3,5-diiodothyronine

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)

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:

20.3 - 21.9 °C

pH:

7.8 - 8.0

Dissolved oxygen:

8.4 - 8.9 mg/L

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.:

>= 24.02 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 24.02 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 24.02 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 24.02 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Conclusions:

Based on the test results the NOEC, 48 h can be stated to be >= 24.02 mg/L and the EC50, 48 h can be stated to be > 24.02 mg/L, respectively.

Executive summary:

Two experiments were performed.

The first experiment was performed without analytical determination of the test item. Therefore, a second experiment was performed in the same way as the first experiment but including specific analytical measurement.

The study was performed using 1 concentration containing 100 mg/L (nominal). 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.

In both Experiments, the concentration showed no toxicity and none of the animals was immobilised in the blank control.

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

At the beginning and at the end of the second experiment, the content of the test item in the test solutions was determined using HPLC-UV. The measured concentration at the start of the test was 22 % of the nominal concentration and 26 % of the nominal concen-tration at the end of the test. Because the measured concentrations were not within ± 20 % cent of the nominal concentration, the determination of the biological results was based on the geometric mean of the measured concentration in the second experiment. This procedure is in agreement with the OECD guideline No. 202, see paragraph 23 on page 5.

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 >= 24.02 mg/L and the EC50, 48 h can be stated to be > 24.02 mg/L, respectively.

For the classification according to CLP only the EC50 value is relevant. Due to the low biodegradabily an EC value of 24.02 mg/L leads to a classification as chronic aquatic toxic 3.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

24.02 mg/L