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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:
06 September 2010 - 29 October 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Compliant to GLP and testing guideline; adequate coherence between data, comments and conclusions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): UDMH (Unsymmetrical Dimethylhydrazine)
- Physical state: liquid
- Analytical purity: 99.4%
- Impurities (identity and concentrations): water 0.2%, amines 0.4%, methanol <0.01%, chlorides 0.0022%, iron < 0.00006%, mechanical impurities < 0.0001%
- Purity test date: 10 september 2008
- Lot/batch No.: 1
- Expiration date of the lot/batch: 23 january 2012 (supplier's indication by e-mail)
- Storage conditions of test material: at room temperature.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: all
- Sampling method: aliquot (approximately 10 mL)
- Sample storage conditions before analysis: analyzed <1h after sampling

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no, soluble

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Strain: Pseudokirchnerella subcapitata
- Source (laboratory, culture collection): internal culture lab

ACCLIMATION: none

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
no

Test conditions

Test temperature:
23°C +/- 2°C
pH:
8.1 in test medium non-treated
Nominal and measured concentrations:
Theoretical: 0.21, 0.47, 1.03, 2.27 and 5 mg/L
Nominal (based on weighed amounts for preparations): 0.24, 0.54, 1.18, 2.60 and 5.74 mg/L
Measured (geometric average): 0.16, 0.32, 0.77, 1.78 and 4.08 mg/L
Details on test conditions:
TEST SYSTEM
- No. of organisms per vessel: 10000 cells per mL
- No. of vessels per concentration (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: demineralized water added with (Calcium, Ammonium, Manganese, Zinc, Cobalt and Magnesium) chlorides, Magnesium sulphate, Potassium dihydrogenocarbonate, iron, EDTA, Orthoboric acid, Sodium molybdate and Sodium hydrogenocarbonate.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod, intensity: continuous light at approximately 7000 lux

EFFECT PARAMETERS MEASURED: growth (derived from optical density) at 24, 48 and 72h
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.09 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 1.91-2.28 mg/L
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.35 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 0.27-0.44 mg/L
Results with reference substance (positive control):
potassium dichromate August 30th, 2010: ErC50 = 1.36 mg/L [1.31 – 1.42]

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
For UDMH, ErC50 in algae was 2.09 mg/L over 72h.
Executive summary:

UDMH was tested in static conditions for acute toxicity toward Pseudokirchneriella subcapitata. The ErC50 (growth rate) over 72h was 2.09 mg/L, based on measured time-weighed geometric average concentrations.