not applicable

Conductivity:

Mean: 298 uS/CM

Details on test conditions:

Test Water: Laboratory tap water dechlorinated by passage through an activated carbon filter.
Test conditions:
Test vessels: Glass aquaria holding 100L of test media, fitted with lids and sealed to prevent losses of test material through volatilisation. The solvent control test vessel was set up in a separate laboratory area in order to eliminate the possibility of contamination by test material lost from the test vessels due to the volatile nature of the test material.
Experimental design: 2 test concentrations plus 1 solvent control (including 33.3 ul/l auxiliary solvent).18 fish per test concentration.Test concentrations: 0.0085 and 0.085 mg/l . Media renewal: Continuous at 800 ml/min. The diluent was supplied at a rate of 800 ml/min by a metered gravity feed system and the solvent stock solutions for the test concentrations 0.0085 and 0.085 mg/l were pumped at a rate of 1.6 ml/hour by a Harvard "22" multiple syringe infusion pump. The solvent control was dosed with tetrahydrofuran at a rate of 1.6 ml/hour by a Braun Perfusor Secura syringe pump. The dosing apparatus was setu approximately 24 hours prior to the start of the study to allow equilibration of the test concentrations. Method of initiation: Fish were placed, at random, in prepared test media. Feeding regime: Commercial carp pellets. Fish were fed approximately 2% of body weight daily. Excess food and detritus were siphoned from tanks daily. Loading: 5.3 g bodyweight/l (static volume).0.46 g bodyweight/l (volume in 24 hours) at 11.52 tank volumes per day.
Photoperiod: 16 hours light : 8 hours dark.
Aeration: none
Duration of test: 56 days

Nominal and measured concentrations:

Nominal: 0.085 mg/L, mean measured test concentrations: Day 14: 0.00576 mg/L, Day 28: 0.00603 mg/L, Day 42: 0.00603 mg/L, Day 56: 0.00593 mg/L
Nominal: 0.085 mg/L, mean measured test concentrations: Day 14: 0.0535 mg/L, Day 28: 0.0545 mg/L, Day 42: 0.0572 mg/L, Day 56: 0.0585 mg/L

Reference substance (positive control):

no

Lipid content:

< 0.001 mg/kg bw d.w.

Time point:

start of exposure

Remarks on result:

other: correspondig to L.O.Q.

Lipid content:

0.797 mg/kg bw d.w.

Time point:

end of exposure

Remarks on result:

other: Nominal concentration of 0.0085 mg/ L

Lipid content:

9.3 mg/kg bw d.w.

Time point:

end of exposure

Remarks on result:

other: Nominal concentration of 0.085 mg/ L

Key result

Conc. / dose:

0.009 mg/L

Temp.:

25 °C

Type:

BCF

Value:

134 dimensionless

Basis:

whole body d.w.

Key result

Conc. / dose:

0.085 mg/L

Temp.:

25 °C

Type:

BCF

Value:

159 dimensionless

Basis:

whole body d.w.

Details on results:

There were no mortalities or other adverse reactions to exposure observed in any of the fish in the control and test vessels throughout the duration of the study.

The results from the analysis of the test water samples showed that the mean measured test concentrations for the 0.0085 and 0.085 mg/l test concentrations were 70% and 69% of nominal test concentrations respectively. The marked decline in test material concentrations in the water samples are considered to be a result of the highly volatile nature of the test material given that the test material has been shown to be chemically stable in water over a 24 hour period. From the calculation of test material half-life based on Henry's law constant the half life of ET-344 SP in water is calculated as being 2.55 hours. Therefore, it is considered that the dosing apparatus employed in the study provided the best possible method of maintaining the test material concentrations near nominal given that the diluent flow rates throughout the duration of the study varied by only +/- 1% and the volumes of solvent stock solutions dosed over each 24-hour long period were correct.

The results of the analysis of the test fish tissues showed that ET-344 SP accumulated in the body tissues of fish. The day 56 Bioconcentration Factors (BCF's) were 134 at a test concentration of 0.0085 mg/l and 159 at a test concentration of 0.085 mg/l. However, this level of accumulation over an eight week period is not considered to represent a significant value given that only BCF values in excess of 500 are considered to represent a significant accumulation of test materia1 (Nishi kawa (1990), EEC (1993)).

A BCF value of 439 was obtained on day 14 at the test concentration of 0.0085 mg/l and was observed to "decline" during the study to give BCF values 183 on day 28, 127 on day 42 and 134 on day 56. This "decline" in BCF value is considered to be due to an initial uptake of the test material into the fish body tissue followed by elimination by excretion and/or metabolism of the test material.

Validity criteria fulfilled:

yes

Conclusions:

The Bioconcentration Factors (BCF) for ET-344 SP after 56 days were calculated to be 134 at a test concentration of 0.0085 mg/l and 159 at a test concentration of 0.085 mg/l.The best material, ET-344SP, cannot be considered to significantly accumulate in the tissues of common carp.

Executive summary:

TEST MATERIAL: ET-344 -SP

TEST TYPE: Assessment of Bioaccumulation of a Chemical Substance in Common Carp according to OECD Guideline No. 305C "Bioaccumulation : Test for the Degree of Bioconcentration in Fish" and the requirements of the Japanese Ministry of International Trade and Industry's Chemical Substances Control Law Clause No. 117, (1973).

TEST SPECIES: Common Carp (Cyprinus carpio)

DURATION: 56 days

REULTS

Acute Toxicity to Killifish

The 48-hour LC540 from the exposure of killifish to ET-344 SP was calculated to be 8.5 mg/l.

Bioaccumulation in carp

The Bioconcentration Factors (BCF's) for ET-344 SP, in common carp, after 56 days were calculated to be 134 at a concentration of 0.0085 mg/l and 159 at a concentration of 0.085 mg/l.

Description of key information

The Bioconcentration Factors (BCF) for ET-344 SP after 56 days were calculated to be 134 at a test concentration of 0.0085 mg/l and 159 at a test concentration of 0.085 mg/l.

Therefore, the test material, ET-344SP, cannot be considered to significantly accumulate in the tissues of common carp.

Key value for chemical safety assessment

BCF (aquatic species):

159 dimensionless

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