1-Methyl-4-[(trans,trans)-4'-propyl[1,1'-bicyclohexyl]-4-yl] -benzene

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 24, 2013 - Feb 13, 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch: N012062946
Appearance: White, crystalline solid

Analytical monitoring:

no

Details on sampling:

No analytical monitoring was performed during the test period, because the test item has a very low water solubility and is therefore not quantifiable in the tested saturated solution in sufficient manner, even with enrichment of the samples.

Vehicle:

yes

Remarks:

Elendt M4, according too ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A saturated solution (100 mg/L) was prepared with dilution water one day before start of each exposure interval. The test item (100 mg/L) was tranferred with an appropriate amount of the dilution water into brown glass flask and ahaken overhead with 20 rpm for 24 hours at room temperature. Undissolved test item was removed by filtration with a membrane filter (0.45 µm, RC, Machery-Nagel).
- Vehicle: Elendt M4, according too ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Daphnia magna Straus (Clone 5)
- Source: lnstitut für Wasser-, Boden- und Lufthygiene (WaBolu)
- Breeder: DR.U. NOACK-LABORATORIEN, Kathe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Feeding during test: Daily feeding per test vessel with Pseudokirchneriella subcapitata (0.165 - 0.219 mL) and Desmodesmus subspicatus (0.228 - 0.922 mL) suspension was provided as food corresponding to 0.2 mg C per Daphnia and day.

ACCLIMATION
- Acclimation period: At least 2h in dilution water
- Acclimation conditions: same as test
- Type and amount of food: At least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus, with an algae cell density of > 10^6 cells/mL

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

153 - 180 mg/L CaCO3

Test temperature:

20.6 - 21.6°C

pH:

7.59 - 8.59

Dissolved oxygen:

5.21 - 9.53 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers 100 mL capacity
- Type : open
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution: renewal 3 times per week, i.e. after 48 and 72 hours
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Culture medium Elendt M4, according to ELENDT ( 1990), modified to a total hardness of 160 to 180 mg CaCO3/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: once within 7 days

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8h light/dark cycle
- Light intensity: Max. 20 µE m-2 s-1

TEST CONCENTRATIONS
- Range finding study: A non GLP preliminary range finding test was carried out at the test facility as acute immobilisation test to Daphnia magna STRAUS. A limit loading rate of 100 mg/L of the test item was tested under static conditions over a period of 48 h and no immobilisation was seen.

Reference substance (positive control):

yes

Remarks:

A reference test was conducted as an acute immobilisation test (acc. to DIN 38412 L11 and AQS P 9/2) under static conditions with a test duration of 24h once per month.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

No analytical monitoring was performed during the test period, because the test item has very low water solubility and is therefore not quantifiable in the tested saturated solution in sufficient manner, even with enrichment of the samples. Th water solubility of the test item was estimated by caluclation with EPISuite developed by EPA to be < 0.28 µg/L. The limit of quantification of the used HPLC-DAD system was set to be 0.2 mg/L and is obviously much higher than the estimated water solubility. Even an enrichment of the samples by factor 1000 is not sufficient enough so that the test item cannot be determined above the LOQ. Higher enrichment factors are actually not practibale because of the high volumes of the saturated solution needed for enrichment. Therefore, a HPLC standard method with sufficient sensivity and accuracy could not be established.

The nominal loading level of the test item of 100 mg/L was used for the assessment of the effect levels.

The average value of living juveniles per parental daphnid was 81 for the control and 78 for the nominal loading level of 100 mg/L after 21 days. The reproductive output of daphnids at the nominal loading level of 100 mg/L was therefore comparable to the reproductive output of daphnids in the control (t-test, p = 0.05).

The coefficient of varation of the number of living offspring produced per parent was 10% for the control and 9% for the nominal loading level of 100 mg/L. Generally in a well-run test, the coefficient of varation around the mean number of living offspring per parent animal should be <= 25%.

The intrinsic rates of natural increase (IR) of the surviving parental daphnids accounting for generation time and number of offspring were used for calculation of population growth and maintenance.

No adult mortality was observed during the test period of 21 days. In the nominal loading level of 100 mg/L and in the control, all parental daphnids survived until the end of the test after 21 days.

The first brood was released between days 8 and 9 by all parental daphnids of the control and the nominal loading level of 100 mg/L. Four broods were produced by all parental daphnids in the nominal loading level of 100 mg/L and the control.

The mean dry body weight and total body length of all parental daphnids of the nominal loading level of 100 mg/L and the control were determined at the end of the study. The mean dry body weight of the parental daphnids was 0.82 mg per daphnid for the control and 0.77 mg per daphnid for the nominal loading level of 100 mg/L. The mean body lenth of the parental daphnids was 4.98 per daphnid for the control and 5.18 mm per daphnid for the nominal loading level of 100 mg/L.

No stillborn juveniles or aborted eggs were observed in the control during the exposure period of 21 days. Only one aborted egg was observed at the nominal loading level of 100 mg/L during the exposure rate.

No males or ephippia (winter eggs) were observed in the control or in the nominal loading level of 100 mg/L.

Water quality parameters (i.e. pH-value, dissolved oxygen concentration, total water hardness and temperature) were within the acceptable limits.

Results with reference substance (positive control):

The EC50 of the reference item ptassium dichromate was 1.68 mg/L (95% confidence limits: 1.65 - 1.70 mg/L) after 24 hours and therefore within the prescribed concentration range of 0.6 - 2.4 mg/L of quality criteria according to AQS P 9/2 (02/2000) for daphnids clone 5 cultured in Elendt M4 medium. The EC50-value of the reference item is also within the recommended rangeof 0.6 - 2.1 mg/L according to OECD-Guideline 202.

Validity criteria fulfilled:

yes

Conclusions:

At the saturated solution of the test item prepared with a nominal loading of 100 mg/L, no biologically or statistically significant effects on the reproductive output were determined.

Based on the nominal loading level of the test item, the No Observed Effect Concentration (NOEC) was 100 mg/L.

Executive summary:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 211. In this study semi-static conditions have been applied.

At the saturated solution of the test item prepared with a nominal loading of 100 mg/L, no biologically or statistically significant effects on the reproductive output were determined.

Based on the nominal loading level of the test item, the No Observed Effect Concentration (NOEC) was 100 mg/L.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For this endpoint information from a structural similar compound is available. This study for this similar compound was performed according to GLP and the methods applied are fully compliant with OECD TG 211. See chapter 13 report for a more detailed justification.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Conclusions:

For this endpoint information from a structural similar compound is available. This study for this similar compound was performed according to GLP and the methods applied are fully compliant with OECD TG 211. See chapter 13 report for a more detailed justification.

Description of key information

GLP OECD 211: NOEC = 100 mg/L (nominal), saturated solution

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The test substance had no effect on the reproductive performance of Daphnia magna up to the limit of 100 mg/L (nominal) as tested in a GLP compliant OECD 211 assay.