polymeric zinc propylenebis(dithiocarbamate);propineb (ISO)

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-08-31 to 2011-11-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

Version / remarks:

adopted January 21, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

Soil was collected on 12 July 2011. The soil was removed to a depth of 20 cm as mixed sample. After collection, the soil was carefully dried at room temperature, passed through a 2 mm mesh sieve and then stored at a temperature of approx. 4 °C in containers under aerobic conditions in the dark.

A loamy sand soil was exposed for 70 days to 4.00 and 40.00 mg product/kg soil dry weight. Application rates were equivalent to 3 and 30 kg product/ha.

Determination of the nitrogen transformation (NO3-nitrogen production) in soil enriched with lucerne meal (concentration in soil 0.5 %). NH4-nitrogen, NO3- and NO2-nitrogen were determined using the Autoanalyzer II (BRAN+LUEBBE) at different sampling intervals (0, 7, 14, 28, 42, 56 and 70 days after treatment).

Test organisms (inoculum):

soil

Total exposure duration:

70 d

Test temperature:

18.9 °C - 21.5 °C in a climatic room

Moisture:

Water content of soil: 14.93 - 16.22 g/100 g soil d.w. (equivalent to 40.71 - 44.24 % of WHC)

Organic carbon content (% dry weight):

42.83

Nitrogen content (% dry weight):

2.74

Details on test conditions:

For calculation of the product requirements (mg/kg soil d.w.) a soil depth of 5 cm and a soil bulk density of 1.5 g dry weight/cm3 were assumed for conversion of soil volume to soil dry weight.

The test item was applied at an application rate of 3 kg/ha and a tenfold application rate of 30 kg/ha.
The nitrogen transformation was determined on day 0 (after approximately 3 hours) and at intervals of 7, 14, 28, 42, 56 and 70 days after application.

Nominal and measured concentrations:

Nominal concentration/application rate: 4.00 and 40.00 mg product/kg soil dw / 3 and 30 kg product/ha.

Reference substance (positive control):

yes

Remarks:

Dinoterb

Key result

Duration:

70 d

Dose descriptor:

other: nitrogen transformation

Effect conc.:

27.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: nitrogen transformation

Details on results:

Study was performed with the formulated product Propineb WG 70A W.

Propineb WG 70A W caused temporary stimulations of the daily nitrate rate at a test concentration of 4.00 mg/kg dry weight soil at the time intervals 7-14 and 42-56 days after application. Temporary stimulations of the daily nitrate rate were also observed at 40.00 mg/kg dry soil beginning at time interval 14-28 until time interval 42-56 days after application. Furthermore, a temporary inhibition of the daily nitrate rate could be observed at 40.00 mg/kg dry soil at time interval 0-7 days after application.
However, no adverse effects of Propineb WG 70A W on nitrogen transformation in soil could be observed at both tested concentration at the end of the test, 70 days after application (time interval 56-70 days after application).
Only negligible differences to control of -18.9% (test concentration 4.00 mg/kg dry soil) and +4.5% (test concentration 40.00 mg/kg dry soil) were measured at the end of the 70-day incubation period (time interval 56-70 days after application).

Results with reference substance (positive control):

In the most recent test, dated 05.01. - 07.02.2011, the toxic standard Dinoterb caused an effect of +42.0%, +68.1% and +92.3% (required > 25%) on the nitrogen transformation in a field soil at the tested concentrations of 6.80 mg, 16.00 mg and 27.00 mg Dinoterb per kg soil dry weight, respectively, 28 days after application and thus demonstrates the sensitivity of the test system.

Validity criteria fulfilled:

yes

Conclusions:

Propineb caused no adverse effects (difference to control < 25 %, on the soil nitrogen transformation (measured as NO3-N production) at the end of the 70-day incubation period. The study was performed in a field soil at concentrations up to 27.9 mg a.s./kg soil d.w..

Executive summary:

The purpose of this study was to determine the effects of the test item on the activity of soil microflora with regard to nitrogen transformation in a laboratory test. A loamy sand soil was exposed for 70 days to 2.79 and 27.9 mg a.s./kg soil dry weight. 

Propineb caused no adverse effects (difference to control <25 %, OECD 216) on the soil nitrogen transformation (measured as NO₃-N production) at the end of the 70-day incubation period. The study was performed in a field soil at concentrations up to 27.9 mg a.s./kg soil dry weight.

Description of key information

The purpose of this study was to determine the effects of the test item on the activity of soil microflora with regard to nitrogen transformation in a laboratory test. A loamy sand soil was exposed for 70 days to 2.79 and 27.9 mg a.s./kg soil dry weight. 

Propineb caused no adverse effects (difference to control <25%, OECD 216) on the soil nitrogen transformation (measured as NO₃-N production) at the end of the 70-day incubation period. The NOEC was determined to be 27.9 mg a.s/kg soil dry weight.

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:

27.9 mg/kg soil dw