L-Tyrosine, N-acetyl-3,5-diiodo-O-(4-methoxyphenyl)-, ethyl ester

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identi-cal. The keeping is performed similar to the method described in the OECD guideline, fol-lowing SOP 115 002 01 („Zucht und Hälterung von Daphnia magna STRAUS“), version 12 from 02. Feb. 2015.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

19.0 - 20.5 °C

pH:

7.7. - 7.8

Dissolved oxygen:

7.8 - 8.9 mg/L

Nominal and measured concentrations:

The measured concentrations are very similar at the beginning and end of the test (0.280 mg/L at test start, 0.235 mg/L at end of test). However, since these values differ by more than 20 % from the nominal value, the geometric mean of the two values is used to calcu-late the results (cf. OECD Guideline No. 202). Geometric mean is calculated by multiplica-tion of the n participating concentrations and taking the nth root.
On each sampling day, validity of calibration was controlled by measuring QC samples (5 mg/L). At test start (0h) the recovery rate of the QC 104.0% was taken into account (mean of 104.2%, 104.3%, 104.4% and 102.9%). At test end (48h) the recovery rate of the QC 95.6% was taken into account (mean of 95.6%, 93.3%, 96.9% and 96.4%).

Details on test conditions:

Medium renewal twice a week
Photo period 16/8 hours, using neon tubes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.257 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 0.257 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.257 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.257 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Conclusions:

Based on the test results the NOEC, 48 h can be stated to be >= 0.257 mg/L and the EC50, 48 h can be stated to be > 0.257 mg/L, respectively.
Due to the results of the study, the test material does not meet the criteria for a classification as acute aquatic toxic.

Executive summary:

The study was performed as a limit test at 100 mg/L nominal concentration. For the test concentration and the blank control, 20 daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised daphnia were counted.

None of the animals was immobilised in the blank control. There is only one daphnia immobilised in the treatment. Therefore, no statistical evaluation is performed.

Potassium dichromate K₂Cr₂O₇(CAS No. 7778-50-9) was used as positive controlin a current reference study to assure that the test conditions are reliable.

 

At the beginning and at the end of the test, the content of the test item in the test solutions was determined usingHPLC-UV-determination. The measured concentrations are very similar at the beginning and end of the test (0.280 mg/L at test start, 0.235 mg/L at end of test). However, since these values differ by more than 20 % from the nominal value, the geometric mean of the two values is used to calculate the results (cf. OECD Guideline No. 202).

No observations were made which might cause doubts concerning the validity of the study outcome. All validity criteria were met.

The result of the test is considered valid.

Description of key information

One study was performed according to OECD 202.

Based on the test results the NOEC, 48 h can be stated to be >= 0.257 mg/L and the EC50, 48 h can be stated to be > 0.257 mg/L, respectively.

Due to the results of the study, the test material does not meet the criteria for a classification as acute aquatic toxic.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.257 mg/L