4-methylbenzyl alcohol

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:

2017-05-04 to 2017-06-17

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

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)

Analytical monitoring:

yes

Details on sampling:

For the determination of the actual test item concentration, duplicate samples were taken at the start and at the end of the test (after 48 hours) from the single test concentration of 100 mg/L and from the control. For the 48-hour stability samples, the contents of the respective replicates
were combined prior to sampling.
Immediately after sampling, all samples were frozen (at -20 ± 5 °C). Based on pre-experiments for investigation of the storage stability (actual study), the test item was found to be stable in the test water under these storage conditions.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The test medium of the nominal concentration of 100 mg/L was prepared by dissolving 50.04 mg of the test item completely in 500 mL of test water using ultrasonic treatment for 15 minutes and intense stirring for 15 minutes at room temperature. After the dissolving procedure the single test concentration of 100 mg/L was a clear solution. The test medium was prepared just before the introduction of the daphnids.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Strain: Straus
- Source: Daphnia Collection of the University of Basel/Switzerland in 2015
- Age of test organisms: 6 - 24 h
- Feeding during test: no

ACCLIMATION
- Acclimation period: no
- Acclimation conditions: same as test
- Type and amount of food: Desmodesmus subspicatus or a commercial fish diet (Tetra Min® Hauptfutter, supplied by TETRA-GmbH, 49324 Melle / Germany)
- Feeding frequency: three times a week
- Health during acclimation: no mortality observed

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20 - 21 °C

pH:

7.8 - 7.9

Dissolved oxygen:

8.5 - 8.8 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentration (0 h): 105 mg/L
Measured concentration (48 h): 107 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers
- Type: closed with glass plates to reduce the loss of water by evaporation and to avoid the entry of dust into the solutions
- Size, fill volume: 100 mL, 50 mL
- Aeration: yes
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 1 Daphnid - 10 mL

TEST MEDIUM PARAMETERS
- Preparation of dilution water: Reconstituted test water (ISO Test water) according to OECD Guideline No. 202

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16-hour light to 8-hour dark cycle with a 30-minute transition period
- Light intensity: 15 and 17 μmol m-2 s-1

EFFECT PARAMETERS MEASURED:
Immobility was determined by visual inspection after 24 and 48 hours
Observations were also performed for other non-lethal effects (e.g. abnormal behavior or appearance).

RANGE-FINDING STUDY
- Test concentrations: 1.0, 10, 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.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: no abnormalities
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

For evaluation of the quality of the daphnia clone and the experimental conditions, potassium dichromate is tested as a positive control twice a year. The result of the latest positive control test in March 2017 (24-hour EC50: 1.2 mg/L) showed that the sensitivity of the test organisms was within the range given by the guideline (24-hour EC50: 0.60-2.1 mg/L).

Reported statistics and error estimates:

The NOEC, EC0, EC50 and EC100 were directly determined from the raw data.

In the control and in the test item concentration of 100 mg/L, no daphnids showed immobilization or other signs of disease or stress (e.g., discoloration or unusual behavior such as trapping at the surface water) during the test period of 48 hours

Table 1. Analytical Results for Test Samples

Sampling Day/ Sample Age [d/h]	Nominal Concentration of Test Item cnom [mg/L]	Measured Concentration  of Test Item x [mg/L]	Sample Preparation Factor F	Determined Concentration of Test Item c [mg/L]	% of Nominal Concentration
0/0	Control	n.d.	2	< LOQ	n.a.
(fresh)	100	52.9 and 52.4	2	105	105
3/72	Control	n.d.	2	< LOQ	n.a.
(aged)	100	53.4 and 53.2	2	107	107

n.d.       = no test item detected

n.a.        = not applicable

LOQ:    6.8 mg/L

The tabulated values of the samples represent rounded results obtained by calculation using the exact raw data.

Validity criteria fulfilled:

yes

Conclusions:

The test item had no acute toxic effects on Daphnia magna in a 48-hour static test up to the nominal concentration of 100 mg/L.

Executive summary:

The acute toxicity of the test item on Daphnia magna was determined in a 48-hour static test according to the OECD Guideline for Testing of Chemicals, No. 202 (2004). A limit test was performed in accordance with the test guidelines to demonstrate that the test item has no toxic effect on the test organisms up to and including a nominal concentration of 100 mg/L. Thus, the only nominal concentration tested was 100 mg/L. Additionally, a control group was tested in parallel. The average of the measured concentrations of the test item in the test medium of the single test concentration of 100 mg/L was 105 and 107 % of nominal value at the start and the end of the test, respectively. Thus, the test item was stable in the test medium over the test period of 48 hours. Therefore, the endpoint values were related on the nominal concentration of 100 mg/L. The 48 -hour EC50 and EC100 values were >100 mg/L.

Description of key information

The test item had no acute toxic effects on Daphnia magna in a 48-hour static test up to the nominal concentration of 100 mg/L according to OECD 202 (2004).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The acute toxicity of the test item on Daphnia magna was determined in a 48-hour static test according to the OECD Guideline for Testing of Chemicals, No. 202 (2004). A limit test was performed in accordance with the test guidelines to demonstrate that the test item has no toxic effect on the test organisms up to and including a nominal concentration of 100 mg/L. Thus, the only nominal concentration tested was 100 mg/L. Additionally, a control group was tested in parallel. The average of the measured concentrations of the test item in the test medium of the single test concentration of 100 mg/L was 105 and 107 % of nominal value at the start and the end of the test, respectively. Thus, the test item was stable in the test medium over the test period of 48 hours. Therefore, the endpoint values were related on the nominal concentration of 100 mg/L. The 48-hour EC50 and EC100 values were >100 mg/L.