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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the nominal 3 h EC50 for respiration inhibition in microorganisms was determined to be 18 mg/L.

Executive summary:

A study was conducted to determine effect of the test substance on respiration inhibition in microorganisms according to OECD Guideline 209, in compliance with GLP. In this study, activated sludge from predominantly domestic sewage was used. Under the study conditions, the nominal 3 h EC50 for respiration inhibition in microorganisms was determined to be 18 mg/L (Bell, 1996).

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From February 12, 2002 to February 13, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

- The test substance and 3.5-dichlorophenol (reference substance) were added to the incubation vessels using stock solutions both of 0.5 g/L (minor deviation of the study plan).
- The stock solution of 3.5-dichlorophenol was prepared by dissolving 0.05 g 3.5 dichlorophenol in 1 mL of 1 M NaOH. Then diluting this to approximately 30 mL with deionized water, adding under stirring 0.5 M H2SO4 to the point of incipient precipitation and finally diluting the mixture to 100 mL with deionized water.
- The test substance stock solution was prepared by trembling in the ultrasonic bath 0.05 g the test substance in 80 mL of deionized water and finally diluting it to 100 mL with deionized water.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Initial biomass concentration: Secondary activated sludge was obtained from the WWTP in Arhem Zuid. The WWTP Arnhem Zuid is an activated sludge plant treating predominantly domestic waste water. Prior to use the activated sludge was homogenized with a syringe. The dry weight of the activated sludge in the incubation vessels was 1.0 g/L. Prior to use the activated sludge was homogenized with a syringe.
- The activated sludge with test substances was incubated in a shaking bath (100 rpm/min) for 30 minutes (contact time).

- The synthetic sewage feed was made by dissolving the following amounts of substances in 200 mL of deionized water: 3.2 g peptone, 2.2 g meat extract, 0.6 g urea, 0.14 g NaCl, 0.06 g CaCl2., 0.04 g MgSO4.7H2O, 0.56 g K2HPO4.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test temperature:

20°C

pH:

The pH of the reaction mixtures after the incubation period ranged from 7.3 to 7.5

Nominal and measured concentrations:

Nominal concentrations: 0, 6.64, 13.27, 26.54, 53.09 and 106.18 mg/L

Details on test conditions:

- The test was performed in 200 mL Erlenmeyers. The homogenized activated sludge with the test substance was incubated in a shaking water bath (100 rpm, 20°C) for 30 minutes.
- The respiration rates of the activated sludge were measured in a Biological Oxygen Moni­tor YSI 5300 (Yellow Springs Instruments). The BOM consisted of a thermostated vessel with a magnetic stirrer and an oxygen electrode. The electrode to measure the oxygen depletion tightly closed the vessel.
- The volume of the vessel was 10 mL and the temperature in the vessel was 20°C. The temperature was measured with a Keithley digital thermometer.
- The pH was measured using a Consort pH meter (Salm en , Breukelen, The Netherlands).
- The dry weight of the inoculum was determined by filtrating 100 mL of the activated sludge over a preweighed 12 mm Schleicher and Schüll filter. This filter was dried for 1.5 h at 104°C and weighed after cooling. Dry weight was calculated by subtracting the weighed filters.

OBSERVATIONS:
- In this test, the respiration rate of activated sludge fed with a standard amount of synthetic sewage was measured.
- The respiration rate of the same activated sludge in the presence of various concentrations of the test substance under otherwise identical conditions was also measured.
- The inhibitory effect of the test substance at a particular concentration was expressed as a percentage of the mean respiration rates of the controls
- Parameters observed included: Respiration rates of the activated sludge, inhibition percentages.

Reference substance (positive control):

yes

Remarks:

3.5-Dichlorophenol (p.a. quality 97% Lot no 02611ES-020) at 2.58, 5.15, 10.30, 20.60 mg/L

Key result

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

42.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: (95% CL of 27.9 and 77.8 mg/L); calculated values

Duration:

30 min

Dose descriptor:

other: EC80

Effect conc.:

65.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: calculated values

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

27.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: calculated values

Key result

Duration:

30 min

Dose descriptor:

NOEC

Effect conc.:

13.27 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

- The toxicity of the test substance to activated sludge was determined by measuring the respiration rate after a contact time of 30 minutes at various concentrations of the test substance. The inhibitory effect of the test substance at a particular concentration was expressed as a percentage of the two controls.
- Respiration rates of the activated sludge, inhibition percentages and pH at various concentrations of the test substance are given below:

Concentration Activity Inhibition pH
mg/L mg O2/min.L %

Control 2.8 - 7.3
Control 2.5 - 7.3
6.64 3.8 0 7.3
13.27 3.3 0 7.4
26.54 1.5 42 7.5
53.09 0.5 82 7.5
106.18 0.2 91 7.5

From the results EC values were calculated. The EC50 of the test substance for activated sludge is 42.2 mg/L with 95% confidence limits of 27.9 and 77.8 mg/L. The EC20 and EC80 were 27.3 and 65.1 mg/L, respectively. The NOEC was 13.27 mg/L.

Results with reference substance (positive control):

- 3.5-Dichlorophenol (p.a. quality 97 % Lot no 02611ES-020) used as a reference substance in the activated sludge respiration inhibition test was purchased from Aldrich Chemie, Brussel, Belgium.
- Respiration rates of the activated sludge, inhibition percentages, and pH at various concentrations of 3,5-dichlorophenol are given below:

Concentration Activity Inhibition pH
mg/L mg O2/min.L %

Control 2.8 - 7.4
Control 2.8 - 7.3
2.58 2.7 5 7.5
5.15 2.2 20 7.5
10.30 1.3 53 7.5
20.60 0.9 69 7.5

The EC50 (30 min) of the reference substance was estimated to be within 5-30 mg/L.

Reported statistics and error estimates:

In order to calculate the inhibitory effect of a test substance at a particular concentration, the respiration rate was expressed as a percentage of the mean of two controls of the respiration rate:

(1 - 2Rs / (Rc1 + Rc2)) x 100 = percentage inhibition

Rs = oxygen-consumption rate at tested concentration of test substance.
Rc = oxygen-consumption rate of controls.

The EC values were computed from the best-fitted line (least square method) through the points given by the probit of the percentage inhibition and the logarithm of the concentration of the substance. All computations were performed with the program TOXCALCTM on a personal computer.

All validity criteria were met:

- The control respiration rates were within 15% of each other;

- The EC50 of the reference compound was 12 mg/L which is within the prescribed range; 

- The pH of the reaction mixtures after the incubation period ranged from 7.3 to 7.5.

- Temperature was 20°C.

These conditions allowed respiration of the activated sludge used.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 30 min EC20, EC50, EC80 and NOEC values of the test substance were determined to be 27, 42, 65 and 13.27 mg/L, respectively.

Executive summary:

A study was conducted to determine the respiration inhibitory effect of the test substance to activated sludge according to OECD Guideline 209 and EU Method C.11, in compliance with GLP. Activated sIudge from domestic sewage was exposed to 0, 6.64, 13.27, 26.54, 53.09, 106.18 mg/L nominal concentrations of the test substance for 30 min followed by analysis for oxygen consumption rate or the respiration rate. The inhibitory effect of the test substance at a particular concentration was expressed as a percentage of the mean respiration rates of the controls. 3,5-dichlorophenol was used as reference substance at concentrations of 0, 2.58, 5.15, 10.30, 20.60 mg/L. Under the study conditions, the nominal 30 min EC20, EC50, EC80 and NOEC values of the test substance were determined to be 27, 42, 65 and 13.27 mg/L, respectively. The 30 min EC50 of the reference substance was estimated to be within 5-30 mg/L and all the validity criteria were met (Geerts, 2002).

Key value for chemical safety assessment

EC50 for microorganisms:

18 mg/L

Additional information

A study was conducted to determine effect of the test substance on respiration inhibition in microorganisms according to OECD Guideline 209, in compliance with GLP. In this study, activated sludge from predominantly domestic sewage was used. Under the study conditions, the nominal 3 h EC50 for respiration inhibition in microorganisms was determined to be 18 mg/L (Bell, 1996).

A study was conducted to determine the respiration inhibitory effect of the test substance to activated sludge according to OECD Guideline 209 and EU Method C.11, in compliance with GLP. Activated sIudge from domestic sewage was exposed to 0, 6.64, 13.27, 26.54, 53.09, 106.18 mg/L nominal concentrations of the test substance for 30 min followed by analysis for oxygen consumption rate or the respiration rate. The inhibitory effect of the test substance at a particular concentration was expressed as a percentage of the mean respiration rates of the controls. 3,5-dichlorophenol was used as reference substance at concentrations of 0, 2.58, 5.15, 10.30, 20.60 mg/L. Under the study conditions, the nominal 30 min EC20, EC50, EC80 and NOEC values of the test substance were determined to be 27, 42, 65 and 13.27 mg/L, respectively. The 30 min EC50 of the reference substance was estimated to be within 5-30 mg/L and all the validity criteria were met (Geerts, 2002).