reaction product of alumina and sulfuric acid

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:

72h

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

certified by andesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Kaiser-Friedrich-Str. 7, D-55116 Mainz, Germany

Test material

Test material information

Constituent 1

Reference substance name:

reaction product of alumina and sulfuric acid

EC Number:

812-508-7

Cas Number:

1093112-19-6

Molecular formula:

unspecified, UVCB substance

IUPAC Name:

reaction product of alumina and sulfuric acid

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

at the start and the end of the test, the content of aluminium (Al) and sulphur (S) was determined with and without algae by ICP-OES

Test solutions

Vehicle:

yes

Remarks:

WAF (water-accommodated fractions)

Details on test solutions:

Before each experiment, the water-accommodated fractions (WAF) of the concentrations to be tetsted were prepared. This was done by weighing each nominal load, adding the corresponding amount of demineralised water and shaking vigorously for 24 hours. The resulting solution was filtrated through 0.45 µm nylon filters. After filtration the required amount of minerals were added. The test solution was checked for any clouding or precipitation, but nothing was found.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Desmodesmus subspicatus (Chlorophyceae), strain 86.81
obtained by MBM Sciencebridge GmbH (Institut für Pflanzenphysiologie, Universität Göttingen) in January 2016 and kept as stock culture on solid agar plates

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

no

Test conditions

Test temperature:

21.7 - 23.0°C

pH:

7.5 - 9.0

Dissolved oxygen:

not measured

Nominal and measured concentrations:

nominal concentrations: 1.0/3.2/10/100 mg/L, blank control (demineralised water)

Details on test conditions:

6 replicates for the blank control, 3 replicates for each treatment
glass flasks total volume 65 mL, test solution with nutrient medium and algae,
incubated open (covered with perforated plastic foil) and skaked on an orbital shaker to keep the algae in suspension
lighting 7200 lux
Before the start of the experiment and every 24 h the cell number waws determined with an electronic particle counter
before and at the end of the experiment, the pH was measured and samples for the analytical determination were taken
At the end of the test the treatments were examined microscopically

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Effect concentrations 5

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

other: yield

Effect concentrations 6

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

other: yield

Effect concentrations 7

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

other: yield

Effect concentrations 8

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

other: yield

Details on results:

All data were obtained by the same experiment. The NOEC is >/= 100 mg/L (growth rate, yield) for desmodesmus subspicatus in this experiment.

Results with reference substance (positive control):

The 72h-EC50 of potassium dichromate was determined in a separate reference test. The values lay within the range of the laboratory.
EC50 (growth rate): 0.73 -1.10 mg/L, EC50 (yield): 0.21-0.66 mg/L

Reported statistics and error estimates:

no

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72h NOEC for Desmodesmus subspicatus (growth rate, yield) is >/= 100 mg/L (nominal concentration of the test substance).