clothianidin (ISO); (E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Feb - 18 Mar, 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

1987

Deviations:

no

Remarks:

According to the current OECD guideline: the test solution renewal should be 3 times a week (only once in the report).

GLP compliance:

yes (incl. QA statement)

Remarks:

Niedersächsisches Umweltministerium, delivered on 07 Jul, 1997

Analytical monitoring:

yes

Details on sampling:

All concentrations and control were analysed when freshly prepared on Friday and at the time of renewal on Monday and were made on a sample from the same solution.

Vehicle:

no

Details on test solutions:

Stock solution: 104.2 mg/L formulation = 100 mg/L active ingredient
Stock solution and dilutions were prepared with dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

Number:10 per concentration and control
Age: 2-24 hours old
Feeding: Every day with algae Scenedesmus subspicatus, 0.1 - 0.2 mg C/Daphnia/day

Test type:

semi-static

Water media type:

freshwater

Remarks:

B.P. ELENDT M4

Limit test:

no

Total exposure duration:

21 d

Hardness:

233 - 263 mg/L CaCO3

Test temperature:

19.1 - 20.8°C

pH:

7.73 - 8.62

Dissolved oxygen:

8.2 - 9.2 mg/L

Salinity:

Not applicable

Conductivity:

Not specified

Nominal and measured concentrations:

Nominal: 0.041 - 0.12 - 0.37 -1.1 - 3.3- 9.9 - 29.7 mg a.i./L
Measured ranged from 98% to 104%

Details on test conditions:

Culture method: In 2 L glass vessels with approximatively 1.0 L culture medium, at 21°C (temperatures of 20-25°C were tolerated), in an incubator, 16 h illumination.
Culture medium: B.P. ELENDT M4, according to Selenium Deficiency in Crustacea.
Feeding per culture medium: The broodstocks are cultured in 2 L glass vessels with ca. 20 daphnids each and are fed with algae Scenedesmus subspicatus and Chlorella vulgaris 5 x weekly.
The study organisms were acclimated to the dilution water 2 h before test start.
Photoperiod: 16/8 h light/dark cycle

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.12 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

5.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

parental

Details on results:

In the concentrations 9.9 and 29.7 mg/L aborted winter eggs were observed. In the other concentrations no winter eggs occured. Dead offspring was not recorded in any of the concentrations and the control.
All eggs, produced in controls and at the test concentrations 0.041 - 3.3 mg/L resulted in hatching of juveniles.
Regarding the first appearance of juveniles significant deviations were observed at the concentrations 9.9 and 29.7 mg/L compared with the control group.

Results with reference substance (positive control):

An acute immobilisation test was carried out with potassium dichromate as reference substance in 1998. The EC50 value of the reference substance at 1.40 mg/L after 24 h was within the validity range of 0.9 to 1.9 mg/L according to DIN 38412 L 11.

Please refer to "overall remark/ attached background material" field for result tables.

Table 1: Validity criteria for OECD 211

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality of the parent animals in the control (female Daphnia) does not exceed 20% at the end of the test.	0% in control	Yes
The mean number of living offspring produced per parent animal surviving at the end of the test is ≥ 60 in the control.	64.5 in control	Yes

Validity criteria fulfilled:

yes

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the NOEC and EC50 (21-day) for Daphnia magna were 0.12 and 5.7 a.s. mg/L, respectively.

Description of key information

From long-term key study, the 21-day NOEC for aquatic invertebrates exposed to the present test material was 0.12 mg a.s./L in freshwater.

From long-term supporting study, the 39-day NOEC for aquatic invertebrates exposed to the present test material was 9.7 µg a.s./L in saltwater.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

ca. 0.12 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

NOEC

Remarks:

supportive study

Effect concentration:

ca. 9.7 µg/L

Additional information

In the key study the long-term effects of the substance towards aquatic invertebrates were examined in a 21-day toxicity test withDaphnia magnaunder semi-static conditions (2000). The study was carried out according to GLP and OECD 211. Daphnia were exposed to nominal concentrations of 0.041, 0.12, 0.37, 1.1, 3.3, 9.9 and 29.7 mg a.s./L, alongside with a control. Based on this study, the 21d NOEC reproduction for aquatic invertebrates exposed to test substance in the freshwater was 0.12 mg a.s./L.

 

There is one additional study conducted withMysidopsis bahia, which was considered suitable for supporting purpose. In this study (2000), the long-term effects of test material toMysidopsis bahiawas determined in a 39-d flow-through test according to OPPTS 850.1350 guideline. Based on this study, the 39d NOEC for aquatic invertebrates exposed to the test substance in the saltwater was determined to be 9.7 µg a.s./L.