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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:
November - december 2018
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
other:
Version / remarks:
EPA-821-R-02-013
Deviations:
no
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Version / remarks:
1981
Principles of method if other than guideline:
Similar conditions compared to OECD 201 assay regarding initial biomass and concentration, temperature range, test duration
GLP compliance:
yes
Remarks:
NELAC certification - generation of environmental laboratory data of known and documented quality in a cost-effective manner through the development of USA recognized standards for environmental laboratory accreditation

Test material

Constituent 1
Chemical structure
Reference substance name:
(ethyl-3-oxobutanoato-O'1,O'3)(2-dimethylaminoethanolato)(1-methoxypropan-2-olato)aluminium(III), dimerised
EC Number:
402-370-2
EC Name:
(ethyl-3-oxobutanoato-O'1,O'3)(2-dimethylaminoethanolato)(1-methoxypropan-2-olato)aluminium(III), dimerised
Cas Number:
149057-70-5
Molecular formula:
C14H28AlNO6
IUPAC Name:
octaaluminium(3+) octakis((2Z)-4-ethoxy-4-oxobut-2-en-2-olate) octakis(1-methoxypropan-2-olate) octakis(2-(dimethylamino)ethan-1-olate)
Specific details on test material used for the study:
batch 0002294851

Sampling and analysis

Analytical monitoring:
no
Remarks:
complexe substance difficult to analyse

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The freshwater algae Pseudokirchneriella subcapitata was obtained from the University of Waterloo, Canadian Phycological Culture Centre (Waterloo, Ontario, Canada). The algae were cultured in accordance with US EPA (2002b) methodology. Algae lot # PS-039 was received on 19 October 2018.

Study design

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

Test conditions

Hardness:
moderately hard reconstituted water
Test temperature:
target temperature of 251C
pH:
measured at test initiation
Dissolved oxygen:
measured at test initiation
Salinity:
not specified
Conductivity:
measured at test initiation
Nominal and measured concentrations:
nominal 0.1, 1.0, 10, 100 and 1,000 mg/L.
Details on test conditions:
The Water-Accomodated Fractions (WAFs) of the sample were prepared following the guidance in the ASTM D6081-98 (ASTM 2004) Standard Practice. Chambers for the WAF preparation were 2-L glass beakers. The volume of moderately hard reconstituted water used to prepare the five different loads of WAF was 1500 ml, which represented a 1:1 height to diameter ratio in the 2-L beaker. The five loads of WAF were: 0.1 mg/L, 1.0 mg/L, 10 mg/L, 100 mg/L, and 1,000 mg/L. Once the correct weight of sample was loaded into the beakers, 1500 ml of media was slowly siphoned into each of the beakers. A stir bar was added to each beaker, and the beakers were then placed on stir plates for overnight mixing. The speed of the stirring was adjusted so that there was a vortex of approximately 15 percent of the water column. The loads were mixed for 21 hours at 25ºC after which the solutions were allowed to settle for three hours. The WAF preparations were siphoned out of the beakers for testing.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
other: EC25
Effect conc.:
ca. 14.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 51.7 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Details on results:
the mean cell density after 72 hours in the test concentrations ranged from 21,250 to 610,625 cells/ml
Results with reference substance (positive control):
mean cell density after 72 hours in the test concentration was 762,500 cells/ml in the control
The results of the reference toxicant tests were acceptable and fell within the established laboratory control chart limits. For P. subcapitata, the 96-hour EC50 was 0.45 mg/L Cr+6, and acceptable control chart range was 0-1.2 mg/L Cr+6.
Reported statistics and error estimates:
Shapiro-Wilk's test indicates normal distribution (p>0.01)
Bartlett's test indicates equal variances (p=0.19)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In the 72-hour Pseudokirchneriella subcapitata definitive acute toxicity test with the AOC 1020X, the mean cell density after 72 hours in the test concentrations ranged from 21,250 to 610,625 cells/ml, compared to 762,500 cells/ml in the control. The P. subcapitata 72-hour EC25 and EC50 were 14.8 and 51.7 mg/L AOC 1020X.
Executive summary:

In the 72-hour Pseudokirchneriella subcapitata definitive acute toxicity test following US EPA standard EPA-821-R-02-013, the mean cell density after 72 hours in the test concentrations ranged from 21,250 to 610,625 cells/ml, compared to 762,500 cells/ml in the control. The P. subcapitata 72-hour EC25 and EC50 were 14.8 and 51.7 mg/L AOC 1020X.