Registration Dossier

Diss Factsheets

Environmental fate & pathways

Biodegradation in soil

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
biodegradation in soil
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1993-02-12 to 1993-02-26
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was not conducted in compliance with GLP and no test guideline was followed; but no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.
Qualifier:
no guideline followed
Principles of method if other than guideline:
CR-39 monomer was tested for biodegradability in an aerobic fresh soil medium at a test concentration of 100 /µg/g. The CR-39 monomer soil biodegradation study was conducted in the dark at a temperature range of 25 +/- 1 °C. The study was terminated after 14 days. During the 14-day test period, all test systems (control, sterile and test) were maintained under aerobic conditions.
GLP compliance:
no
Test type:
laboratory
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not relevant
Radiolabelling:
no
Oxygen conditions:
aerobic
Soil classification:
not specified
Soil no.:
#1
Soil type:
other: Composite soil was prepared by combining soils BD-002, BD-003 and BD-004
pH:
7.28
Details on soil characteristics:
SOIL COLLECTION AND STORAGE
- Geographic location: Soils BD-002 and BD-003 were collected near Englewood, Missouri. Soil BD-004 was collected for ABC Laboratories' property in Columbia, Missouri.
- Pesticide use history at the collection site: Not given
- Collection procedures: Not given
- Sampling depth (cm): Not given
- Storage conditions: A composite soil was prepared by combining 150 g (dry weight) of soils BD-002, BD-003 and BD-004. The wet soil was allowed to air dry at ambient room temperature for approximately 6 hours. The soils were then mixed and sieved through a 2 mm standard testing sieve and placed in a labeled 1 gallon glass jar for storage.
- Storage length: Soils were collected at 1992-12-30 (72 days prior to test initiation).
- Soil preparation (e.g., 2 mm sieved; air dried etc.): The soils were then mixed and sieved through a 2 mm standard testing sieve


PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%): The field capacity of Soil-Mix I was determined to be 67.3 %. The pH of Soil-Mix I was determined to be 7.28.
- Bulk density (g/cm3): Not given
Soil No.:
#1
Duration:
14 d
Soil No.:
#1
Initial conc.:
100 mg/kg soil d.w.
Based on:
test mat.
Parameter followed for biodegradation estimation:
test mat. analysis
Soil No.:
#1
Temp.:
25 +/-1°C
Humidity:
50% of field capacity
Details on experimental conditions:
1. PRELIMINARY EXPERIMENTS:
Not performed

2. EXPERIMENTAL DESIGN
- Soil preincubation conditions (duration, temperature if applicable): The incubation tubes were placed in their respective metabolism vessels and placed in a Norlake 25 ± 1 °C environmental chamber. The vessels were continuously aerated with water saturated C02-free air.
- Soil condition: All 32 definitive soils were brought up to approximately 50 % field capacity with Milli-Q reagent water.
- Soil (g/replicate): A 10.0-g (dry weight) aliquot of Soil-Mix I was added to each of thirty-two 25 X 150 mm glass, screw top, Pyrex culture tubes.
- Control conditions, if used (present differences from other treatments, i.e., sterile/non-sterile, experimental conditions):
- No. of replication controls, if used: The soil samples were used for eight control soils, eight sterile soils, and sixteen test soils.
- No. of replication treatments: The eight sterile soils and sixteen test soils were dosed with 0.0926 µL of the 10.8 mg/mL CR-39 monomer standard using a 100-µL Hamilton syringe to achieve a 100 µg/g CR-39 monomer soil concentration.
- Test apparatus (Type/material/volume): 25 X 150 mm glass, screw top, Pyrex culture tubes
- Details of traps for CO2 and organic volatile, if any: Not given
- If no traps were used, is the system closed/open: Open
- Identity and concentration of co-solvent:


Test material application
- Volume of test solution used/treatment: The eight sterile soils and sixteen test soils were dosed with 0.0926 µL of the 10.8 mg/mL CR-39 monomer standard using a 100-µL Hamilton syringe to achieve a 100 µg/g CR-39 monomer soil concentration.
- Application method (e.g. applied on surface, homogeneous mixing etc.): application by 100-µL Hamilton syringe
- Is the co-solvent evaporated: The solvent (ether) was allowed to evaporate from all of the soils.


Any indication of the test material adsorbing to the walls of the test apparatus: None


Experimental conditions (in addition to defined fields)
- Moisture maintenance method: All 32 definitive soils were brought up to approximately 50 % field capacity with Milli-Q reagent water.
- Continuous darkness: No


Other details, if any: None


3. OXYGEN CONDITIONS (delete elements as appropriate)
- Methods used to create the an/aerobic conditions: The vessels were continuously aerated with water saturated C02-free air.
- Evidence that an/aerobic conditions were maintained during the experiment (e.g. redox potential): Not given


4. SUPPLEMENTARY EXPERIMENTS:


5. SAMPLING DETAILS
- Sampling intervals: Samples were taken for CR-39 monomer analysis at initiation and on days 3, 7, and 14. One control, one sterile, and two test incubation tubes were taken on each sample day.
- Sampling method for soil samples: Each soil sample was extracted with three 30-mL aliquots of methanol.
- Method of collection of CO2 and volatile organic compounds: Not relevant for this test procedure
- Sampling intervals/times for:
> Sterility check, if sterile controls are used: One control, one sterile, and two test incubation tubes were taken on each sample day.
- Other observations, if any: None
Soil No.:
#1
% Recovery:
97.2
Soil No.:
#1
% Degr.:
> 90
Parameter:
test mat. analysis
Sampling time:
3 d
Soil No.:
#1
DT50:
< 3 d
Type:
not specified
Temp.:
25 °C
Transformation products:
no
Details on transformation products:
No degradates were observed in the soil extracts.
Evaporation of parent compound:
not specified
Volatile metabolites:
not specified
Residues:
not specified
Details on results:
TEST CONDITIONS
- Aerobicity, moisture, temperature and other experimental conditions maintained throughout the study: Yes
- Anomalies or problems encountered (if yes): None

Results with reference substance:
Not relevant

A normal phase high performance liquid chromatography system was developed and validated for the quantitation of CR-39 monomer. The mean recovery for 10 ppm and 100 ppm spiked soils was 104% and 103%, respectively, during the method validation portion of this study. The mean recovery of CR-39 monomer in the day 0 test and sterile samples was 97.2%. At the 3-day sample point (and subsequent 7- and 14-day sample points), no CR-39 monomer was detected in any of the soil samples, indicating that CR-39 monomer had biologically degraded, chemically degraded, or volatilized to a level which was below the detection limit (10 ppm). Additionally, no degradates were observed in the soil extracts. Due to the disappearance of the test chemical in both the sterile and nonsterile (test) system, it is not possible to characterize the extent of biodegradation.

Conclusions:
At the 3-day sample point (and subsequent 7- and 14-day sample points), no CR-39 monomer was detected in any of the soil samples, indicating that CR-39 monomer had biologically degraded, chemically degraded, or volatilized to a level which was below the detection limit (10 ppm). Additionally, no degradates were observed in the soil extracts. Due to the disappearance of the test chemical in both the sterile and nonsterile (test) system, it is not possible to characterize the extent of biodegradation.
Executive summary:

CR-39 monomer was tested for biodegradability in an aerobic fresh soil medium at a test concentration of 100 µg/g. The CR-39 monomer soil biodegradation study was conducted in the dark at a temperature range of 25 +/- 1 °C. The study was terminated after 14 days. During the 14-day test period, all test systems (control, sterile and test) were maintained under aerobic conditions.

The test chemical, CR-39 Monomer, was biologically degraded, chemically degraded, or volatilized in soil at 25 ± 1 °C to a level which was below the analytical detection limit (10 ppm) within 3 days.

Description of key information

half life in soil < 3d at 25 ± 1°C

Key value for chemical safety assessment

Half-life in soil:
3 d
at the temperature of:
25 °C

Additional information

This endpoint is filled from data from one biodegradability test in soil (no guideline followed; Williams, 1993).

The test substance 'diallyl 2,2'-oxydiethyl dicarbonate' was biologically degraded, chemically degraded, or volatilized in soil at 25 ± 1 °C to a level which was below the analytical detection limit (10 ppm) within 3 days [half life in soil < 3d at 25 ± 1°C]. Additionally, no degradates were observed in the soil extracts. Due to the disappearance of the test substance in both the sterile and nonsterile (test) system, it was not possible to characterize the extent of biodegradation.