Registration Dossier

Administrative data

Endpoint:
toxicity to soil microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From November 03 2016 to December 05 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)
Deviations:
yes
Remarks:
Two deviations were observed during this study. The deviations are not critical and have no influence on the results of this study.
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Specific details on test material used for the study:
Purity/Concentration: >99% dry matter
Batch number: 160722014882 w/o solvent
Appearance: Beige waxy liquid
Storage conditions: Room temperature (15 - 25°C)

Sampling and analysis

Analytical monitoring:
not required

Test substrate

Vehicle:
yes
Details on preparation and application of test substrate:
According to the sponsor, the test item “D-GLUCOPYRANOSE, OLIGOMERS, XYLITYL GLYCOSIDES AND 1,4 ANHYDRO D-XYLITOL AND D-XYLITOL” is fully soluble in water and the deionized water was used as the carrier. The test item was directly added in the testing solutions and mixed with the soil.

Test organisms

Test organisms (inoculum):
soil

Study design

Total exposure duration:
28 d

Test conditions

Test temperature:
20 +/- 2°C
Moisture:
The moisture content of the samples was checked and adjusted two or three times a week in order to maintain the moisture content of soil within 40 - 60 ± 5 % of Water Holding Capacity (WHC).
In order to respect the recommendation, the moisture content of soil samples was calculated for the lower and the highest WHC interval:
0.3482*0.40*100 = 13.9% for 40% WHC
0.3482*0.60*100 = 20.9 % for 60% WHC
During the period of incubation (28 days), the moisture contents of soil samples were well within 13.9 % and 20.9% which corresponds to 40 to 60% WHC and were compliant to the guideline OECD 216.
Details on test conditions:
6*500 g of soil samples were amended with powdered Lucerne alfalfa mea, with a C/N ratio between 12/1 and 16/1 and placed in test containers with sufficient headspace, under aerobic conditions.
Five soil portions were mixed with the test item “D-GLUCOPYRANOSE, OLIGOMERS, XYLITYL GLYCOSIDES AND 1,4 ANHYDRO D-XYLITOL AND D-XYLITOL” at the five test concentrations and one soil portion, moistened with water (Control)
Nominal and measured concentrations:
As the test item was non agrochemicals, five concentrations were tested according the preliminary test, non GLP and in agreement with the sponsor, the nominal concentrations were as follow: 50 – 105 – 220 – 463 – 972 mg test item / kg dry soil.
Reference substance (positive control):
no

Results and discussion

Effect concentrations
Key result
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
>= 972 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
nitrate formation rate
Details on results:
The micro-organisms responsible of the formation of nitrate were not affected at any tested concentration.
No statistical difference (T-Test) was observed between the five concentrations with deviations from Control. Thus, no significant effect has been demonstrated after 28 days exposure with the test item
Reported statistics and error estimates:
The formed NO3-N in each treatment was compared with NO3-N in the control. A dose-response curve versus time was prepared. Statistical evaluation of the test results was performed with an ANOVA analysis at 5% significant level (Minitab 17, statistical software) and a NOEC was determined but no LOEC. The results did not permit to calculate a regression in order to determine an estimation of the ECx values.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
All the validity criteria were successful.
No adverse effects of the test item “D-GLUCOPYRANOSE, OLIGOMERS, XYLITYL GLYCOSIDES AND 1,4 ANHYDRO D-XYLITOL AND D-XYLITOL” on nitrogen transformation in soil was observed at any tested concentration (50, 105, 200, 463 and 972 mg/Kg soil dry weight) after 28 days of incubation. A NOEC value was determined as follows: NOEC = 972 mg/Kg soil dry weight.
Executive summary:

The aim of this study was to investigate long term potential effects after a single exposure of the test item “D-GLUCOPYRANOSE, OLIGOMERS, XYLITYL GLYCOSIDES AND 1,4 ANHYDRO D-XYLITOL AND D-XYLITOL” on Nitrogen transformation activity of soils microorganisms according to the OECD 216 guideline (January 21, 2000).

Sieved soil was amended with powdered Lucerne meal and either treated with the test item or left untreated (Control). As the test item was non agrochemicals, five concentrations were tested according the preliminary test, non GLP and in agreement with the sponsor, the concentrations were as follow: 50 – 105 – 220 – 463 – 972 mg test item / kg dry soil.

The untreated (control) and treated (50, 105, 220, 463 and 972 mg/Kg soil dry weight) samples were incubated in the dark at 20+/- 2°C. The moisture content of the samples was checked and adjusted two or three times a week. NO3-N content was determined in the control and treated soils at 0, 14 and 28 days after treatment by ionic chromatography.

The micro-organisms responsible of the formation of nitrate were not affected at any tested concentration. No statistical difference (T-Test) was observed between the five concentrations with deviations from control. Thus, no significant effect has been demonstrated after 28 days exposure with the test item.