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

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

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 211 (Daphnia magna Reproduction Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1300 (Daphnid Chronic 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: 100%

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Remarks:

Dilution water

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test conditions

Hardness:

140 to 148 mg/L as CaCO3

Test temperature:

19.1 to 20.8°C

pH:

8.2 to 8.6

Dissolved oxygen:

≥6.7 mg/L (≥ 74% of saturation)

Conductivity:

366 to 373 μS/cm

Nominal and measured concentrations:

Nominal: 0.63, 1.3, 2.5, 5.0, and 10 mg a.s./L
Measured: 0.59, 1.2, 2.4, 4.7, and 9.6 mg a.s./L

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

4.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: adult survival

Effect concentrations 2

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

9.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: adult survival

Effect concentrations 3

Key result

Duration:

21 d

Dose descriptor:

other: MATC

Effect conc.:

6.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: adult survival

Effect concentrations 4

Key result

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 9.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: adult immobility and reproduction

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

21-Day NOEC (Daphnia magna, adult survival): 4.7 mg a.s./L
21-Day LOEC (Daphnia magna, adult survival): 9.6 mg a.s./L
21-Day Calculated MATC (Daphnia magna, adult survival): 6.7 mg a.s./L
21-Day EC50 (Daphnia magna, Immobility): >9.6 mg a.s./L
21-Day EC50 (Daphnia magna, Reproduction): >9.6 mg a.s./L

Executive summary:

The effects of test substance on the survival, growth and reproduction of Daphnia magna was determined in an unaerated, semi-static, 21-day test. The test was conducted in accordance to the OECD Guideline for Testing of Chemicals 211, Daphnia magna Reproduction Test and U.S. Environmental Protection Agency Series 850- Ecological Effects Test Guidelines, OPPTS Guideline 850.1300. Treatments consisted of a dilution water control and five nominal concentrations of 0.63, 1.3, 2.5, 5.0 and 10 mg a.s./L. The corresponding mean, measured concentrations were 0.59, 1.2, 2.4, 4.7 and 9.6 mg a.s./L, respectively.

Survival in the 0.59, 1.2, 2.4, 4.7 and 9.6 mg a.s./L treatment groups was 70, 80, 70, 90 and 60%, respectively, at test termination. No statistically significant decreases in mean neonate production in any treatment groups in comparison to the negative control. A significant difference in dry weight was noted in the 4.7 mg a.s./L treatment group in comparison to the control (Dunnett’s test, p ≤0.05). However, it was not considered to be treatment related since no significant difference in dry weight was noted in the 9.6 mg a.s./L, the highest treatment level. The 21-day NOEC and LOEC values for Daphnia magna based on adult survival and mean, measured concentrations of the test substance were 4.7 and 9.6 mg a.s./L, respectively. The calculated MATC was 6.7 mg a.s./L.