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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09-03-2009 - 13-05-2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test performed under GLP according guidelines, all quality criteria were met

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

not required

Vehicle:

no

Details on test solutions:

The tallow dipropylene triamine stock solution was prepared by stirring 0.1 g tallow dipropylene triamine in approximately 50 mL of deionized water and finally diluting it to 100 mL with deionized water. The tallow dipropylene triamine stock solution is a homogenous suspension.
pH stock solution = 9.4

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Secondary activated sludge was obtained (1st test: 10-03-2009 and 2nd test: 12-05-2009) (from the WWTP Nieuwgraaf in Duiven. The WWTP Duiven is an activated sludge plant treating predominantly domestic wastewater. Prior to use the activated sludge was homogenized with a syringe. The dry weight of the activated sludge in the incubation vessels was 1.6 g/L.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Remarks on exposure duration:

30 minutes exposure was tested first

Test temperature:

Temperature varied from 20.0 to 20.9°C.

pH:

The pH of the reaction mixtures after the incubation period ranged from 6.6 to 7.8.

Dissolved oxygen:

aerobic during test

Details on test conditions:

-The test was performed in 250 to 300 ml Erlenmeyers.
-The homogenized activated sludge was incubated in a shaking water bath (100 rpm, 20 °C) for 3 hours (The first test was performed withan incubation period of 30 minutes, because the test substance has a low solubility in water the incubation period used should be 3 hours = second test)
-Synthetic sewage was added to the activated sludge (1.6 ml on a total volume of 50 ml).
Synthetic sewage contained per liter: 16 g peptone
11 g meat extract
3 g urea
0.7 g NaCl
0.4 g CaCl2.2H2O
0.2 g MgSO4.7H2O
2.8 g K2HPO4
-Different concentrations (spaced by a factor two) of test compound and reference compound where added using stock solutions of respectively 1.0 g/l and 0.5 g/l.
-Tap-water was used to fill up the total test volume to 50 ml.
- The dry weight concentration of the activated sludge in the test was 1.6 g/l
-The tested concentrations of the reference compound 3,5-dichlorophenol where: 2.5 mg/l, 5.0 mg/l,10.0 mg/l, 20.0 mg/l and 40.0 mg/l
-The tested concentrations of tallow dipropylene triamine where: 20.3 mg/l, 40.6 mg/l, 81.2 mg/l, 162.4mg/l, 324.8 mg/l, 649.6 (mg/l)
-Controls without test substance (or reference compound) are measured at the beginning and at the end of the test
-The inhibitory effect of the test substance/reference compound is expressed as a percentage of the mean of the two control respiration rates.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

197 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% confidence limits of 74 and 2869 mg/l

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

595 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

Test conditions
The pH of the reaction mixtures after the incubation period ranged from 6.6 to 7.8. Temperature varied from 20.0 to 20.9°C. These conditions allowed respiration of the activated sludge used.

The EC50 of tallow dipropylene triamine for activated sludge after 30 minutes contact time is 595 mg/L. The EC10, EC20 and EC80 are 96, 180 and 1969 mg/L, respectively.
The EC50 of tallow dipropylene triamine for activated sludge after 3 hours contact time is 197 mg/L with 95% confidence limits of 74 and 2869 mg/L The EC10, EC20 and EC80 are 40, 69 and 564 mg/L, respectively.

Results with reference substance (positive control):

The EC50 of the reference compound were 8 and 11 mg/L at a contact time of 30 minutes and 3 hours, respectively. These EC50 values are within the prescribed range of 5 to 30 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The validity of the test is demonstrated by two criteria. First, the control respiration rates were within 15% of each other and second¬ly, the EC50 of the reference compound were 8 and 11 mg/L at a contact time of 30 minutes and 3 hours, respectively.

Conclusions:

Test performed under GLP according guidelines. The test is valid as shown by the EC50of the reference compound, 3,5-dichlorophenol (8 mg/L and 11 mg/L contact time 30 minutes and 3 hours respectively) and the control respiration rates which are within 15% of each other.
The EC50 of tallow dipropylene triamine for activated sludge after 30 minutes contact time is 595 mg/L. The EC10, EC20 and EC80 are 96, 180 and 1969 mg/L, respectively.
The EC50 of tallow dipropylene triamine for activated sludge after 3 hours contact time is 197 mg/L with 95% confidence limits of 74 and 2869 mg/L The EC10, EC20 and EC80 are 40, 69 and 564 mg/L, respectively.
Tallow dipropylene triamine is therefore considered not harmful to activated sludge.

The results of the 30 minutes incubation period should only be used as additional info. An incubation period of 3 hours is required to determine the toxicity of tallow dipropylene triamine to activated slugde, because of the low solubility of the test substance in water.

Executive summary:

In order to predict effects of chemicals in the environment and in biological waste water treatment plants, an activated sludge respiration inhibition test was performed. The toxicity to activated sludge was determined in accordance with OECD Test Guideline 209, and in compliance with the OECD principles of Good Laboratory Practice.

The test is valid as shown by the EC₅₀of the reference compound, 3,5-dichlorophenol (8 mg/L and 11 mg/L contact time 30 minutes and 3 hours respectively) and the control respiration rates which are within 15% of each other.

The toxicity of tallow dipropylene triamine to activated sludge was determined at contact times i.e. 0.5 and 3 hours, using various concentrations of the test substance. The inhibitory effect of tallow dipropylene triamine at a particular concentration is expressed as a percentage of the two controls. The EC₅₀of tallow dipropylene triamine for activated sludge after 30 minutes contact time is 595 mg/L. The EC₁₀, EC₂₀and EC₈₀are 96, 180 and 1969 mg/L, respectively.

The EC₅₀of tallow dipropylene triamine for activated sludge after 3 hours contact time is 197 mg/L with 95% confidence limits of 74 and 2869 mg/L The EC₁₀, EC₂₀and EC₈₀are 40, 69 and 564 mg/L, respectively.

Tallow dipropylene triamine is therefore considered not harmful to activated sludge.

Description of key information

The  3h-EC50 for microorganisms as observed in a three hour OECD 209 test is 197 mg/L and the EC10 is 40 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

197 mg/L

EC10 or NOEC for microorganisms:

40 mg/L