Cyclohexanemethanol, 4-(1-methylethyl)-

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:

August 2, 2011 to October 16, 2012

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:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Inspected on July 19-21, 2011 / Signed on August 31, 2011

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Purity test date: March 21, 2012

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 1.0, 5.6, 10, 18, 32, 56, 100
- Sampling method: Water samples were taken from the control and each test group (replicates R1 – R4 pooled) at 0 and 48 hours for quantitative analysis.
- Sample storage conditions before analysis: -20 °C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test item was dissolved directly in reconstituted water with the aid of prolonged stirring.
- Controls: 0 mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The test preparations were observed to be clear, colourless solutions throughout the duration of the test.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia
- Strain: Daphnia magna
- Source: in house laboratory cultures
- Age at study initiation (mean and range, SD): less than 24 hours (a small minority may have been up to 28 hours old)
- Method of breeding: cultured
- Feeding during test: no

ACCLIMATION
- Acclimation period: daphnia were cultured in laboratory and used when less than 24 hours old
- Acclimation conditions (same as test or not): same as test - 20°C, 16 hours light, 8 hours dark
- Type and amount of food: algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension.
- Feeding frequency: daily
- Health during acclimation (any mortality observed): NR

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

approximately 250 mg/L as CaCO3

Test temperature:

22 °C

pH:

8.0-8.2

Dissolved oxygen:

95-103%ASV

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: 0 (control), 1.0, 5.6, 10, 18, 32, 56, 100
Measured (0 hours): Measured (45 hours):

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass beakers
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 250 mL of test preparation
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water and deionised reverse osmosis water

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod:16 hours of light, 8 hours dark
- Light intensity: 928 to 942 lux

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Nominal - 0 (control), 1.0, 5.6, 10, 18, 32, 56, 100
- Range finding study: yes
- Test concentrations: Nominal - 0.10, 1.0, 10 and 100 mg/L.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL = 11-15

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 14-18

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

LOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: 0

Results with reference substance (positive control):

- Results with reference substance valid? within normal range
- Mortality: yes
- EC50/LC50: 48 hour EC50 = 1.1 mg/L

Reported statistics and error estimates:

Analysis of the immobilization data by the trimmed Spearman-Karber method (Hamilton et al, 1977) at 24 hours and the probit method (Finney, 1971) at 48 hours based on the nominal test concentrations.

Validity criteria fulfilled:

yes

Conclusions:

The 48 hour EC50 was 13 mg/L (based on nominal concentrations, measured concentrations were >80% to nominal).

Executive summary:

A study was performed, according to OECD Guideline 202 and EU Method C.2, to assess the acute toxicity of the test item to Daphnia magna. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at concentrations of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 22 °C under static test conditions. The number of immobilized Daphnia were recorded after 24 and 48 hours. The 48-Hour EC50 for the test item to Daphnia magna based on nominal test concentrations was 13 mg/L with 95% confidence limits of 11 - 15 mg/L. Analysis of the test preparations at 0 and 48 hours showed measured test concentrations to range from 89% to 117% of nominal value and so the results are based on nominal test concentrations only.

Description of key information

The substance was harmful to Daphnia magna when tested according to OECD Guidelines for Testing of Chemicals (April 2004) No 202. The EC50 observed after 48 hours was 13 mg/L (based on nominal concentrations, measured concentrations were >80% to nominal).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

13 mg/L

Additional information

Acute toxicity to Daphnia magna was assessed according to OECD Guidelines for Testing of Chemicals (April 2004) No 202, and in compliance with OECD GLP (Harland Laboratories, 2012).  Daphnia were exposed under static conditions to the substance at a range of concentrations from 1 to 100 mg/L in freshwater. The test was performed with 5  Daphnia per vessel and 20  Daphnia per concentration. For each concentration, the percentage of immobilisation at 24 hours and 48 hours was recorded, and test concentrations were confirmed by GC analysis. The No Observed Effect Concentrations (NOEC) after 24 and 48 hours exposure were 10 and 5.6 mg/L respectively. The Lowest Observed Effect Concentration (LOEC) was considered to be 10 mg/L. The EC50 after 24 and 48 hours exposure were 16 and 13 mg/L respectively. The following validity criteria were met: immobilisation in the control did not exceed 10% at the end of the test; concentrations of dissolved oxygen in the test vessels remained above 2 mg/L at the end of the test; pH did not vary by more than one unit throughout the test; and the concentrations of the test substance remained within 80% of the initial concentration throughout the test. Under the conditions of the test, the 48-hour EC50 was 13 mg/L (based on nominal concentrations, measured concentrations were >80% to nominal).