ethametsulfuron-methyl (ISO); methyl 2-[(4-ethoxy-6-methylamino-1,3,5-triazin-2-yl)carbamoylsulfamoyl]benzoate

Long-term toxicity to fish

Administrative data

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1400 (Fish Early-life Stage Toxicity Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 002

Cas Number:

97780-06-8

Test material form:

solid

Details on test material:

Purity: 99.2%

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Remarks:

dimethylformamide

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

87 d

Test conditions

Hardness:

128 to 140 mg/L as CaCO3 (negative control) and 136 to 144 mg/L as CaCO3 (5.4 mg a.s./L)

Test temperature:

12 ± 1ºC

pH:

7.8 to 8.4

Dissolved oxygen:

≥ 6.8 mg/L (63% of saturation)

Conductivity:

351 to 403 μS/cm (negative control) and 354 to 397 μS/cm (5.4 mg a.s./L)

Nominal and measured concentrations:

Nominal: 0.38, 0.75, 1.5, 3.0, 6.0 mg a.s./L
Measured: 0.33, 0.70, 1.3, 2.8, 5.4 mg a.s./L

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

87 d

Dose descriptor:

NOEC

Effect conc.:

5.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: time to hatch, hatching success, time to swim-up, survival and growth

Remarks on result:

other: highest concentration tested

Effect concentrations 2

Key result

Duration:

87 d

Dose descriptor:

LOEC

Effect conc.:

> 5.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: time to hatch, hatching success, time to swim-up, survival and growth

Remarks on result:

other: highest concentration tested

Effect concentrations 3

Key result

Duration:

87 d

Dose descriptor:

other: MATC

Effect conc.:

> 5.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: time to hatch, hatching success, time to swim-up, survival and growth

Remarks on result:

other: highest concentration tested

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

87 d NOEC (Oncorhynchus mykiss): 5.4 mg a.s./L (time to hatch, hatching success, time to swim-up, survival and growth) (Highest concentration tested)
87 d LOEC and MATC (Oncorhynchus mykiss): >5.4 mg a.s./L (time to hatch, hatching success, time to swim-up, survival and growth) (Highest concentration tested)

Executive summary:

The effects of test substance on the early life stages (based on time to hatch, hatching success, time to swim-up, survival and growth) of rainbow trout (Oncorhynchus mykiss) were determined in an unaerated flowthrough system for 87 days. The test was conducted in based on to the OECD Guideline for Testing of Chemicals, 210 and U.S. Environmental Protection Agency Series 850 – Ecological Effects test Guidelines, OPPTS Guideline 850.1400. Treatments consisted of a dilution water control, solvent control (0.1 mL dimethylformamide/L) and five nominal concentrations of 0.38, 0.75, 1.5, 3.0 and 6.0 mg a.s./L. The corresponding mean, measured concentrations were 0.33, 0.70, 1.3, 2.8 and 5.4 mg a.s./L.

During the embryo incubation period, the embryos were observed daily and any dead embryos or embryos with fungus were counted and removed. Daily observations were made during the post-hatch exposure period to evaluate the numbers of individuals exhibiting clinical signs of toxicity or abnormal behaviour. Post-hatch growth of the rainbow trout was measured at the end of the test (study day 87, 60 days post-hatch).

There were no treatment-related effects on hatching success, time to hatch, time for larvae to swim-up, or post-hatch growth and survival. The NOEC, based on mean, measured test concentrations, and the time to hatch, hatching success, time to swim-up, survival and growth was 5.4 mg a.s./L. The LOEC and MATC were >5.4 mg a.s./L, the highest concentration tested.