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

Endpoint summary

Description of key information

The substance was tested on different aquatic organisms, representing the three trophic levels: fish, invertebrates and algae; furthermore, testing on microorganisms also is available. With respect to fish, data are available for both freshwater and marine water.

The 96-hour LC50 for fish exposed to the present test material was > 117 mg a.s./L for L. macrochirus in freshwater.

The 96-hour LC50 for fish exposed to the present test material was > 100 mg a.s./L for C. variegatus in saltwater.

The 48-hour EC50 for aquatic invertebrates exposed to the present test material was 0.029 mg a.s./L for C. riparius in freshwater.

The 96-hour LC50 for aquatic invertebrates exposed to the present test material was 0.053 mg a.s./L for A. bahia in saltwater.

The 96-h ErC₅₀ for algae exposed to the present test material was > 100 mg a.s./L for N. pelliculosa in freshwater.

The 96-h ErC₅₀for algae exposed to the present test material was 37.8 mg a.s./L for S.costatum in saltwater.

The NOEC for early life stage of P. promelas was ≥ 20 mg a.s./L.

The 28-day EC10 for aquatic invertebrates exposed to the present test material was 0.4 µg a.s./L for C. riparius in freshwater.

The 39-day NOEC for aquatic invertebrates exposed to the present test material was 9.7 µg a.s./L for M. bahia in saltwater.

The 96-h NOEC for algae exposed to the present test material was 40 mg a.s./L for N. pelliculosa in freshwater.

The 96-h NOEC for algae exposed to the present test material was 6.4 mg a.s./L for S.costatum in saltwater.

The 3-hour EC50 for microorganisms exposed to the present test material was > 1000 mg /L.

Thus, the most sensitive values refer to the aquatic invertebrate, for both, the acute and the chronic aquatic toxicity.

Additional information

A short-term key toxicity study assessed the effects on fish, according to OECD 203 performed with the bluegill sunfish Lepomis macrochirus (M-031285-01-1; 96 h, freshwater). The acute effect value in fish was determined in with an LC₅₀(96h) of > 117 mg/L (mean measured).

The long-term effects of the substance towards fish were examined in a flow-through 33-day early-life stage toxicity test with Pimephales promelas according to OPPTS 850.140 (M-031516-01-1). A NOEC (33d) of ≥ 20 mg/L (mean measured) was determined as the derived chronic value.

 

Aquatic invertebrates were the most sensitive organisms when exposed to the test item. In an acute toxicity test on the freshwater invertebrate Chironomus riparius (M-0321142-01-2) , resulting in an EC₅₀(48 h) of 0.029 mg a.s./L.

The long-term effects of the substance towards Chironomus riparius were examined in a 28-day toxicity test with according to BBA-method (M-0118784-01-1). A EC10 (28d) of 0.4 µg/L (mean measured) was determined.

 

The toxicity of the substance to aquatic algae was investigated in a study performed according to OECD 201 with freshwater algae N. pelliculosa (M-421991-01-1). The 96-h ErC₅₀was > 100 mg/L (nominal). The NOEC (96 h) was determined to be 40 mg/L (nominal).

The effect of the substance on the respiration rate of microorganisms (activated sludge) was examined in a dose-response test at 1000 mg/L according to OECD 209 (M-021659-01-1). The EC₅₀(3 h) was determined to be > 1000 mg/L (nominal).

 

Additionally, the potential endocrine disrupter effects were assessed for fish and covered in the early life stage study.

A GLP-study dated 2000 is available to evaluate the test materials potential for endocrine activity with fish (M-031516-01-1). This study was conducted according to the OPPTS Guideline 890.1400. The fathead minnows (Pimephales promelas) were exposed under flow through conditions to mean measured concentrations of 1.2, 2.5, 5.5, 9.7 and 20 mg a.s./L, for 33 days. Since no obvious findings were noticed up to and at the híghest tested concentration of 20 mg a.s./L, the NOEC was ≥ 20 mg a.s./L.