Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
31 January 2017 - 03 February 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Specific details on test material used for the study:
Batch/Lot Number: 150205
Description: Blue powder
Purity: As a UVCB, purity is considered as 100%
Expiry date: 05 February 2019
Storage condition: Controlled room temperature (15-25°C, below 70 RH%)
Analytical monitoring:
yes
Details on sampling:
Because the test item is poorly soluble in water, a test solution was prepared using a saturated solution method (water accommodated fraction, WAF) according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23.
- Concentrations: nominal loading rate of 100 mg/L
- Sampling method: Samples were taken at the beginning and at the end of the experiment. Duplicate
samples were taken from four replicate at the applied test concentration as well as from
the control.
Samples were taken in plastic tubes, acidified with pure nitric acid
(9 mL sample + 1 mL HNO3) (stored under test conditions until analysis) in agreement with the requirements of the PI. To avoid any problems with microparticles, therefore the samples were membrane filtrated before acidification. After sampling, one set of the samples was stored under test conditions and then sent to the Test Site for analysis. One set of the samples is retained as a back-up at the Test Facility, thus these samples were frozen and kept approximately at -20°C at the Test Facility, if required for any confirmatory analyses (discarded after satisfactory results were obtained on the first set of).
Vehicle:
no
Details on test solutions:
Because the test item is poorly soluble in water, a test solution was prepared using a saturated solution method (water accommodated fraction, WAF) according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23.
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: 61.81 SAG (identical strains: CCAP 278/4; UTEX 1648; ATCC 22662)
- Age of inoculum (at test initiation): four days
- Method of cultivation: onto agar

ACCLIMATION
- Culturing media and conditions (same as test or not): pre-culture incubated under the same conditions as the test
- Any deformed or abnormal cells observed: no
Test type:
static
Water media type:
other: OECD Medium
Limit test:
yes
Total exposure duration:
72 h
Test temperature:
In flasks: 22.8 – 22.9 °C
Within the climate chamber: 22.3 and 23.4 °C
pH:
7.29 – 8.80
Nominal and measured concentrations:
100 mg/L nominal loading rate WAF
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type: closed
- Material, size, headspace, fill volume: 250 mL
- Aeration: The flasks were covered with air-permeable stoppers
- Type of flow-through (e.g. peristaltic or proportional diluter): na
- Renewal rate of test solution (frequency/flow rate): na
- Initial cells density: 10^4 algal cells per mL
- No. of organisms per vessel: 10^4 algal cells per mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): na

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted algal growth medium (OECD medium, according to OECD 201)
- Culture medium different from test medium: yes
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: No
- Photoperiod: continuously illuminated
- Light intensity and quality: 8418 lux (equivalent to ~114 μE/m2/s), fluorescent lamps (with a spectral range of 400-700 nm)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chamber

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 100, 10 and 1 mg/L nominal loading rates WAFs
- Results used to determine the conditions for the definitive study: no significant inhibition of algal growth was observed during the preliminary range-finding test
Reference substance (positive control):
yes
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Remarks:
nominal loading rate WAF
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Remarks:
nominal loading rate WAF
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Remarks:
nominal loading rate WAF
Basis for effect:
other: yield
Key result
Duration:
72 h
Dose descriptor:
NOELR
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Remarks:
nominal loading rate WAF
Basis for effect:
not specified
Key result
Duration:
72 h
Dose descriptor:
LOELR
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Remarks:
nominal loading rate WAF
Basis for effect:
not specified
Results with reference substance (positive control):
Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.
Date of the last study: 13 – 16 September 2016
- 72h ErC 50: 0.89 mg/L, (95 % confidence limits: 0.82 – 0.97 mg/L)
- 72h EyC 50: 0.53 mg/L, (95 % confidence limits: 0.49 – 0.58 mg/L)
- 72h EbC 50: 0.62 mg/L, (95 % confidence limits: 0.57 – 0.67 mg/L)
These values are within the range of laboratory ring test data.
Validity criteria fulfilled:
yes
Conclusions:
The effect of the test item was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum), over an exposure period of 72 hours. Under the conditions of this algal growth inhibition test the calculated endpoints
for the effect of the test item were the following:
The 72h EbL50 value (biomass): > 100 mg/L nominal loading rate WAF
The 72h ErL50 value (growth rate): > 100 mg/L nominal loading rate WAF
The 72h EyL50 value (yield): > 100 mg/L nominal loading rate WAF
The 72h No-Observed Effect Loading Rate (NOELR): 100 mg/L nominal loading rate WAF
The 72h Lowest Observed Effect Loading Rate (LOELR): > 100 mg/L nominal loading rate WAF

Description of key information

The 72h EbL50 value (biomass): > 100 mg/L nominal loading rate WAF

The 72h ErL50 value (growth rate): > 100 mg/L nominal loading rate WAF

The 72h EyL50 value (yield): > 100 mg/L nominal loading rate WAF

The 72h No-Observed Effect Loading Rate (NOELR): 100 mg/L nominal loading rate WAF

The 72h Lowest Observed Effect Loading Rate (LOELR): > 100 mg/L nominal loading rate WAF

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L

Additional information

Categories Display