Fatty acids, C16-18 (even numbered), reaction products with tetraethylenepentamine, acetates (salts)

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

Study period:

February 07, 2005 - March 10, 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test) (1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) (1992)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test material: Fatty acids, C16-18, reaction products with tetraethylenepentamine, acetates (salts)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): ARA Ergolz ll, Fillinsdorf, Switzerland
The sludge was washed twice with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated.
Based on this ratio, calculated amounts of wet sludge were suspended in test water to obtain a concentration equivalent to 4 g (±10%) dry material per liter. During holding, the sludge was aerated at room temperature until use. Prior to use, the sludge was diluted with test water to a concentration of 1 g per liter (dry weight basis). Defined volumes of this diluted activated sludge were added to test water to obtain a final concentration of 30 mg dry material per liter.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

14 d

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

27.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: inhibition control in biodegradation test

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of C1618FA-TEPA-compound to microorganisms was investigated during a ready biodegradation study. The test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 27.1 mg/L.

Executive summary:

The toxicity of C1618FA-TEPA-compound (ca. 90% a.i.) to microorganisms was investigated during a ready biodegradation study according to EU Method C.4-C (1992) and OECD guideline 301 B (1992), CO2 evolution test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant. The biodegradation rate was determined by measurement of carbon dioxide evolution.

Inoculum blank, procedural/functional control with the reference substance Sodium benzoate and a toxicity control with 27.1 mg/L test item and 25.7 mg/L reference item Sodium benzoate were performed.

The reference item degraded normally (63% by within 14 days). By the end of the test, the reference item was degraded to an average of 72%.

At the end of the 28-day exposure period, the mean extent of biodegradation of the test item was 9%. No significant biodegradation of C16 18FA-TEPA-compound occurred under the test conditions within 28 days and the pass level for ready biodegradability of at least 60% degradation 10-day window within the 28-day period of the test was not reached.

The extent of biodegradation in the toxicity control showed a similar course over the 28-day exposure period when compared to the procedure control containing the reference item, only. Within 14 days of exposure, the extent of biodegradation was 35%. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 27.1 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

Description of key information

C1618FA-TEPA-compound had no inhibitory effects on activated sludge microorganisms at the tested concentration of 27.1 mg/L as determined during a ready biodegradation study according to EU Method C.4-C and OECD guideline 301 B.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

27.1 mg/L

Additional information

The toxicity of C16 18FA-TEPA-compound (ca. 90% a.i.) to microorganisms was investigated during a ready biodegradation study according to EU Method C.4-C (1992) and OECD guideline 301 B (1992), CO2 evolution test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant. The biodegradation rate was determined by measurement of carbon dioxide evolution.

Inoculum blank, procedural/functional control with the reference substance Sodium benzoate and a toxicity control with 27.1 mg/L test item and 25.7 mg/L reference item Sodium benzoate were performed.

The reference item degraded normally (63% by within 14 days). By the end of the test, the reference item was degraded to an average of 72%.

At the end of the 28-day exposure period, the mean extent of biodegradation of the test item was 9%. No significant biodegradation of C16 18FA-TEPA-compound occurred under the test conditions within 28 days and the pass level for ready biodegradability of at least 60% degradation 10-day window within the 28-day period of the test wasnot reached.

The extent of biodegradation in the toxicity control showed a similar course over the 28-day exposure period when compared to the procedure control containing the reference item, only. Within 14 days of exposure, the extent of biodegradation was 35%. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 27.1 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.