cis-4-[3-(p-tert-butylphenyl)-2-methylpropyl]-2,6-dimethylmorpholine

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:

30.04. - 27.05.2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

BASF 421 F (Reg.No 108406, Fenpropimorph) batch No. N104, analysed purity: 93.2 % (tolerance +/- 1.0 %)

Analytical monitoring:

yes

Details on sampling:

As stated in OECD Guideline 216, an agriculturally utilised soil was selected.
The soil was removed to a depth of 20 cm as mixed sample.

Sampling scheme: 0, 7, 14 and 28 days after treatment.

Details on preparation and application of test substrate:

The soil was carefully dried at room temperature, passed through a 2 mm mesh sieve and then stored at a temperature of approx. 4 °C in containers under aerobic conditions in the dark.
Before application, the soil was adapted to test conditions.

Test organisms (inoculum):

soil

Total exposure duration:

28 d

Test temperature:

20.0 - 21.1 °C

Organic carbon content (% dry weight):

1.38

Nitrogen content (% dry weight):

0.15

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): Glass flasks, in the dark
- Amount of soil: 150 g soil d.w. per test vessel
- No. of replicates per concentration: 3
- No. of replicates per control: 3


SOIL INCUBATION
- Method: series of individual subsamples

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographical reference of sampling site (latitude, longitude): 12.694435960°; 51-403774567
- History of site: Wassergut Canitz, Saxony, Germany
- Treatments with pesticides: none since 1990
- Treatments with fertilizers: none since 2003
- Accidental contamination:
- Other: Soil removal: 05.03.2013
- Depth of sampling: 20 cm

- Soil texture
- % sand: 54.3
- % silt: 35.4
- % clay: 10.3
- Soil taxonomic classification: sandy loam
- Soil classification system: USDA
- pH (in water): 6.5
- Maximum water holding capacity (in % dry weigth): 45 % of maximum water holding capacity
- measured water content: 17.14 - 17.84 g/100 g dry soil
- Cation exchange capacity (cmol/kg soil): 8.9
- Pretreatment/ storage of soil: the soil was carefully dried at room temperature, passed through a 2 mm mesh sieve and then stored at a temperature of approx. 4 °C in containers under aerobic conditions in the dark. Before application, the soil was adapted to test conditions.
- Initial microbial biomass as % of total organic C: 2.51


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Effects on the NO3-nitrogen production 0, 7, 14 and 28 days after application.

Nominal and measured concentrations:

Control, 1.2 mg and 12 mg fenpropimorph/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

Dinoterb (purity: 98.0% ±0.5 analysed); the reference item was tested in a separate study at rates of 6.80, 16.00 and 27.00 mg/kg

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

12 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

nitrate formation rate

Remarks:

soil nitrogen transformation measured as NO3-N production

Details on results:

No differences greater than 25 % in the nitrogen transformation were found for the tested concentrations of fenpropimorph at the end of the 28-day incubation period (time interval 0-28) in comparison to the respective control.

The coefficients of variation during the experiment were within the demanded limit (control < 15%).

Results with reference substance (positive control):

In the most recent study, dated 04.01.-01.02.2013, the toxic standart dinoterb caused effects of +33.7% and +42.6% (required > 26%) on the nitrogen transformation at the tested concentrations of 16.00 mg and 27.00 mg/kg soil dry weight, respectively, 28 days after application and thus demonstrates the sensitivity of the test system.

Reported statistics and error estimates:

descriptive statistics

Time Interval (days)	Control	1.2 mg fenpropimorph/kg soil d.w.		12 mg fenpropimorph/kg soil d.w.
	NO3-N in mg/kg soil d.w. ^1)	NO3-N in mg/kg soil d.w. ^1)	% deviation from control	NO3-N in mg/kg soil d.w. ^1)	% deviation from control
0-7	25.27	22.9	-9.4	21.9	-13.3
0-14	33.7	32.87	-2.5	32.63	-3.2
0-28	45.3	44.7	-1.3	43.83	-3.2

The calculations were performend with unrounded values

¹⁾ measured values sampling day ''x'' - measured values sampling day 0, mean of 3 replicates

 

Validity criteria fulfilled:

yes

Remarks:

The coefficients of variation in the control were maximum 9.0 % and thus fulfilled the demanded range (control < 15%).

Conclusions:

Exposure of fenpropimroph in a field soil up to test concentration of 12 mg/kg soil dry weight caused no adverse effects (deviation from control < 25 %, OECD 216) on the soil nitrogen transformation (measured as NO3-N production) at the end of the 28-day incubation period (time interval 0-28).

Reference 2

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 217 (Soil Microorganisms: Carbon Transformation Test)

GLP compliance:

yes

Specific details on test material used for the study:

BASF 421 F (Reg.No 108406, Fenpropimorph) batch No. N104, analysed purity: 93.2 % (tolerance +/- 1.0 %)

Analytical monitoring:

yes

Details on sampling:

As stated in OECD Guideline 217, an agriculturally utilised soil was selected.
The soil was removed to a depth of 20 cm as mixed sample.

Sampling scheme: 0, 7, 14 and 28 days after treatment.

Details on preparation and application of test substrate:

The soil was carefully dried at room temperature, passed through a 2 mm mesh sieve and then stored at a temperature of approx. 4 °C in containers under aerobic conditions in the dark.
Before application, the soil was adapted to test conditions.

Test organisms (inoculum):

soil

Total exposure duration:

28 d

Test temperature:

20.0 - 21.1 °C

Organic carbon content (% dry weight):

1.38

Nitrogen content (% dry weight):

0.15

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): Glass flasks, in the dark
- Amount of soil: 150 g soil d.w. per test vessel
- No. of replicates per concentration: 3
- No. of replicates per control: 3


SOIL INCUBATION
- Method: series of individual subsamples

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographical reference of sampling site (latitude, longitude): 12.694435960° east; 51.403774567° north
- History of site: Wassergut Canitz, Saxony, Germany
- Treatments with pesticides: none since 1990
- Treatments with fertilizers: none since 2003
- Other: Soil removal: 05.03.2013
- Depth of sampling: 20 cm

- Soil texture
- % sand: 54.3
- % silt: 35.4
- % clay: 10.3
- Soil taxonomic classification: sandy loam
- Soil classification system: USDA
- pH (in water): 6.5
- Maximum water holding capacity (in % dry weigth): 45 % of maximum water holding capacity
- measured water content: 17.14 - 17.84 g/100 g dry soil
- Cation exchange capacity (cmol/kg soil): 8.9
- Pretreatment/ storage of soil: the soil was carefully dried at room temperature, passed through a 2 mm mesh sieve and then stored at a temperature of approx. 4 °C in containers under aerobic conditions in the dark. Before application, the soil was adapted to test conditions.
- Initial microbial biomass as % of total organic C: 2.51


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Effects on O2 consumption 0, 7, 14 and 28 days after application application.

Nominal and measured concentrations:

Control, 1.2 mg and 12 mg fenpropimorph/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

Dinoterb (purity: 98.0% ±0.5 analysed); the reference item was tested in a separate study at rates of 6.80, 16.00 and 27.00 mg/kg

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

12 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

respiration rate

Remarks:

soil carbon transformation measured as oxygen consumption

Details on results:

No differences greater than 25 % in O2 consumption were found for the tested concentrations of fenpropimorph at the end of the 28-day incubation period in comparison to the respective control.
The coefficients of variation during the experiment were within the demanded limit ( control < 15 % ).

Results with reference substance (positive control):

In the most recent study, dated 04.01.-01.02.2013, the toxic standart dinoterb caused effects of -39.3% and -45.2% (required > 25%) on the nitrogen transformation at the tested concentrations of 16.00 mg and 27.00 mg/kg soil dry weight, respectively, 28 days after application and thus demonstrates the sensitivity of the test system.

Reported statistics and error estimates:

descriptive statistics

Treatment group	Control		1.2 mg fenpropimorph/kg soil d.w.			12 mg fenpropimorph/kg soil d.w.
Days after application	O^2 consumption [mg/kg soil d.w. /h]	CV [%]	O^2 consumption [mg/kg soil d.w. /h]	CV [%]	Deviation from control [%]^1)	O^2 consumption [mg/kg soil d.w. /h]	CV [%]	Deviation from control [%]^1)
0	13	1.8	13	1.7	±0	12.78	1.1	-1.7
7	12.76	1	13.05	1.5	2.3	12.54	0.9	-1.7
14	11.69	0.4	11.72	0.8	0.3	11.73	0.3	0.3
28	10.76	0.6	10.88	1.3	1.1	10.9	2.7	1.3

 

The calculations were performend with unrounded values.

CV [%] = Coefficient of Variation

¹⁾ based on O² consumption; - = inhibition; + = stimulation

 

Validity criteria fulfilled:

yes

Remarks:

The coefficients of variation in the control were maximum 1.8 % and thus fulfilled the demanded range (control < 15%).

Conclusions:

Exposure of fenpropimorph in a field soil up to a test concentration of 12 mg/kg soil dry weight caused no adverse effects (deviation from control < 25 %, OECD 217) on the soil carbon transformation (measured as oxygen consumption) at the end of the 28-day incubation period.

Description of key information

Exposure of fenpropimroph in a field soil up to test concentration of 12 mg/kg soil dry weight caused no adverse effects (deviation from control < 25 %, OECD 216/ 217) on neither the soil nitrogen transformation (measured as NO₃-N production) nor the soil carbon transformation (measured as oxygen consumption) at the end of the 28-day incubation period (time interval 0-28).

 

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:

12 mg/kg soil dw

Additional information

In two studies on the toxicity of fenpropimorph-acid, the main metabolite of fenpropimorph, in soil had been tested on physiological functions of soil micro-organisms (laboratory studies). All studies were conducted according to GLP and different OECD guidelines (OECD 216/217). The test species was biologically active agricultural soil: loamy sand soil. No effect up to 0.222 mg/kg soil dw or 2.216 mg/kg dw was caused by fenpropimorph metabolite fenpropimorph-acid on neither the soil nitrogen transformation (measured as NO₃-N production) nor carbon transformation.

In study 1 (Koelzer, 2004/1014971) the carbon-transformation in soil was determined after addition of glucose. The test item soil was treated with the two following concentrations and compared to a non-treated soil: 0.222 mg fenpropimorph-acid/kg dry soil (corresponding to 0.75 kg a.s./ha) and 2.216 mg fenpropimorph-acid/kg (corresponding to 7.5 kg a.s./ha). Test concentrations related to a soil depth of 5 cm and a soil density of 1.5 g/cm³. The test soil was sampled at day 0, 7, 14 and 28 after treatment, sub-samples were withdrawn from the bulk batches and subjected to measurement. An OxiTop system was used to measure the O₂-consumption over a period of 24 hours at different sampling intervals. Based on the results of this study in accordance with OECD guideline 217, fenpropimorph-acid caused no short-term and long-term effects on carbon transformation in a field soil at concentrations of up to 2.216 mg fenpropimorph-acid per kg dry soil.

 

In study 2 (Koelzer, 2004/1014972) N-transformation (NO₃-nitrogen production) in soil was determined after enriching with lucerne meal (concentration in soil 0.5%). The test item soil was treated with the two following concentrations and compared to a non-treated soil: 0.222 mg fenpropimorph-acid/kg dry soil (corresponding to 0.75 kg a.s./ha) and 2.216 mg fenpropimorph-acid/kg (corresponding to 7.5 kg a.s./ha). Test concentrations related to a soil depth of 5 cm and a soil density of 1.5 g/cm³. The test soil was sampled at day 0, 7, 14 and 28 after treatment, sub-samples were withdrawn from the bulk batches and subjected to measurement. NH₄-nitrogen formed from organically bound nitrogen and NO₃-nitrogen from the nitrification process was determined by using calibrated ion-selective electrodes and an Orion expandable ionanalyzer EA 940, respectively. Based on the results of this study in accordance with OECD guideline 217, fenpropimorph-acid caused no short-term and long-term effects on carbon transformation in a field soil at concentrations of up to 2.216 mg fenpropimorph-acid per kg dry soil.

The results are summarized in table 1 below.

Table 1: Summary of effects of fenpropimorph-acid (BF 421-2) on soil micro-organisms

Test system/ Soil type	Application rate [mg/kg]	Result [%] deviation from control 1)	Reference
N-transformation
Loamy sand soil	0.222; 2.216	14.3; 14.2	Kölzer, 2004/1014972
C-transformation
Loamy sand soil	0.222; 2.216	-4.33; -5.89	Kölzer, 2004/1014971

1)            - = inhibition; + = stimulation