Fatty acids, tall-oil, reaction products with 2-[(2-aminoethyl)amino]ethanol

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:

July 2015-August 2015

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)

Qualifier:

according to guideline

Guideline:

EU Method C.21 (Soil Microorganisms: Nitrogen Transformation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

The test item was applied using the carrier quartz sand. 765.0 / 1353.8 / 2597.4 / 4594.4 / 8561.1 mg of test item were used to spike the quartz sand for the respective treatments (850 / 1580 / 2920 / 5400 / 10000 mg/kg dry soil). The spiked quartz sand was then mixed with the soil.
At the start of the test, 8.4 g quartz sand (corresponding to 10 g per 1 kg dry test soil) was added to the mixture vessel. The required amount of test item was added. For the blank control, quartz sand without test item was used. Then, 900 g of test soil and the required amount of organic substrate of 4.2 g (corresponding to 5 g/kg dry soil) was added and mixed with the quartz sand. Afterwards 55 mL of deionised water used for adjustment of the water content of the soil was added to each test vessel and mixed carefully (corresponding to a water holding capacity between 40 - 60 %). The amount of organic substrate corresponded to the recommended value in the guideline (5 g substrate per 1000 g dry weight of used test soil).

Test organisms (inoculum):

soil

Total exposure duration:

28 d

Test temperature:

20.3 - 22.0 °C

Moisture:

Mean water content in % (wet soil): 12.20 - 13.03
Water holding capacity: 40-60%

Details on test conditions:

Test vessel: glass preserving jars, nominal volume 1 L
Blank control: 3 vessels, each containing 300 g soil and acetone spiked quartz sand
Replicates: 3 vessels, each containing 300 g soil with acetone and test item spiked quartz sand

Nominal and measured concentrations:

nominal concentrations: 850 / 1580 / 2920 / 5400 / 10000 mg/kg dry soil

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 580 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

nitrate formation rate

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

2 242 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

nitrate formation rate

Duration:

28 d

Dose descriptor:

other: EC20

Effect conc.:

2 666 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

nitrate formation rate

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

3 700 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

nitrate formation rate

Inhibition/Production

The inhibition resp. production values were calculated by comparing the value of the treatment with the respective mean value of all controls (100%).

Production of Nitrate

The nitrate content of the replicates was measured at day 0 and day 28 of the experiment.

The nitrate formation of the treatments after 28 days compared to the control is stated in the table below.

Concentration in mg/kg dry matter Inhibition of nitrate production in % compared to blank control  850  -4.46  1580  -3.42  2920  24.83  5400  83.13  10000  91.78

  Negative inhibition implies a boost of nitrate production compared to the blank control.

Assessment

Calculation of results was performed with the help of validated software. The estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.1.

28d EC₅₀ : 3713 mg/kg

95% confidence interval: 3230 - 4260 mg/kg

NOEC: 1580 mg/kg

Validity criteria fulfilled:

yes

Executive summary:

The nitrogen transformation activity of soil after treatment with 400112 was determined according to OECD 216. One valid experiment was performed.

The study was performed using 5 concentrations (850/ 1580/ 2920/ 5400/ 10000 mg/kg) of 400112. Sieved soil was exposed to the test item for 28 days. Quartz sand was used as carrier. The soil pH was not adjusted.

After 0 days and 28 days test duration, the nitrate content of the soil of each treatment was determined. A blank control was tested.

Three concentrations showed inhibition of Nitrate production compared to the control. The resulting calculated 28d EC₅₀ value was 3713 mg/kg. The NOEC value was 1580 mg/kg.

The relative standard deviation between the replicates of the blank control was 1.3%, indicating the small difference between the replicates. Therefore the validity criterion was met and the result of the test can be considered valid.

No observations were made which might cause doubts concerning the validity of the study outcome.

Description of key information

The nitrogen transformation activity of soil after treatment with 400112 was determined according to OECD 216. One valid experiment was performed.

The study was performed using 5 concentrations (850/ 1580/ 2920/ 5400/ 10000 mg/kg) of 400112. Sieved soil was exposed to the test item for 28 days. Quartz sand was used as carrier. The soil pH was not adjusted.

After 0 days and 28 days test duration, the nitrate content of the soil of each treatment was determined. A blank control was tested.

Three concentrations showed inhibition of Nitrate production compared to the control. The resulting calculated 28d EC₅₀value was 3700 mg/kg. The NOEC value was 1580 mg/kg.

The relative standard deviation between the replicates of the blank control was 1.3 %, indicating the small difference between the replicates. Therefore the validity criterion was met and the result of the test can be considered valid.

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:

1 580 mg/kg soil dw