L-Lysine, N2,N6-bis[N-(1-oxododecyl)glutamyl]-, sodium salt (1:?)

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22nd October 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies which did not affect the quality of relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.6800 (Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals)

Deviations:

no

GLP compliance:

yes

Remarks:

GLP inspection was in 2008, and valid for 2 years.

Test material

Test material information

Constituent 1

Reference substance name:

Pellicer

IUPAC Name:

Pellicer

Details on test material:

Name: Pellicer
Lot No.: 01-09-17
Chemical name: L-Lysine, N2, N6-bis[N-(1-oxododecyl)-L-α (or γ)- glutamyl]-, sodium salt (1;?)
Purity: 91 %
Appearance: White powder
Storage: At room temperature in the dark, protected from humidity
Expiry date: 17 January 2011

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

162.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 95% Confidence limits: 130.1 - 202.2 mg/L

Effect concentrations 2

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Any other information on results incl. tables

In comparison to the inoculum controls the respiration rate of the activated sludge was not inhibited in the concentration of 31 mg/L test item. The respiration rate was inhibited between 45.2 % and 83.3 % in the examined nominal test concentration range 100 – 1000 mg /L (95% Confidence limits: 130.1 - 202.2 mg/L). Concentrations exceeding 1000 mg/L nominal were not tested.

The 3-hour EC50 of 3,5-Dichlorophenol (positive control) was calculated to be 8.3 mg/L with 95 % confidence limits of 5.9 to 11.8 mg/L.

VALIDITY CRITERIA :

- The respiration rates of the two controls did not differ by more than 15 %

- The 3-hour EC50 of the reference item 3,5-Dichlorophenol for the used activated sludge batch was determined to be in the range of 5 to 30 mg/L.

- The concentration of dissolved oxygen did not drop below 2.5 mg O2/L during the incubation period, and just before the measurements of the respiration rates the oxygen concentrations were at least 6.5 mg O2/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were met during this study.

Conclusions:

This study was carried out using OECD guidline 209 and EU method C11. The EC50 value was determined to be 162.2 mg/L (in the range of 100-1000 mg/L). The NOEC was determined to be < 10 mg/L.

Executive summary:

A laboratory test was carried out with Pellicer to evaluate the effect of the test item on microorganisms by measuring the respiration rate. The test concentrations (10, 31, 100, 313 and 1000 mg/L) were chosen to permit the determination of the EC50.

In comparison to the inoculum controls the respiration rate of the activated sludge was inhibited between 4.8 % and 83.3 % in the examined nominal test concentration range. The inhibition showed a dose-related tendency. The respiration rate was inhibited with 83.3 % at the highest concentration level of 1000 mg/L. Concentrations exceeding 1000 mg/L nominal were not tested.

In parallel to the study with the test item, the reference item 3,5-Dichlorophenol was tested (the nominal test concentrations of 5, 16 and 32 mg/L) under otherwise identical test conditions.

The 3-hour EC50 of 3,5-Dichlorophenol was calculated to be 8.3 mg/L with 95 % confidence limits of 5.9 to 11.8 mg/L.

Based on measured inhibition rates the 3-hour EC50 value and the 95 %-confidence limits were calculated by Probit analysis using TOXSTAT software:

EC50: 162.2 mg/L (130.1 – 202.2 mg/L))

The EC50 value was determined to be 162.2 mg/L (in the range of 100-1000 mg/L).

The NOEC was determined to be < 10 mg/L.

The NOEC for respiration rates was not based on the results of a statistical analysis, but it is biologically justified. The respiration rates were inhibited and influenced dose dependently in the whole concentration range. The calculated respiration rates of the test item treated groups were not in the historical control data range (0.518 ± 0.074).