1,1'-(1,1,3-trimethylpropane-1,3-diyl)bis(cyclohexane)

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:

28 June to 04 August 2018

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)

Version / remarks:

2004

GLP compliance:

yes

Specific details on test material used for the study:

Appearance: Clear colourless liquid
Batch: 170918339
Purity: 97.2%
Solubility in water: very low

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.1, 1, 100 mg/L
- Sampling method: 6.0 mL of sample were collected from the approximate centre of the test vessels at t=0 h and t=48 h
- Sample storage conditions before analysis: Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 3-d period of magnetic stirring to ensure maximum dissolution of the test item (100 mg/L) in medium. The obtained mixture was allowed to settle for 3 hours. Then, the aqueous Saturated Solution (SS) was collected via siphoning and used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the SS in test medium. All test solutions were clear and colorless at the end of the preparation procedure.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: daphnid
- Strain/clone: Straus, 1820
- Source: In-house laboratory culture with a known history
- Age of parental stock (mean and range, SD): more than two weeks old, 2nd to 5th brood

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

180 mg CaCO3/L

Test temperature:

20°C

pH:

between 7.8 to 8.2

Dissolved oxygen:

8.8 mg/L

Nominal and measured concentrations:

Nominal concentrations: 1.0, 10, 100 mg/L
Measured concentrations of highest test concentration: 0.021 mg/L at the start of test; 0.014 mg/L at the end of test

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL, all-glass
- Material, size, headspace, fill volume: 50 mL of test solution
- Aeration: None
- No. of organisms per vessel: 5 organisms/vessel
- No. of vessels per concentration (replicates): 4 for 100 mg/L; 2 for 10 mg/L; 2 for 1.0 mg/L
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water purified by Reverse Osmosis

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: A daily photoperiod of 16 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : At 24 hours and at 48 hours

RANGE-FINDING STUDY
- Test concentrations: combined limit/range-finding test was performed; solutions containing 1.0, 10 and 100% of the saturated solution prepared at a loading rate of 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.017 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (dissolved fraction)

Remarks:

0.017 mg/L

Basis for effect:

mobility

Remarks on result:

other: Average of exposure concentration considered to represent maximum solubility of test item

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Loading rate

Results with reference substance (positive control):

- Results with reference substance valid? Yes

No immobility was observed in the control and at any of the test concentrations throughout the exposure period, except for one daphnid that was immobile at the end of the test in the highest concentration. It should be noted that up to10% immobility is accepted in the control, and therefore effects below 10% were considered biologically not relevant.

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 for Daphnia magna exposed to 1,1’-(1,1,3-trimethylpropane-1,3-diyl)bis(cyclohexane) was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 0.017 mg/L being considered to represent the maximum solubility of the test item in test medium at a loading rate of 100 mg/L.

Description of key information

The 48h-EC50 for Daphnia magna exposed to 1,1’-(1,1,3-trimethylpropane-1,3-diyl)bis(cyclohexane) was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 0.017 mg/L being considered to represent the maximum solubility of the test item in test medium at a loading rate of 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L