3',4',5'-trifluorobiphenyl-2-amine

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

GLP compliance:

yes

Test type:

laboratory

Test material

Test material information

Constituent 1

Radiolabelling:

yes

Study design

Oxygen conditions:

aerobic

Soil classification:

DIN 19863 (Deutsche Industrie-Norm)

Soil properties

Soil no.:

#1

Soil type:

loamy sand

% Clay:

11.2

% Silt:

27.2

% Sand:

61.5

% Org. C:

1.23

pH:

7.9

CEC:

12.2

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: Limburger Hof Bruch West, Germany
- Pesticide use history at the collection site: none (2005 -2009)
- Soil preparation:
- the soil was kept at room temperature for one day to allow sieving.
- the soil was passed through a 2 mm sieve
- remoistened to approximately 8-12% soil moisture (g H2O/100 g dry weight)
- The time period between sampling the soil and the application of the test item was less than 3 months

Duration of test (contact time)

Soil No.:

#1

Duration:

30 d

Initial test substance concentration

Soil No.:

#1

Initial conc.:

0.2 g/kg soil d.w.

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Experimental conditions

Soil No.:

#1

Humidity:

40% of the maximum water holding capacity

Details on experimental conditions:

EXPERIMENTAL DESIGN
Pre-incubation of soil:
- Three days prior to the application of the 1 4C-labeled test item, the soil was transferred to the laboratory and adjusted to 40% of the maximum water holding capacity
(MWHC).

Treatment:
- The pre-incubated soil was treated at a nominal concentration of 0.2 mg 14C-CAS 915416-45-4 per kg dry soil.
- After addition of the test item, the soil was slowly stirred with a hand-mixer for at least
10 minutes to homogeneously distribute the test item.
- Uniform distribution of the test item was later proved by combusting and analyzing five aliquots of about 0.5-0.6 g of the treated soil.
- after stirring, soil portions of 200.0 g dry soil equivalents were filled into 20 test vessels. – Number of replicates: 2
- one additional vessel with roughly 200 g dry soil was used to check the homogeneous distribution of the test item in the soil

Incubation:
- Aeration: Incubator was purged with moistened air
- Details of traps for volatiles: sequence of three adsorption traps filled with (1) 50 ml 0.5mol/L NaOH, (2) 50 ml 0.5mol/L H2SO4 and (3) 50 ml ethylene glycol
Sampling:
- Sampling intervals: after 0, 1, 2, 4, 7, 10, 14, 21, 30 days (termination day at which the radioactivity had decreased to values < 15% TAR
- Number of replicates at each sampling day: 2

Results and discussion

Material (mass) balance

Soil No.:

#1

% Recovery:

98.4

Remarks on result:

other: range 94.0 - 100.9%

Half-life / dissipation time of parent compound

Soil No.:

#1

DT50:

<= 4 d

Type:

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

Transformation products:

not measured

Details on transformation products:

The results of the present study indicate that the degradation of CAS 915416-45-4 in aerobic soil proceeds primarily via formation of bound residues and to a lesser extent via mineralization to CO2.

Details on results:

- ERR (extractable radioactivity): decreased rapidly from an average of 93.7% TAR at day 0 to down to 14.3% TAR at the end of the study after 30 days of incubation
- NER (non-extractable radioactive residues): Were formed in high amounts within a very short time. Already on day 0, immediately after soil treatment, average amounts of 6.3% TAR were observed. Bound residues quickly increased to 53.5% TAR after 4 days and further on to a maximum of 78.3% TAR by the end of the study.
- Volatiles: none, except CO2
- Mineralization: Moderate mineralization occurred during the study with C02 amounts reaching in total 6.2% TAR after 30 days of incubation. This shows that, basically, the biphenyl ring of CAS 915416-45-4 in principal is completely biodegradable.