Benzamide, N-[[4-[(cyclopropylamino)carbonyl]phenyl]sulfonyl]-2-methoxy-

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Sep - 13 Oct 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 217 (Soil Microorganisms: Carbon Transformation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

APPLICATION OF TEST SUBSTANCE TO SOIL
- Method: Sieved soil (2 mm) was treated with either 10 g ground quartz sand/kg dry weight soil (control) or a mixture of quartz sand and AE 0001789 tech. (AE 0001789 00 1C97 0005) (0.21 mg or 1.07 mg/kg dry weight soil). The samples were mixed with pulverized lucerne-grass-green meal (5 g/kg dry weight soil) and quartz sand in 3 liter polyethylene containers by rolling on a gyrowheel mixer (Elte 650, J. Engelsmann AG, Ludwigshafen, Germany) for 15 min at 50 rpm.

Test organisms (inoculum):

soil

Total exposure duration:

28 d

Test temperature:

20 ± 2 °C

Details on test conditions:

TEST SYSTEM
- Testing facility: Laboratory
- Test container (type, material, size): 500 mL brown glass bottles and these were closed with parafilm
- Amount of soil: 350 g dry weight
- No. of replicates per concentration: 3
- No. of replicates per control: 3


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographical reference of sampling site: The soil used is from Field plot F on the Bayer CropScience AG's experimental farm Laacherhof, Germany. The Laacherhof experimental farm is located at a latitude of 51 °4' north and a longitude of 6°55' east.
- History of site: experimental farm Laacherhof, Germany with grass, summer wheat, winter rye, winter barley, winter wheat
- Vegetation cover: Yes
- Treatments with pesticides or fertilizers: Plant protection chemicals have not been used on this field since 1981. The plot has been under grass and has not been treated with fertilizers since 1996
- Accidental contamination: No
- Depth of sampling: 0-20 cm
- Soil taxonomic classification: loamy sand
- Storage (condition, duration): It was passed through a 2 mm sieve and stored at 4 ± 2 °C until used (according to guideline)
- Initial microbial biomass as % of total organic C: 1.3

Nominal and measured concentrations:

In this study, the equivalents of 0 kg (Control), 0.16 kg and 0.8 kg of AE 0001789 tech./ha were added to samples of an agricultural soil (0, 0.21 and 1.07 mg/kg dry weight soil).

Reference substance (positive control):

yes

Remarks:

Sodium chloride

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 1.07 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate

Remarks on result:

other: (equivalent to 0.8 kg product/ha)

Conclusions:

During the 28-day tests, 0.16 kg AE 0001789 tech. / ha and the 5-fold overdose of the test item had no influence on carbon transformation after addition of glucose to a loamy sand.

Table 1: Validity criteria for OECD 217 (2000)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The variation between replicate control samples should be less than ± 15%.	The highest coefficient of variation (CV) between carbon dioxide concentration in replicate control samples was 5.5 %.	yes

 

Validity criteria fulfilled:

yes

Remarks:

See Table 1 in "Any other information on results incl. tables".

Reference 2

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Sep - 14 Oct 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

AMENDMENT OF SOIL
- Type of organic substrate:
Substrate: Lucerne-grass-green meal
Source of Substrate: Hoeveler Kraftfutter, 40764 Langenfeld
Content: 40.6 % Ctotal, 0.05 % Cinorg, 2.5 % N

APPLICATION OF TEST SUBSTANCE TO SOIL
- Method: Sieved soil (2 mm) was treated with either 10 g ground quartz sand/kg dry weight soil (control) or a mixture of quartz sand and AE 0001789 tech. (AE 0001789 00 1C97 0005) (0.21 mg or 1.07 mg/kg dry weight soil). The samples were mixed with pulverized lucerne-grass-green meal (5 g/kg dry weight soil) and quartz sand in 3 liter polyethylene containers by rolling on a gyrowheel mixer (Elte 650, J. Engelsmann AG, Ludwigshafen, Germany) for 15 min at 50 rpm.

Test organisms (inoculum):

soil

Total exposure duration:

28 d

Test temperature:

20 ± 2 °C

Details on test conditions:

TEST SYSTEM
- Testing facility: Laboratory
- Test container (type, material, size): brown glass bottles and these were closed with parafilm
- Amount of soil: 300 g dry weight
- No. of replicates per concentration: 3
- No. of replicates per control: 3


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographical reference of sampling site: The soil used is from Field plot F on the Bayer CropScience AG's experimental farm Laacherhof, Germany. The Laacherhof experimental farm is located at a latitude of 51 °4' north and a longitude of 6°55' east.
- History of site: experimental farm Laacherhof, Germany with grass, summer wheat, winter rye, winter barley, winter wheat
- Vegetation cover: Yes
- Treatments with pesticides or fertilizers: Plant protection chemicals have not been used on this field since 1981. The plot has been under grass and has not been treated with fertilizers since 1996
- Accidental contamination: No
- Depth of sampling: 0-20 cm
- Soil taxonomic classification: loamy sand
- Storage (condition, duration): It was passed through a 2 mm sieve and stored at 4 ± 2 °C until used (according to guideline)
- Initial microbial biomass as % of total organic C: 1.3

Nominal and measured concentrations:

In this study, the equivalents of 0 kg (Control), 0.16 kg and 0.8 kg of AE 0001789 tech./ha, corresponding to 0.21 mg and 1.07 mg AE 0001789 tech. (AE 0001789 00 1C97 0005)/kg dry weight soil, were added to samples of an agricultural soil.

Reference substance (positive control):

yes

Remarks:

Sodium chloride

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 1.07 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

nitrate formation rate

Remarks on result:

other: (equivalent to 0.8 kg product/ha)

During the 28-day test, in a soil amended with lucerne-grass-green-meal (5 g/kg), it was found that 0.21 mg AE 0001789 tech./kg dry weight soil (equivalent to 0.16 kg product/ha) and the 5-fold field rate of the compound had no influence on nitrogen transformation in a loamy sand. In none of the time intervals analysed during the 28 day exposure the difference in the daily nitrate-N rates exceeds the trigger value of 25 %.

Conclusions: During the 28-day test, the recommended field rate of AE 0001789 tech. and the 5-fold field rate of the compound had no influence on nitrogen transformation in a loamy sand soil amended with lucerne-grass-green meal.

Table 1: Validity criteria for OECD 216 (2000)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The variation of nitrate concentrations between replicate control samples should be less than ± 15%.	The variation of nitrate concentrations between replicate control samples should be less than≤10%.	yes

 

Validity criteria fulfilled:

yes

Remarks:

See Table 1 in "Any other information on results incl. tables".

Description of key information

NOEC (28 d): ≥1.07 mg/kg soil dw (nominal, soil microflora, OECD 216)

 

NOEC (28 d): ≥1.07 mg/kg soil dw (nominal, soil microflora, OECD 217)

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:

1.07 mg/kg soil dw

Additional information

Based on one carbon (M-261945-01-1) and one nitrogen (M-262722-01-1) transformation test which were conducted according to OECD 217 and OECD 216, it can be concluded that, the substance has no negative influence on the turnover of organic carbon and nitrogen in soil. During the 28-day tests, the recommended field rate of the substance (0.21 mg/kg soil dw) and the 5-fold rate of the compound (1.07 mg/kg soil dw) had no effects >25% on nitrogen transformation in a loamy sand soil amended with lucerne-grass-green meal or the carbon transformation after addition of glucose to a loamy sand compared to the controls.

Thus, no risk to soil microorganisms is to be expected from the use of the substance as a safener in a formulation under practical field conditions.