Registration Dossier

Administrative data

Endpoint:
field studies
Type of information:
experimental study
Adequacy of study:
key study
Study period:
December 1996 - July 1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP compliant, non-guideline study. Available as unpublished report. Acceptable with restrictions as a field study is specific to the sites studied and weather conditions experienced during the study period.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Principles of method if other than guideline:
The cereal herbicide Topik 240 EC (active substance clodinafop-propargyl and safener cloquintocet-mexyl) was applied at the maximum recommended rate to two experimental sites located in central England. Soil and water samples were taken on both a routine and trigger event basis. Routine monitoring was carried out at least twice each month for the first six weeks and thereafter at the study directors discretion. Sampling was also triggered when rainfall exceeded certain criteria. Drain and surface samples were also collected when available following trigger events. Soil and water samples were analysed for the parent materials and known metabolites.
GLP compliance:
yes
Type of measurement:
Water and soil samples taken as part of the field study were analysed for the herbicide active ingredient, the safener and their respective metabolites. Only results for the safener and metabolites of the safener are reported here.
Media:
Water (soil water, surface runoff and drain water) and soil (one clay site, one sand site).

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): TOPIK 240 EC (containing Clodinafop propargyl (herbicide) and Cloquintocet-mexyl (safener))
- Lot/batch No.: 1634 CA DOF 4-96
- Composition of test material, percentage of components: 0.25 L/ha TOPIK 240EC is equivalent to 15 g/ha Cloquintocet-mexyl
- Storage condition of test material: not reported

Results and discussion

Any other information on results incl. tables

The concentration of (Cloquintocet-mexyl, CGA 185072) and its metabolite (CGA 153433) in all water samples were below the limit of detection (<0.05 µg/L).

The concentration of (Cloquintocet-mexyl, CGA 185072) and its metabolite (CGA 153433) was below the limit of detection (<0.005 mg/Kg) in all soil samples (sand and clay) below 5 cm depth at all sampling points. The concentration of (Cloquintocet-mexyl, CGA 185072) and its metabolite (CGA 153433) was below the limit of detection (<0.005 mg/Kg) in all clay soil samples from 1 month post treatment. The concentration of (Cloquintocet-mexyl, CGA 185072) was below the limit of detection (<0.005 mg/Kg) in all sand soil samples from 14 days post treatment. The concentration of its metabolite (CGA 153433) was below the limit of detection (<0.005 mg/Kg) in all sand soil samples from 6 months post treatment. Results are presented in table 1 and 2 below.

Table 1.  Concentration of CGA 185072 (mg/Kg) from soil samples over time

 

 

Concentration of CGA 185072 (mg/Kg) at days post treatment

Soil type

Replicate

0

1

3

7

14

Sand

A

0.017

0.017

0.005

0.007

<0.005

 

B

0.009

0.012

<0.005

0.006

<0.005

 

C

0.015

0.012

<0.005

0.008

<0.005

Clay

A

0.017

0.007

0.006

0.006

0.007

 

B

0.011

<0.005

0.007

<0.005

0.006

 

C

0.014

0.006

<0.005

<0.005

<0.005

Table 2 Concentration of CGA 153433 (mg/Kg) from soil samples over time

 

 

Concentration of CGA 153433 (mg/Kg) at days post treatment

Soil type

Replicate

0

1

3

7

14

~30

~90

Sand

A

0.007

<0.005

<0.005

0.011

0.006

0.012

0.006

 

B

<0.005

<0.005

0.006

0.011

0.011

0.010

0.006

 

C

<0.005

<0.005

<0.005

0.009

0.011

0.011

0.006

Clay

A

<0.005

<0.005

<0.005

<0.005

0.009

<0.005

<0.005

 

B

<0.005

<0.005

<0.005

0.005

0.006

<0.005

<0.005

 

C

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Applicant's summary and conclusion

Conclusions:
In a field study designed to monitor the concentrations of CGA 185072 and its metabolite CGA 153433 neither compound was detected above the limit of detection in water samples taken from day 0 to day 202 post treatment. Therefore, these compounds are considered not to have the potential to contaminate surface and groundwater.
Executive summary:

The concentrations of Cloquintocet-mexyl (CGA 185072) and its metabolite CGA 153433 were monitored in soil and water samples in a field study at a sandy and clay site. A single application was made in December 1997 at each site and samples were taken at predetermined times or when triggered by rainfall events. Neither CGA 185072 nor CGA 153433 were detected above the limit of detection in any water sample taken during the field trial. Both CGA 185072 and CGA 153433 were detected in the soil samples, but only in the samples from 0 - 5 cm depth. Concentrations had fallen to below the limit of detection after 1 month in the clay soil, and after 14 days and 6 months for the parent and metabolite respectively in the sand soil.