Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2013-01-28 to 2013-2-28
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well documented guideline study with certificated GLP compliance

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Ministerium für Arbeit, Integration und Soziales des Landes Nordrhein-Westfalen

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
Name as cited in the study report: Additin E 459
Other name: Triethylene glycol dimaleate
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
At the time of the testing the CAS Number that was used for Triethylene glycol dimaleate was 66790-57-6
In the course of the project the CAS Number 109828-01-5 was assigned, as this number describes better the structure of the main compound

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Control : at 72 hours
Test concentration : at 0 and 72 hours

Test solutions

Vehicle:
no
Details on test solutions:
99.8 mg of the test item were added to 1 litre of dilution water, treated for 60 seconds at 8000 rpm with an ultra turrax and afterwards stirred for 24 h on a magnetic stirrer. The pH was measured to be 5.8 and was adjusted to pH 8.3.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
Strain of the test species obtained from 'The Collection of Algal Cultures' of the Institute of Plant Physiology at the University of Göttingen (Germany).

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Post exposure observation period:
No details available

Test conditions

Hardness:
1.3 °dH, corresponding to 22.5 mg/L CaCO3
Test temperature:
21 - 24°C
pH:
8.1 (start)
9.8 (end)
Dissolved oxygen:
No details available
Salinity:
No details available
Nominal and measured concentrations:
100 mg/L (nominal concentration)
Details on test conditions:
Test vessels : 300 mL Erlenmeyer flasks with cotton stoppers, test volume: 100 mL
Culturing apparatus : Shaking incubator in which a temperature in the range 21 °C to 24 °C was maintained at +/- 2 °C, and continuous uniform illumination was provided in the spectral range 400 to 700 nm. Temperature was measured and recorded daily
Reference substance (positive control):
no
Remarks:
not stringent according to OECD 201

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth rate (index r), relative to control cultures grown under identical conditions. Growth rates were also used to calculate a No Observed Effect Concentration and a Lowest Observed Effect Concentration according to STUDENT-t test for Homogeneous Variances
Results with reference substance (positive control):
Not applicable
Reported statistics and error estimates:
No details available

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Validity criteria of the EU method C.3 guideline were met
Conclusions:
No toxic effects against algae were observed at a limit test concentration of 100 mg/L under exposure conditions.
Executive summary:

A study was performed to assess the adverse effects of Additin E 459 on the growth rate (= rate of increase in cell density with time) and the yield (= biomass at time t minus initial biomass) of the planktonic freshwater algal species Desmodesmus subspicatus (former name: Scenedesmus subspicatus) over several generations.

The study was conducted in accordance with Commission Regulation (EC) No 761/2009 amending Regulation No 440/2008, Method C.3 ‘Freshwater Alga and Cyanobacteria, Growth inhibition test’ (2009) which is equivalent to OECD Guideline for Testing of Chemicals No. 201 (2006).

Exponentially growing algal cells were exposed for a period of 72 hours to a limit test concentration of nominally 100 mg/L of Additin E 459 dissolved in dilution water. Auxiliaries used to prepare the test media were an ultra turrax and a magnetic stirrer.

The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth rate (index r), relative to control cultures grown under identical conditions. Growth rates were also used to calculate a No Observed Effect Concentration and a Lowest Observed Effect Concentration according to STUDENT-t test for Homogeneous Variances. The following values were determined:

Results [mg/L]:

ErC 50* (0-72 h): > 100

ErC 10* (0-72 h): > 100

NOEC [r]* (ta 0.05): = 100

LOEC [r]* (ta 0.05): > 100

No toxic effects against algae were observed at a limit test concentration of 100 mg/L under exposure conditions.

* Reduction of growth rate (ErCx, NOEC [r]) is the preferred endpoint according to OECD 201 and for regulatory purposes in the EU. Results relating to yield (EyCx, NOEC [y]) were calculated to fulfil regulatory requirements in some countries (but not in the EU) and are given in the results section of this report.

The results are expressed in terms of nominal concentrations. Effective concentrations correspond to 104.8 % of nominal values at 0 hours, and to 99.0 % of nominal values at 72 hours.