Bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-04-30 to 2009-09-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

Batch No.: 20090226
Purity: 99.38%

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by chemical analysis. Water samples were taken from the controls and each exposure level at the start (0h), before and after renewing of test solution (24 hours) and at the end (48 hours) of the test for analysis.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
201 mg of test substance was added to 2 L OECD media to prepare 100 mg/L of nominal test concentration of test solution. This solution ws homogenized with ultra-homogenizer for 30 minutes and stirred for about 48 hours to ensure that the limit of solubility was reached. After 48 hours the test solution was centrifuged to remove any undissolved test substance, in this way Water Accomodated Fractions (WAFs) of the test substance in test media were prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: Bred in house; originally from Carolina Science and Math, United States
- Age at study initiation: < 24 hrs
- Length at study initiation (length definition, mean, range and SD):
- Method of breeding: Cultured under 16 hr light/8 hr dark cycle at 18-22 °C in glass beakers containing 3 L of M4 medium. Cultures were fed daily with a suspension of algae (Chlorella sp.) supplying 0.1-0.2 mg Carbon/animal/d. Culture conditions ensured reproduction was by parthenogenesis.
- Feeding during test: None

Test type:

other: Daily batch-wise renewal of the test solution to ensure the maintenance of satisfactory environmental conditions and exposure levels.

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

No data

Test temperature:

19.4 °C ± 0.2 °C

pH:

7.63-7.87

Dissolved oxygen:

8.2 - 9.3 mg/L

Salinity:

No data

Nominal and measured concentrations:

Nominal concentration of 100 mg/L (water accomodated fraction)
Mean measured concentration of 0.17 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 120 mL volume crystallizing dish containng 100 mL of test solution, lossely covered with glass to prevent evaporation.
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light/8 hours dark
- Light intensity: 694 to 707 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Daphnia were examined daily for symptoms of intoxication and immobilisation. The animals were considered to be immobilised of they were unable to swim for apprximately 15 seconds.

TEST CONCENTRATIONS
- Single limit concentration used.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.17 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: At limit of solubility (water accommodated fraction)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.17 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: At limit of solubility (water accommodated fraction)

Details on results:

There was no immobilization of the daphnids expsoed to control. However 5% of immobilization and 45% of lethargic symptoms (erratic swimmng) were observed at the end of the test in the nominal concentration of 100 mg/L WAFs (mean measured concentration: 0.17 mg/L).

Reported statistics and error estimates:

No statistical analysis was done because the limit test was carried out with only one test concentration. The EC50 values were expressed as above this concentration.

Validity criteria fulfilled:

yes

Remarks:

Met the following validity criteria: 1. Immobilisation of Daphnia in the control ≤ 10 %: Yes, 0 %. 2. Dissolved O2 conc. at the end of the test in control and test vessels ≥ 3 mg/L: Yes, 8.2-9.3 mg/L.

Conclusions:

The 48 h EC50 value expressed in terms of the mean measured concentration of the test substance to Daphnia magna was determined as > 0.17 mg/L.

Description of key information

48 h EC50 >0.17 mg/L (mean measured concentration). OECD 202.

Additional information

The toxicity of the test substance was determined by preparing water accommodated fractions (WAFs).The mean concentration (geometric average) of the test substance measured at the nominal concentration of 100 mg/L WAFs during the test was 0.17 mg/L. The 48 h EC50 value expressed in terms of the mean measured concentration was determined as > 0.17 mg/L.