(1-methylethylidene)di-4,1-phenylenetetraphenyl diphosphate

Toxicity to soil microorganisms

Administrative data

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-compliant OECD and EC guideline study, performed in recognized contract research organization, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.21 (Soil Microorganisms: Nitrogen Transformation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

425-220-8

EC Name:

-

Cas Number:

5945-33-5

Molecular formula:

C39H34O8P2

IUPAC Name:

4-(2-{4-[(diphenoxyphosphoryl)oxy]phenyl}propan-2-yl)phenyl diphenyl phosphate; 4-{2-[4-({[4-(2-{4-[(diphenoxyphosphoryl)oxy]phenyl}propan-2-yl)phenoxy](phenoxy)phosphoryl}oxy)phenyl]propan-2-yl}phenyl diphenyl phosphate

Sampling and analysis

Analytical monitoring:

not required

Test substrate

Vehicle:

yes

Details on preparation and application of test substrate:

AMENDMENT OF SOIL
- Type of organic substrate: powdered lucerne-green-grass meal

APPLICATION OF TEST SUBSTANCE TO SOIL
- Method: vehicle stock solution added to dry quartz sand, evaporation of vehicle, incorporation into soil bulk

VEHICLE:
- Chemical name of vehicle: acetone
- Evaporation of vehicle before use: yes

Test organisms

Test organisms (inoculum):

soil

Study design

Total exposure duration:

28 d

Test conditions

Test temperature:

21 ± 1 °C

Moisture:

40% of the water holding capacity (± 5%)

Details on test conditions:

TEST SYSTEM
- Testing facility: dark, temperature controlled room
- Test container (type, material, size): glass jars
- Amount of soil: 50 g dry weight per test container
- No. of replicates per concentration: 18 (6 per sampling date)
- No. of replicates per control: 9 (3 per sampling date)
- No. of replicates per vehicle control: 9 (3 per sampling date)

SOIL INCUBATION
- Method: series of individual subsamples

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Specification: soil type 2.3 (field fresh), LUFA Speyer, Germany
- Geographical reference of sampling site: Germany / Rheinland-Pfalz / Offenburg; ''Im Bildgarten'', No. 507
- History of site
- Vegetation cover: uncultivated in sampling year and 4 former years
- Treatments with pesticides or fertilizers: no pesticides and no organic fertilization in sampling year and 4 former years
- Depth of sampling: ca. 20 cm
- Soil texture
- % sand: 62 ± 4.2
- % silt: 29 ± 3.6
- % clay: 9 ±1.4
- Soil taxonomic classification: sandy loam
- Soil classification system: USDA
- pH (in water): 7.0
- Initial nitrate concentration for nitrogen transformation test (mg nitrate/kg dry weight): about 90 mg/kg (after addition of powdered lucerne-green-grass meal)
- Maximum water holding capacity (in % dry weigth): 35.1 ± 2.0
- Cation exchange capacity (meq/100 g): 9.0 ± 3.0
- Storage (condition, duration): approx. 4 °C for approx. 2.5 months
- Initial microbial biomass as % of total organic C: 1.2

DETAILS OF PREINCUBATION OF SOIL (if any): prior to use, the soil was acclimated at approx. 21 °C for two days, shielded from light

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): nitrate formation rate after 7 and 28 days of exposure

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 10, 100 and 1000 mg/kg dry soil equivalent
- Results used to determine the conditions for the definitive study: no significant effect on nitrogen transformation activity at all concentrations tested

Nominal and measured concentrations:

nominal: 1000 mg/kg soil (dry weight)

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

nitrate formation rate

Effect concentrations 2

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

nitrate formation rate

Effect concentrations 3

Duration:

28 d

Dose descriptor:

EC25

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

nitrate formation rate

Effect concentrations 4

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

nitrate formation rate

Reported statistics and error estimates:

Statistical analysis on the nitrate concentration values was performed using a Students t-test. All statistical analyses were performed using the SAS computer software package (SAS 1999 - 2001).

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable