[No public or meaningful name is available]

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

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material: Bis[4-(5-chloro-2-hydroxyphenylazo)-3-methyl-1-phenyl-5-pyrazolate] Ferrate, hydrogen
- Substance type: toner additive; charge control agent
- Physical state: solid
- Analytical purity: 98.02% (HPLC)
- Impurities (identity and concentrations): unknown: 0.98% (HPLC); water: 1.0%
- Composition of test material, percentage of components: ---
- Isomers composition: ---
- Purity test date: 5-Oct-07
- Lot/batch No.: 002-2
- Expiration date of the lot/batch: 2-Oct-09
- Stability under test conditions: stable
- Storage condition of test material: dry, cool; under exclusion of light
- Other: ---

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg test item was transferred to 1 l growth medium in a 2 l flask with a drain port near the bottom. The preparation was stirred at 200 rpm for 48 h at 20°C.
- Eluate: Filtration of test item particles to separate the eluate (0.22 µm filter; Millipore MCE-MF, cellulose nitrate and acetyl cellulose, no. GSWP04700) without pre-filtration. The obtained test solution representing the highest concentration was diluted with growth medium using a spacing factor of 2 and 10 to prepare the other 5 test concentrations,

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): SAG, Culture Collection of Algae at Pflanzenphysiologisches Institut of the Unversity of Göttingen, Albrecht von Haller Institut, Untere Klarspüle 2, 37073 Göttingen, Catalogue No. 86.81
- Method of cultivation: Stock culture were maintained according to OECD guidelines. Three days prior to testing a pre-culture was established in OECD growth medium to obtain exponentially growing algae for the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

None

Test conditions

Hardness:

A sterilized synthetic growth medium (OECD medium) according to OECD 201 was used for culture and preparation of the test medium.

Test temperature:

22.0-22.5°C

pH:

Controls: 7.47-8.17; test cultures: at the beginning 7.30-7.45, at the end of test 7.97-8.28

Dissolved oxygen:

-

Salinity:

-

Nominal and measured concentrations:

Nominal: 0.63, 6.25, 12.5, 25.0, 50.0 and 100 mg/l; measured: all < 1.71 µg/l

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): Covered with silicone-sponge caps (sterilized prior to use)
- Material, size, headspace, fill volume: 250 ml conical glass flasks
- Initial cells density: 10,000 cells/ml
- No. of organisms per vessel: 1,000,000 cells
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 50 - < 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The ErC50 for growth rate was calculated to be 112 mg/l based on nominal loading. The EC50 values for yield and biomass were at loadings of 69.9 and 73.9 mg/l, resp. The NOEC for all parameters was determined to be 50.0 mg/l nominal loading.Chemical analysis: conc. < 1.71 µg/l in all samples.