Fatty acids, C16-18 (even numbered), reaction products with diethylene triamine, di-Me sulfate quaternized

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Remarks:

Biodegradation in water: screening test, toxicity control is used to derive effect concentration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Version / remarks:

1992

Deviations:

no

Principles of method if other than guideline:

From biodegradation in water: screening test, toxicity control is used to derive effect concentration

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: Kläranlage, Sunthelle 6, 57392 Schmallenberg, Germany
- Preparation of inoculum for exposure: kept aerobic and filtered through a coarse filter paper.
- Storage length: until use in the test, at least 1 h
- Concentration of sludge: 1 mL/L

Test type:

other: aerobic

Water media type:

other: mineral medium

Limit test:

no

Total exposure duration:

28 d

Test temperature:

20 (± 1 °C)

Details on test conditions:

TEST CONDITIONS
- Composition of medium: ( a ) KH 2 PO 4 8.50 g/L
K2HPO4 21.75 g/L
Na2HPO4 26.64 g/L
NH4Cl 0.51 g/L
( b ) CaCl2 x 2H2O 36.41 g/L
( c ) MgSO4 x 7H2O 22.50 g/L
( d ) FeCl3 x 6H2O 0.25 g/L.
The mineral medium applied in the test contained 1 mL/L of the mineral stock solution a–d, respectively. The mineral medium was strongly aerated for 20 minutes and allowed to stand for 20 h at test temperature.
- Test temperature: 20 °C (± 1 °C)
- Aeration of dilution water: yes
- Continuous darkness: yes

SAMPLING
- Sampling frequency: day 3*, 6, 10*, 14, 21*, and 28 (* without toxicity control) using an O 2 electrode.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 16 vessels containing only inoculum
- Toxicity control: 8 vessels containing test item (40 mg/L), reference item (2 mg/L) and inoculum

STATISTICAL METHODS:
Theoretical Oxygen Demand (ThOD):
The Theoretical Oxygen Demand (ThOD) was calculated on the basis of the sum formula of the test and reference item considering complete nitrification.
Biochemical Oxygen Demand (BOD):
The Biochemical Oxygen Demand (BOD) was calculated on the basis of the test raw data by BOD [mg/mg] = mg O2 uptake corrected by blank per mg test item.
The percent degradation was calculated according to the following formula:
D t = [(C t –C b ) / ThOD] x 100
D t : degradation (%) at time t;
C t : mean oxygen consumption (mg/L) in the test suspension at time t;
C b : mean oxygen consumption (mg/L) in the blanks at time t;
ThOD: Theoretical oxygen demand of the test suspension (mg/L).

Reference substance (positive control):

yes

Remarks:

sodium benzoate

Key result

Duration:

14 d

Dose descriptor:

other: % degradation (O2 consumption)

Effect conc.:

26 other: %

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

inhibition of heterotrophic respiration

Remarks on result:

other: O2 consumption after 14 days

Details on results:

- Blank controls oxygen uptake rate: O2 consumption/ % degradation after 14 d 96.9% within the procedural control.

Results with reference substance (positive control):

The biodegradation of sodium benzoate was 87.4% after 28 days.

Validity criteria fulfilled:

not applicable

Conclusions:

In a study concucted according to OECD guideline 301D 1992, the toxicity of hydrogenated tallow/nortallow based IQAC to microorganisms was determined. The test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 40 mg/L.

Executive summary:

The toxicity of hydrogenated tallow/nortallow based IQAC to microorganisms was investigated during a ready biodegradation study according to EU Method C.4-D (2008) and OECD guideline 301D (1992), Closed Bottle Test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant.

Inoculum blank, procedural/functional control with the reference substance Sodium benzoate and a toxicity control with 20 and 40 mg/L test item and 2 mg/L reference item Sodium benzoate were performed.

The reference item degraded normally (87.4 % by within 28 days).

The biodegradation of the item mixture in the toxicity control was found to be 75.5 % after 14 days of incubation. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 40 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

Description of key information

- study conducted according to OECD guideline 301 D (Closed Bottle Test), domestic sewage treatment plant sludge was incubated with 40 mg/L test item and 2 mg/L reference item, after 14 days degradation was > 25%, thus the substance is not inhibitory.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

40 mg/L

Additional information

The biodegradation of hydrogenated tallow/nortallow based IQAC, aqueous dispersion (5% ) was investigated over a 28-day period in a Closed Bottle Test according to OECD guideline 301 D (1992). The test medium was inoculated with activated sludge from a sewage treatment plant mainly fed with municipal wastewater. The rate of degradation was monitored by measuring the oxygen consumption over the 28-d period.

The test item was tested with a concentration of 20 and 40 mg/L in duplicates, corresponding to a carbon content (ThOC) of 2.83 and 5.66 mg C/L in the test vessels.

Degradation is followed by analysis of dissolved oxygen over a 28-day period. The amount of oxygen taken up by the microbial population during biodegradation of the test item (corrected for uptake by blank inoculum, run in parallel) is expressed as a percentage of ThOD.

The 10 % level (beginning of biodegradation of the test item) was reached within an adaptation phase of 3 days for the procedural control. The percentage of degradation of the functional control reached the pass level of 60 % after 3 days.

The highest mean biodegradation rate of hydrogenated tallow/nortallow based IQAC aqueous dispersion (5 %) within the 28 days of incubation in the static test was found to be 6 % (day 6) in the assays with 20 mg/L and 3 % (day 21) in the assays with 40 mg/L. Thus, no biodegradation within a 10-day-window could be obtained. The biodegradation of the item mixture in the toxicity control was found to be 26 % after 14 days of incubation. Thus, the demanded threshold value of 25 % is exceeded and the test item hydrogenated tallow/nortallow based IQAC, aqueous dispersion (5 %) can be identified as non-toxic in a ready biodegradability test. The reference item sodium benzoate was degraded to 97 % within the first 14 days, which was the highest degradation rate found within the test duration. In conclusion, according to the guideline, the test item hydrogenated tallow/nortallow based IQAC aqueous dispersion (5 %) must be identified as not readily biodegradable under the chosen test conditions.