Nonanamide, N,N-dimethyl-

Endpoint summary

Description of key information

Toxicity to soil Macroorganisms

Under the conditions of this study, Genagen PA did not induce earthworm mortalities or pathological symptoms or changes in the behaviour of adult earthworms at any of the test item concentrations. There were no statistically significant differences in earthworm body weights in any test item concentrations compared to the control. After a further four weeks, the reproduction rate (average number of juveniles produced) was 67 in the control and ranged from 24 to 60 in the test item treatment replicates. There was no statistically significant difference in earthworm reproduction in the treatment rates 0.78 to 6.25 mg/kg SDW compared to the control. However, at the test item concentrations 12.5 to 100 mg/kg SDW the earthworm reproduction was statistically significantly reduced. The NOEC concerning mortality and biomass was determined to be ≥ 100 mg/kg SDW. The NOEC concerning reproduction was determined to be 6.25 mg/kg SDW. The EC20/50 – values for reproduction were determined.
All validity criteria recommended by the test guidelines were fulfilled.

 

Toxicity to soil Microorganisms

After 7 and 14 days of exposure to Genagen PA, no significant inhibition of the microbial nitrate transformation was observed for the test item concentrations 62.5 and 125 mg/kg soil dry weight. For the test item concentrations 250, 500 and 1000 mg/kg soil dry weight, negative nitrate formation rate were determined, due to low nitrate contents.
After 28 days of exposure, no significant inhibition of the microbial nitrate transformation was observed for the test item concentrations 62.5, 125 and 250 mg/kg soil dry weight. For the test item concentrations 500 and 1000 mg/kg soil dry weight, negative nitrate formation rate were determined.

For calculation of the ECx-values, the inhibition was set as 100 % for concentrations with negative nitrate-N formation rates.

After 7 days of exposure the EC10-, EC25- and EC50-values for inhibition of the nitrate-N formation rate were 130, 137 and 151 mg/kg soil dry weight, respectively.

After 14 days of exposure the EC10-, EC25- and EC50-values for inhibition of the nitrate-N formation rate were 162, 173 and 192 mg/kg soil dry weight, respectively.
 
After 28 days of exposure the EC10-value for inhibition of the nitrate-N formation rate in soil was 268 mg/kg soil dry weight, the EC25-value was 284 mg/kg soil dry weight and the EC50-value was 311 mg/kg soil dry weight.

The corresponding no-observed effect concentration (NOEC) was 125 mg Genagen PA/ kg soil dry weight on day 7 and 14 and 250 mg Genagen PA/kg soil dry weight on day 28. The LOEC was determined to be 250 mg Genagen PA/kg soil dry weight after 7 and 14 days and 500 mg Genagen PA/ kg soil dry weight after 28 days of exposure.