Amines, N-(3-aminopropyl)-N-(C16-18 and C18-unsatd. alkyl)trimethylenedi-

Toxicity to soil microorganisms

Administrative data

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine

EC Number:

219-145-8

EC Name:

N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine

Cas Number:

2372-82-9

Molecular formula:

C18H41N3

IUPAC Name:

N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine

Sampling and analysis

Analytical monitoring:

no

Test substrate

Vehicle:

no

Test organisms

Test organisms (inoculum):

soil

Study design

Total exposure duration:

28 d

Test conditions

Moisture:

1.5%

Details on test conditions:

- Following a preliminary range-finding test (nominal concentrations of 1.0, 10, 100 and 1,000 mg/kg), 18 soil micro-organism (Mixed population of soil microorganisms) test samples were exposed to a concentration of 1,000 mg/kg for a period of 28 d at a temperature of approximately 21°C.
- On Days 0, 7 and 28 triplicate control and six replicate test substance vessels were sacrificed for nitrate analysis.

Nominal and measured concentrations:

Nominal concentration: 1,000 mg a.i./kg soil dw

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

nitrate formation rate

Effect concentrations 2

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

nitrate formation rate

Details on results:

Range-finding study:
- The results showed no significant effect on nitrogen transformation activity.
- The absorbance values obtained for the 1,000 mg a.i./kg soil dw test concentration on day 0 were significantly higher than those obtained for the control an 1, 10 and 100 mg a.i./kg soil dw test concentrations. The reason for this could not be determined from the data however, as the results of the analyses conducted on day 28 confirmed that the test substance exhibited no adverse effect on the nitrogen transformation rate, it was considered that these relatively high results did not affect the outcome. Based on this result a single test concentration of 1,000 mg a.i./kg soil dw was selected for the definitive test.

Definitive study:
- The 28-d EC50 was estimated to be > 1,000 mg a.i./kg soil dw, where EC50 is the test concentration that reduced soil nitrogen transformation activity by 50 %.
- The test substance vessels were shown to have higher nitrate concentration than the control vessels on days 7 and 14 of the test. This increase in nitrate concentration was also observed in the range-finding test. The test substance was known to adsorb to soil/sediment and data provided by the Sponsor indicated that the test substance was readily biodegradable. It was therefore considered likely that under the experimental conditions employed in this study the test substance would adsorb to the soil with small amounts being present in the soil moisture. The small amount of test substance present in the soil moisture would then be available for biodegradation by the soil micro-organisms present. In the presence of a readily degradable carbon source available for growth and respiration, the numbers of soil micro-organisms present would increase at a faster rate than that in the control vessels which in turn would lead to an increase in the nitrogen transformation rate of the added respiratory substrate (powdered Lucerne-grass-green-meal).
- As the increase in nitrate concentrations in the test substance group could have only been due to an increase in the nitrogen transformation rate it was considered that the test substance exhibited no adverse effect on the nitrogen transformation rate and therefore the "No Observed Effect Concentration" (NOEC) was 1,000 mg a.i./kg soil dw. Further, it was considered unnecessary and unrealistic to test at concentrations in excess of 1,000 mg a.i./kg soil dw.

Reported statistics and error estimates:

- Statistical analysis of the nitrate concentration values was carried out for the control and test substance group using a Student’s t-test. The test substance group was shown to have significantly higher nitrate concentrations than the control group (P = 0.05).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, there was no significant effect of the test substance on the nitrogen transformation activity of soil microorganisms and therefore the 28 days EC50 value was estimated to be >1000 mg a.i./kg soil dw and the corresponding NOEC was 1000 mg a.i./kg soil dw.

Executive summary:

A study was conducted to determine the effect of the test substance on the nitrogen transformation activity of soil microorganisms according to the OECD Guideline 216, in compliance with GLP. Following a preliminary range-finding test (nominal concentrations of 1, 10, 100 and 1000 mg a.i./kg soil dw), 18 soil micro-organism (mixed population of soil microorganisms) test samples were exposed to a concentration of 1000 mg a.i./kg soil dw for a period of 28 d at a temperature of approximately 21°C. On Days 0, 7 and 28, triplicate control and six replicate test substance vessels were extracted for nitrate analysis. The test vessels were shown to have higher nitrate concentration than the control vessels on Days 7 and 14 of the test. Under the study conditions, there was no significant effect of the test substance on the nitrogen transformation activity of soil microorganisms and therefore the 28 d EC50 value was estimated to be >1000 mg a.i./kg soil dw and the corresponding NOEC was 1000 mg a.i./kg soil dw (Mead, 2004).