Amines, N-(C18-unsatd. alkyl)trimethylenedi-, ethoxylated

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

22-02-2010 - 24-02-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The toxicity to microorganisms test result as observed for the tallow based product is read across to the Oleyl based product. The products differ only in their alkylchain distribution. Both tallow and Oleyl are natural fats for which the composition slightly changes over time due to changes in the environmental considitions.

The tallow alkyl fat which is used for the production of CAS no 1268344-02-0 are for 99 % straight chain alkyl fats

Commercial tallow alkyl fats have the following distribution:

C12 about 2 %
C14 about 4 %
C16 about 31 %
C18 about 65 %,
where 40 –50 % are unsaturated.

The oleyl fate which is used for the production of CAS no 1290049-56-7 are also straight chain fates

Commercial Oleylfats have the following distribution:

C12 1 %
C14 2 - 4 %
C16 and C16’ 12 - 14 %
C18, C18’ and C18’’ > 80 % (C18: 8 %, C18’cis: 46 %, C18’trans: 21 %, C18’’: 5 %)
C20 1 %
(a single prime indicates one double bond, a double prime indicates two double bonds):

When the water solubility of cationic surfactants based on tallow are compared to oleyl based cationic surfactants it is consistently the tallow product which has a sligthly lower water solubility and due to that also a slightly lower bioavailability. This lower bioavailability regularly results is slight differences in biodegradation rate and ecotoxicity. The substances are however difficult to test substances and the variation in the test results is especially in ecotoxicity testing frequently larger than the difference in bioavailability. It is therefore considered justified to use the tallow product test results for read across for the oleyl based product.

Reason / purpose for cross-reference:

read-across source

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 tris (2-hydroxyethyl) oleyl diaminopropane stock solution was prepared by stirring 0.43 g tris (2-hydroxyethyl) oleyl diaminopropane in 430 mL of deionized water. The tris (2-hydroxyethyl) oleyl diaminopropane stock solution was a homogenous suspension (very light turbidity).
pH stock solution = 8.8

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Unadapted secondary activated sludge was obtained (22-02-2010) 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
homogenized activated sludge was determined and subsequently concentrated by settlement to the required dry weight concentration. The dry
weight of the activated sludge in the incubation vessels was 1.7 g/L.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

Temperature varied from 20.2 to 21.0°C.

pH:

The pH of the reaction mixtures after the incubation period ranged from 6.9 to 7.2.

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 with various concentrations of the test
compound and synthetic sewage.
-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 1.7 g/l
-The tested concentrations of the reference compound 3,5-dichlorophenol where: 1.25, 2.5 mg/l, 5.1 mg/l,10.2 mg/l, 20.3 mg/l and 40.6 mg/l
-The tested concentrations of tris (2-hydroxyethyl) oleyl diaminopropane where: 10 mg/l, 20 mg/l, 40 mg/l, 80 mg/l and 160 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:

EC50

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: with 95% confidence limits of 20 and 1146 mg/L

Details on results:

Test conditions
The pH of the reaction mixtures after the incubation period ranged from 6.9 to 7.2. Temperature varied from 20.2 to 21.0 °C. These conditions allowed respiration of the activated sludge used.

Validity of the test
The validity of the test is demonstrated by two criteria. First, the control respiration rates were within 15% of each other and secondly, the EC50 of the reference compound was 8 mg/L which is within the prescribed range of 5 to 30 mg/L .

Activated sludge respiration inhibition test
The inhibitory effect of tris (2-hydroxyethyl) oleyl diaminopropane at a particular concentration is expressed as a percentage of the two controls.
From the results EC values were calculated.
The EC50 of tris (2-hydroxyethyl) oleyl diaminopropane for activated sludge after 3 hours contact time is 56 mg/L with 95% confidence limits of 20 and 1146 mg/L. The EC10, EC20 and EC80 are 14, 23 and 137 mg/L, respectively.

Results with reference substance (positive control):

The EC50 of the reference compound was 8 mg/L at a contact time of 3 hours, respectively. These EC50 values is 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 secondly, the EC50 of the reference compound was 8 mg/L which is within the prescribed range of 5 to 30 mg/L .

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
contact time 3 hours ) and the control respiration rates which are within 15% of each other.
The EC50 of tris (2-hydroxyethyl) oleyl diaminopropane for activated sludge after 3 hours contact time is 56 mg/L with 95% confidence limits of 20 and 1146 mg/L. The EC10, EC20 and EC80 are 14, 23 and 137 mg/L, respectively.
Tris (2-hydroxyethyl) oleyl diaminopropane is therefore considered harmful to activated sludge

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 the control respiration rates which are within 15% of each other.

The toxicity of tris (2-hydroxyethyl) oleyl diaminopropane to activated sludge was determined at a contact time of 3 hours, using various concentrations of the test substance. The inhibitory effect of tris (2-hydroxyethyl) oleyl diaminopropane at a particular concentration is expressed as a percentage of the two controls. The EC₅₀of tris (2-hydroxyethyl) oleyl diaminopropane for activated sludge after 3 hours contact time is 56 mg/L with 95% confidence limits of 20 and 1146 mg/L. The EC₁₀, EC₂₀and EC₈₀are 14, 23 and 137 mg/L, respectively.

Tris (2-hydroxyethyl) oleyl diaminopropane is therefore considered harmful to activated sludge.

Description of key information

Two studies on toxicity to microorganisms in sewage sludge treatment plants are available, both were performed according to OECD 209 and are considered to be reliable. The key study wuth an EC50 (3-h) of 56 mg/L was performed with the tallow based ethoxylated diamine. The supporting study was performed with a tallow based ethoxylated diamine and had an EC50 (3-h) of 70 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

56 mg/L

EC10 or NOEC for microorganisms:

14 mg/L