α,α,α-trifluoro-m-cresol

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: DIN 38412, Part II (Daphnia short-time test)

Version / remarks:

(German Institute of Standardization, 1982).

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The solutions were prepared with 'dilution water'. The concentration steps were selected so as to give 3-4 EC values in a range between EC0 and EC100, of which at least one value was below and one above EC50.
- Controls: positive control.
- Chemical name of vehicle: dilution water. The dilution water used had a specific composition: acid capacity K(s4.3) of 0.8 mmol/L, total hardness of 2.4 mmol/L, a calcium to magnesium ratio of 4:1, a sodium to potassium ratio of 10:1 and thus a resulting initial pH value of 8.0 ± 0.2.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: 6-24 h old daphnids, from the laboartory's own culture (Bringrnann and Kühn, 1982)
- Feeding during test: no.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.4 mmol/L

pH:

8.0 ± 0.2

Dissolved oxygen:

> 4.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: two 50 mL beakers.
- Material, size, headspace, fill volume: glass, 50 mL, fill volume 20 mL.
- No. of organisms per vessel: 10. Loading amounted to one test animal per 2 ml test medium as 10 daphnids were placed in each test/control vessel, i.e. 20 animals per step.
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Ca/mg ratio: 4:1
- Culture medium different from test medium: not specified.

OTHER TEST CONDITIONS
- Adjustment of pH: no.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

VEHICLE CONTROL PERFORMED: no

Reference substance (positive control):

yes

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

7.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 10-12 mg/L

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

7.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 10-12 mg/L

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Remarks:

The test was considered as valid when fewer than 10% of the animals in the control solutions were unable to swim, when the pH value was not below 7.0 and the O2 value was not below 4.0 mg/L. The values reported were considered valid.

Conclusions:

The 48h-EC50 of the test item in Daphnia magna is 11 mg/L.

Executive summary:

An acute immobilisation test on Daphnia magna was performed in accordance with DIN 38412, Part II  (Daphnia short-time test). At least one concentration below and one above the EC50 value were tested in two replicates, each vessel (glass beaker) contained 10 daphnids. A positive control was run in parallel to assess the validity of the study. Based on the effects of the test item in Daphnia magna, the 48h-EC0 was found to be 7.3 mg/L, the EC100 20 mg/L, and the EC50, 11 mg/L.

Description of key information

Key study. Study according to DIN 38412, Part II  (Daphnia short-time test). The 48h-EC50 in daphnia of the test item is 11 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

11 mg/L

Additional information

An acute immobilisation test on Daphnia magna was performed in accordance with DIN 38412, Part II  (Daphnia short-time test). At least one concentration below and one above the EC50 value were tested in two replicates, each vessel (glass beaker) contained 10 daphnids. A positive control was run in parallel to assess the validity of the study. Based on the effects of the test item inDaphnia magna,the 48h-EC0 was found to be 7.3 mg/L, the EC100 20 mg/L, and the EC50, 11 mg/L.