N-(2-nitrophenyl)phosphoric triamide

Biodegradation in soil

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-07-21 - 2006-09-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Radiolabelling:

no

Oxygen conditions:

aerobic

Soil classification:

DIN 19863 (Deutsche Industrie-Norm)

Soil no.:

#1

Soil type:

sand

% Org. C:

1.15

pH:

6

CEC:

7 meq/100 g soil d.w.

Soil no.:

#2

Soil type:

loamy sand

% Org. C:

2.33

pH:

5.7

CEC:

11 meq/100 g soil d.w.

Soil no.:

#3

Soil type:

loamy sand

% Org. C:

1.02

pH:

5.8

CEC:

9 meq/100 g soil d.w.

Details on soil characteristics:

The soils of different characteristics were sampled on/at:
• LUFA 2.1: October 11, 2005 (batch no.: F2.14105, SGS INSTITUT FRESENIUS GmbH identification: 010/5358087), depth of soil collection was down to 25 cm), Germany, Rheinland- Pfalz, Dudenhofen, Am Hanhofer Weg links, Nr. 3336/58, location of soil collection of no agricultural use, agricultural plant protection products and organic fertilizers not used for the sampling year and 4 former years.
Soil type (DIN/USDA): sand
• LUFA 2.2: October 24, 2005 (batch no.: F2.24305, SGS INSTITUT FRESENIUS GmbH identification: 010/5358088), depth of soil collection was down to 25 cm), Germany, Rheinland- Pfalz, Hanhofen, Großer Striet, Nr. 585, meadow, agricultural plant protection products and organic fertilizers not used for the sampling year and 4 former years.
Soil type (DIN/USDA): loamy sand
• LUFA 2.3: October 13, 2005 (batch no.: F2.34105, SGS INSTITUT FRESENIUS GmbH identification: 010/5358089), depth of soil collection was down to 25 cm), Germany, Rheinland- Pfalz, Offenbach, Im Bildgarten Nr. 586, fallow soil and pumpkin, agricultural plant protection products not used for the sampling year and 2 former years.
Soil type (DIN/USDA): loamy sand

Soil No.:

#1

Duration:

29 d

Soil No.:

#2

Duration:

29 d

Soil No.:

#3

Duration:

29 d

Soil No.:

#1

Initial conc.:

0.15 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#2

Initial conc.:

0.15 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#3

Initial conc.:

0.15 mg/kg soil d.w.

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Key result

Soil No.:

#1

DT50:

5.3 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20 °C

Key result

Soil No.:

#2

DT50:

3.9 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20 °C

Key result

Soil No.:

#3

DT50:

8.6 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20 °C

Transformation products:

yes

No.:

#1

Evaporation of parent compound:

not measured

Volatile metabolites:

not measured

Residues:

not measured

Conclusions:

The DT-50 values of N-(2-nitrophenyl)phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 5.3, 3.9 and 8.6 days. The DT-90 values of N-(2-mtrophenyl)-phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 17.7, 13.0 and 28.6 days.

Executive summary:

Aerobic Soil Degradation of N-(2-nitrophenyl)phosphoricacid triamide

N-(2-nitrophenyl)phosphoricacid triamide was tested in aerobic soil on the basis of OECD/OCDE Guideline no.307 for the testing of chemicals, adopted April 24, 2002. The study was performed in the laboratory using analytical grade N-(2-nitrophenyl)phosphoricacid triamide (purity of 99 % minimum). The degradation of N-(2-nitrophenyl)phosphoricacid triamide was investigated under aerobic conditions at 20 °C. Three German soils of different characteristics were used for the experiment (LUFA 2.1 - sand, LUFA 2.2 - loamy sand and LUFA 2.3 - loamy sand). The test concentration of 0.15 mg/kg dry soil was based on a penetration depth of the test item in the soil of 10 cm, a soil bulk density of 1 g/cm3 and on a total use of 150 g a.s./ha/year. The soil systems were acclimatized under a dynamic atmosphere of air to maintain aerobic conditions. The test period (two series) consisted of sampling intervals at times zero time, 1, 3, 7, 10, 14, 15, 22 and 29 days after incubation. The recoveries of N-(2-nitrophenyl)phosphoncacid triamide for the initial time specimens ranged from 84 to 95 % of the applied test item. One major degradation product of N-(2-nitrophenyl)phosphoricacid triamide was produced under aerobic conditions. 2-Nitroaniline reached maximum values of approximately 50 % in terms of the available compound (day-10 to day-15). For the description of the disappearance time of N-(2-nitrophenyl)phosphoricacid triamide, a 1st order kinetic was chosen. N-(2-nitrophenyl)phosphoricacid triamide degraded fastly in the soil test systems. The DT-50 values of N-(2-nitrophenyl)phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 5.3, 3.9 and 8.6 days. The DT-90 values of N-(2-mtrophenyl)-phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 17.7, 13.0 and 28.6 days.

Description of key information

OECD 307 guideline study, GLP

N-(2-nitrophenyl)phosphoricacid triamide was tested in aerobic soil on the basis of OECD/OCDE Guideline no.307 for the testing of chemicals, adopted April 24, 2002. The study was performed in the

laboratory using analytical grade N-(2-nitrophenyl)phosphoricacid triamide (purity of 99 % minimum). The degradation of N-(2-nitrophenyl)phosphoricacid triamide was investigated under aerobic conditions at 20 °C. Three German soils of different characteristics were used for the experiment (LUFA 2.1 - sand, LUFA 2.2 - loamy sand and LUFA 2.3 - loamy sand). The test concentration of 0.15 mg/kg dry soil was based on a penetration depth of the test item in the soil of 10 cm, a soil bulk density of 1 g/cm3 and on a total use of 150 g a.s./ha/year. The soil systems were acclimatized under a dynamic atmosphere of air to maintain aerobic conditions. The test period (two series) consisted of sampling intervals at times zero time, 1, 3, 7, 10, 14, 15, 22 and 29 days after incubation. The recoveries of N-(2 -nitrophenyl)phosphoncacid triamide for the initial time specimens ranged from 84 to 95 % of the applied test item. One major degradation product of N-(2-nitrophenyl)phosphoricacid triamide was produced under aerobic conditions. 2-Nitroaniline reached maximum values of approximately 50 % in terms of the available compound (day-10 to day-15). For the description of the disappearance time of N-(2 -nitrophenyl)phosphoricacid triamide, a 1st order kinetic was chosen. N-(2-nitrophenyl)phosphoricacid triamide degraded fastly in the soil test systems. The DT-50 values of N-(2-nitrophenyl)phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 5.3, 3.9 and 8.6 days. The DT-90 values of N-(2 -nitrophenyl)-phosphoricacid triamide in the LUFA 2.1, LUFA 2.2 and LUFA 2.3 were 17.7, 13.0 and 28.6 days.

Key value for chemical safety assessment

Half-life in soil:

8.6 d

at the temperature of:

20 °C